JP2019045129A - Air conditioning system - Google Patents

Abstract

To suppress cost and deterioration of workability in relation to the improvement of security with respect to refrigerant leakage.SOLUTION: An air conditioning system 100 includes an outdoor unit 10, a plurality of indoor units 40, refrigerant connection pipelines (La, Ga), and a cutoff valve 84 arranged on the refrigerant connection pipeline and for cutting off the flow of the refrigerant. The refrigerant connection pipeline includes: a plurality of indoor unit side connection pipes 82 communicating with the indoor units 40; an outdoor unit side connection pipe 81 communicating with the plurality of indoor unit side connection pipes 82; and a branch pipe 83 for connecting the plurality of indoor unit side connection pipes 82 and the outdoor unit side connection pipe 81. The outdoor unit side connection pipe 81 forms a refrigerant flow passage common to the refrigerant flowing to the indoor unit 40 side from the outdoor unit 10 side via the indoor unit side connection pipes 82 and the refrigerant flowing to the outdoor unit 10 from the indoor unit 40. The cutoff valve 84 is arranged on the outdoor unit side connection pipe 81.SELECTED DRAWING: Figure 1

Description

  The present disclosure relates to an air conditioning system.

  In the air conditioning system, there is a possibility that the refrigerant leaks from the refrigerant circuit due to damage to the equipment constituting the refrigerant circuit or poor installation. Therefore, it is necessary to take measures to ensure the safety when the refrigerant leaks. Become. In particular, recently, from the viewpoint of improving energy saving and reducing environmental load, for example, a slightly flammable refrigerant such as R32 (combustibility is not large, but the characteristic of burning when the concentration becomes a predetermined value (combustion lower limit concentration) or more is shown. And the demand for such measures is increasing.

  Conventionally, as measures against refrigerant leakage, for example, as disclosed in Japanese Patent Application Laid-Open No. 5-118720, a predetermined control valve (electromagnetic valve or motor-operated valve) is provided in the refrigerant circuit when refrigerant leakage is detected. By controlling the opening control valve to the closed state (minimum opening), the refrigerant flow to the indoor unit is obstructed, and the space where the indoor unit is installed (the living space or warehouse where people enter and exit) There has been proposed a method for suppressing further refrigerant leakage into an internal space or the like. In Patent Document 1, in an air conditioning system including a plurality of indoor units in the same refrigerant system, when a pair of control valves are arranged for each indoor unit on a communication pipe between the outdoor unit and the indoor unit, and refrigerant leakage occurs. The corresponding control valve is controlled to be closed.

  Here, in an air conditioning system applied in a large-scale facility such as a building or a factory, the number of indoor units to be constructed increases according to the size of the facility. Therefore, when a pair of control valves is arranged for each indoor unit as in Patent Document 1, the cost increases remarkably according to the number of indoor units.

  Further, the connecting pipe between the outdoor unit and the indoor unit is usually constructed in a narrow ceiling space. In this regard, when a control valve is arranged for each indoor unit as in Patent Document 1, it is necessary to install a large number of control valves on the connection pipe as the number of indoor units increases, and the work time required for construction and The labor will be remarkably increased and the workability will not be excellent.

  In relation to improving the security against refrigerant leakage, an air conditioning system that is excellent in cost control and workability is provided.

  An air conditioning system according to a first aspect is an air conditioning system that performs a refrigeration cycle in a refrigerant circuit, and includes an outdoor unit, a plurality of indoor units, a refrigerant communication pipe, and a control valve. The refrigerant communication pipe connects the outdoor unit and the indoor unit. The control valve is disposed on the refrigerant communication pipe. The control valve impedes the refrigerant flow. The refrigerant communication pipe includes a plurality of indoor side pipes, outdoor side pipes, and branch portions. The indoor side piping communicates with the corresponding indoor unit. The outdoor piping communicates with a plurality of corresponding indoor piping on the outdoor unit side. The branch portion connects the indoor-side piping group and the outdoor-side piping. An indoor side piping group is a piping group comprised by two or more indoor side piping. The outdoor pipe forms a common refrigerant flow path for both the refrigerant flowing from the outdoor unit side to the indoor unit side via the corresponding indoor pipe and the refrigerant flowing from the indoor unit to the outdoor unit via the corresponding indoor pipe. To do. The control valve is disposed on the outdoor pipe.

  In the air conditioning system according to the first aspect, the number of control valves increases according to the number of indoor units by disposing the control valves on the outdoor side piping to block the refrigerant flow to the plurality of indoor units. Is suppressed. That is, the flow of the refrigerant that flows from the outdoor pipe (outdoor unit side) to the corresponding indoor pipe group (a plurality of indoor units) when the refrigerant leaks by arranging the control valve closer to the outdoor unit than the indoor pipe group. Can be prevented. For this reason, it is not necessary to arrange a control valve for each indoor unit in order to ensure the safety related to refrigerant leakage, and the increase in the number of control valves according to the number of indoor units is suppressed.

  In addition, the refrigerant communication pipe between the outdoor unit and the indoor unit is usually constructed in a narrow ceiling space, and it is possible to suppress an increase in the number of control valves installed on the refrigerant communication pipe. Therefore, the increase in work time and labor required for construction is also suppressed.

  Therefore, in connection with improving the security against refrigerant leakage, cost reduction and workability improvement are promoted.

  An air conditioning system according to a second aspect is an air conditioning system that performs a refrigeration cycle in a refrigerant circuit, and includes an outdoor unit, a plurality of indoor units, a refrigerant communication pipe, and a control valve. The refrigerant communication pipe connects the outdoor unit and the indoor unit. The control valve is disposed on the refrigerant communication pipe. The control valve impedes the refrigerant flow. The refrigerant communication pipe includes a plurality of indoor side pipes, outdoor side pipes, and branch portions. The indoor side piping communicates with the corresponding indoor unit. The outdoor piping communicates with a plurality of corresponding indoor piping on the outdoor unit side. The branch portion connects the indoor-side piping group and the outdoor-side piping. An indoor side piping group is a piping group comprised by two or more indoor side piping. The outdoor pipe forms a common refrigerant flow path for both the refrigerant flowing from the outdoor unit side to the indoor unit side via the corresponding indoor pipe and the refrigerant flowing from the indoor unit to the outdoor unit via the corresponding indoor pipe. To do. A control valve is arrange | positioned on corresponding indoor side piping.

  In the air conditioning system according to the second aspect, an increase in the number of control valves according to the number of indoor units is suppressed. That is, the control valve for blocking the flow of the refrigerant to the plurality of indoor units is arranged on the indoor side pipe arranged on the outdoor unit side of these indoor units, so that the outdoor pipe (outdoor It becomes possible to prevent the flow of the refrigerant flowing from the unit side) to these indoor units. For this reason, it is not necessary to arrange a control valve for each indoor unit in order to ensure the safety related to refrigerant leakage, and the increase in the number of control valves according to the number of indoor units is suppressed.

  In addition, the refrigerant communication pipe between the outdoor unit and the indoor unit is usually constructed in a narrow ceiling space, and it is possible to suppress an increase in the number of control valves installed on the refrigerant communication pipe. Therefore, the increase in work time and labor required for construction is also suppressed. Moreover, it becomes possible to use a control valve with a small dimension by arrange | positioning a control valve on indoor side piping compared with the case where a control valve is arrange | positioned on outdoor side piping. In connection with this, downsizing is promoted, and a decrease in workability is suppressed even in a narrow space.

  Therefore, in connection with improving the security against refrigerant leakage, cost reduction and workability improvement are promoted.

  The air conditioning system which concerns on a 3rd viewpoint is an air conditioning system which concerns on a 1st viewpoint or a 2nd viewpoint, Comprising: Refrigerant communication piping contains multiple 1st parts. The first part is a part having one outdoor pipe, one branch part, and an indoor pipe group. When the control valve is arranged on the outdoor pipe, the control valve is arranged on the outdoor pipe in a part of the first part. When the control valve is arranged on the indoor side pipe, the control valve is arranged on the indoor side pipe in a part of the first part.

  Here, in the case where the refrigerant communication pipe includes a plurality of first parts, the control valve is arranged only in a specific first part (for example, the first part closest to the outdoor unit), so that the other first part Even if the control valve is omitted, it is possible to prevent the flow of refrigerant flowing from the outdoor unit side to each indoor unit side. For this reason, in the case where a plurality of first parts are included in the refrigerant communication pipe, the number of control valves can be increased while ensuring the safety of refrigerant leakage by arranging the control valves only in a part of the first parts. It can be suppressed from increasing. The air conditioning system which concerns on a 2nd viewpoint is based on the thought which concerns. Therefore, in connection with improving the security against refrigerant leakage, cost reduction and workability improvement are further promoted.

  The air conditioning system which concerns on a 4th viewpoint is a refrigerant | coolant air conditioning system which concerns on either of the 1st viewpoint to the 3rd viewpoint, Comprising: A refrigerant | coolant communication piping contains a gas side communication piping and a liquid side communication piping. The gas side communication pipe is a pipe through which a low-pressure refrigerant flows. The liquid side communication pipe is a pipe through which a high-pressure or intermediate-pressure refrigerant flows. When the control valve is disposed on the outdoor pipe, the control valve is disposed on the outdoor pipe included in the gas side communication pipe. When the control valve is arranged on the indoor side pipe, the control valve is arranged on the indoor side pipe included in the gas side communication pipe.

  Here, in the outdoor unit or the indoor unit, an electronic expansion valve for reducing the pressure of the refrigerant is usually disposed on the refrigerant flow path communicating with the liquid side communication pipe. When the refrigerant leaks, it is possible to prevent the flow of the refrigerant flowing from the outdoor unit to the indoor unit through the liquid side connection pipe by controlling the electronic expansion valve to the minimum opening. On the other hand, since there are many cases in which a control valve similar to the electronic expansion valve is not arranged on the refrigerant flow path communicating with the gas side communication pipe, in order to ensure the security against refrigerant leakage, the indoor unit is connected via the gas side communication pipe. It is important to prevent the flow of refrigerant toward the side.

  In the air conditioning system according to the third aspect, the control valve is arranged on the outdoor side pipe included in the gas side communication pipe, so that the increase in the number of control valves is suppressed, and the security against refrigerant leakage is ensured. Promoted.

  The air conditioning system which concerns on a 5th viewpoint is an air conditioning system which concerns on a 4th viewpoint, Comprising: When a control valve is arrange | positioned on outdoor side piping, it arrange | positions also on outdoor side piping contained in liquid side connection piping Is done. When the control valve is arranged on the indoor side pipe, the control valve is also arranged on the indoor side pipe included in the liquid side connecting pipe.

  In the air conditioning system according to the fourth aspect, the control valve is also arranged on the outdoor side pipe included in the liquid side communication pipe, thereby further ensuring the security against refrigerant leakage.

  The air conditioning system which concerns on a 6th viewpoint is an air conditioning system which concerns on either of the 1st viewpoint to the 5th viewpoint, Comprising: An indoor unit contains a motor operated valve. The motor-operated valve decompresses the refrigerant according to the opening degree during operation. When the refrigerant leaks, the motor-operated valve is closed to prevent the refrigerant flowing into the indoor unit.

  In the air conditioning system according to the fifth aspect, an electric valve that prevents the flow of the refrigerant by being controlled in a closed state when refrigerant leakage occurs is arranged in the indoor unit, so that when the refrigerant leaks, the outdoor unit can transfer from the outdoor unit to the indoor unit. It becomes possible to cut off the flow of the refrigerant more reliably. Therefore, ensuring safety against refrigerant leakage is further promoted.

The air conditioning system according to the seventh aspect is the air conditioning system according to any of the first to sixth aspects, and when the control valve is disposed on the outdoor pipe, the following A, B and C: It is arrange | positioned on any / all outdoor piping. When the control valve is arranged on the indoor side pipe, it is arranged on any / all of the following D, E and F indoor pipes.
A: Outdoor piping arranged between a plurality of indoor units whose total capacity is equal to or less than a first threshold and an outdoor unit B: A plurality of indoor units whose total number is equal to or less than a second threshold, and an outdoor unit Outdoor pipe C arranged between the outdoor unit pipe D: the outdoor pipe D having a total capacity of refrigerant communication pipes located on the indoor unit side being a third threshold value or less, and a plurality of indoor units having a total capacity being a fourth threshold value or less. The indoor side pipe E arranged between the outdoor unit and the outdoor unit. The indoor side pipe F arranged between the plurality of indoor units whose total number is equal to or smaller than the fifth threshold and the outdoor unit F: on the indoor unit side. Indoor piping where the total capacity of the refrigerant communication piping positioned is not more than the sixth threshold value

  This makes it necessary to shut off the refrigerant in view of safety (for example, lower combustion limit concentration) when refrigerant leakage occurs, depending on the scale and environment of the facility where the air conditioning system is installed (outdoors) In the piping), the control valve can be accurately arranged. Therefore, ensuring the security against refrigerant leakage is further promoted while the increase in the number of control valves is suppressed.

  An air conditioning system according to an eighth aspect is the air conditioning system according to the seventh aspect, wherein the first threshold, the second threshold, the third threshold, the fourth threshold, the fifth threshold, and the sixth threshold are an indoor unit Is set based on the size of one of the target spaces where air conditioning is performed.

  As a result, depending on the scale and environment of the facility where the air conditioning system is installed, the control valve is installed in the part (outdoor piping) where it is necessary to shut off the refrigerant in view of the safety when refrigerant leakage occurs. Accurate placement is further facilitated. That is, the first threshold value, the second threshold value, the third threshold value, the fourth threshold value, the fifth threshold value, and / or the sixth threshold value, which are used as a reference when determining the arrangement position of the control valve, are targets for installing the indoor unit It can be set based on a risk value (combustion lower limit concentration, oxygen deficiency concentration, etc.) determined according to the size of the space (for example, the narrowest target space). Therefore, ensuring the security against refrigerant leakage is further promoted while the increase in the number of control valves is suppressed.

  The air conditioning system which concerns on a 9th viewpoint is an air conditioning system which concerns on either of the 1st viewpoint to the 8th viewpoint, Comprising: An outdoor side piping and / or indoor side piping are comprised integrally with a branch part and a control valve. Thereby, installation of a control valve becomes easy and it is further suppressed that the working time and labor which construction requires increase. Therefore, in connection with improving the security against refrigerant leakage, the workability improvement is further promoted.

  An air conditioning system according to a tenth aspect is the air conditioning system according to the ninth aspect, wherein the refrigerant communication pipe includes a branch pipe unit. The branch pipe unit is assembled in advance and connected to other pipes at the construction site. The branch pipe unit includes an outdoor pipe and / or an indoor pipe, a branch portion, and a control valve that are integrally formed.

  This makes it particularly easy to install the control valve and further suppresses an increase in work time and labor required for construction. Therefore, in connection with improving the security against refrigerant leakage, the workability improvement is further promoted.

  An air conditioning system according to an eleventh aspect is the air conditioning system according to any one of the first to tenth aspects, and any of the valves arranged in the refrigerant circuit has a liquid seal suppression structure. Instead of / with this, a liquid seal suppression mechanism is arranged in the refrigerant circuit. The liquid seal suppression structure is a structure that suppresses formation of a liquid seal circuit in the refrigerant circuit when the control valve is closed. The liquid seal suppression mechanism is a mechanism that suppresses the formation of a liquid seal circuit in the refrigerant circuit when the control valve is closed. Thereby, when a refrigerant leak arises and a control valve will be in a closed state, it is suppressed that a liquid seal circuit is formed in a refrigerant circuit.

  The liquid seal suppression structure is not particularly limited as long as it is a structure that suppresses the formation of the liquid seal circuit. For example, as the liquid seal suppression structure, a minute flow path that allows a small amount of refrigerant to pass in the closed state may be formed in the valve. In addition, for example, as a liquid seal suppression structure, a valve may be configured to allow a small amount of refrigerant to pass when a pressure higher than a predetermined value is applied even in a closed state.

  The liquid seal suppression mechanism is not particularly limited as long as it is a mechanism that suppresses the formation of the liquid seal circuit. For example, in the refrigerant circuit, a pipe that forms a bypass circuit that bypasses the refrigerant from the flow path on one end side of the control valve to the flow path on the other end side may be arranged as a liquid seal suppression mechanism. In such a case, the liquid seal suppression mechanism may include a check valve that is arranged on the bypass circuit and allows the refrigerant to flow only in one direction, or an on-off valve that switches between opening and closing of the bypass circuit.

1 is a schematic configuration diagram of an air conditioning system according to an embodiment of the present disclosure. The schematic block diagram of a main-body unit. The schematic diagram which showed an example of the installation aspect of a branch pipe unit. The block diagram which showed roughly the controller and each part connected to a controller. The flowchart which showed an example of the flow of a process of a controller. The schematic block diagram of the air conditioning system which concerns on the modification 1. FIG. The schematic block diagram of the air conditioning system which concerns on the modification 9. FIG. FIG. 11 is a schematic configuration diagram of a main unit according to Modification Example 10. The schematic diagram which showed an example of the installation aspect of the branch pipe unit which has a main body unit which concerns on the modification 10. As shown in FIG. The schematic block diagram of the main body unit which concerns on the modification 11. As shown in FIG. The schematic block diagram of the main body unit which concerns on the modification 12. FIG. The schematic block diagram of the main body unit which concerns on the modification 13. As shown in FIG. The schematic block diagram of the main body unit which concerns on the modification 14. The schematic block diagram of the main body unit which concerns on the modification 15. FIG. FIG. 16 is a schematic configuration diagram of a main unit according to Modification Example 16. FIG. 16 is a schematic configuration diagram of another main body unit according to Modification Example 16. The schematic block diagram of the main body unit which concerns on the modification 17. FIG. The schematic block diagram of the air conditioning system which concerns on the modification 18. FIG.

  Hereinafter, an air conditioning system 100 according to an embodiment of the present disclosure will be described with reference to the drawings. The following embodiment is a specific example, does not limit the technical scope, and can be appropriately changed without departing from the gist. In the present specification, “liquid refrigerant” includes not only a liquid refrigerant in a saturated liquid state but also a gas-liquid two-phase refrigerant in a gas-liquid two-phase state. The “closed state” is a minimum opening (including a fully closed state) that the valve can take, and the “open state” is an opening larger than the minimum opening.

(1) Air conditioning system 100
FIG. 1 is a schematic configuration diagram of an air conditioning system 100. The air conditioning system 100 is a refrigeration apparatus that performs air conditioning such as cooling or heating of a target space (a living space, a storage space, a low-temperature warehouse, a transport container, or the like) by a vapor compression refrigeration cycle. The air conditioning system 100 mainly includes an outdoor unit 10, a plurality of indoor units 40 (40a, 40b), a liquid side communication pipe La and a gas side communication pipe Ga, and a plurality of refrigerant leakage sensors 60 (60a, 60b). A plurality of remote controllers 65 (65a, 65b) and a controller 70 for controlling the operation of the air conditioning system 100 are provided.

  In the air conditioning system 100, the refrigerant circuit RC is configured by connecting the outdoor unit 10 and the indoor unit 40 via the liquid side communication pipe La and the gas side communication pipe Ga. In the air conditioning system 100, the refrigerant circuit RC performs a refrigeration cycle in which the refrigerant is compressed, cooled or condensed, decompressed, heated or evaporated, and then compressed again. In the present embodiment, the refrigerant circuit RC is filled with slightly flammable R32 as a refrigerant for performing a vapor compression refrigeration cycle.

  The refrigerant circuit RC is mainly connected to the outdoor circuit RC1 configured in the outdoor unit 10, the indoor circuit RC2 configured in each indoor unit 40, the outdoor circuit RC1 and each indoor circuit RC2. And a communication circuit RC3. The communication circuit RC3 includes a liquid-side communication circuit RC3a that functions as a flow path for liquid refrigerant that flows between the outdoor unit 10 and the indoor unit 40, and gas refrigerant that flows between the outdoor unit 10 and the indoor unit 40. And a gas side communication circuit RC3b that functions as a flow path.

(1-1) Outdoor unit 10
The outdoor unit 10 is disposed outdoors. The outdoor unit 10 is connected to the plurality of indoor units 40 via the liquid side communication pipe La and the gas side communication pipe Ga, and constitutes a part of the refrigerant circuit RC (outdoor circuit RC1).

  The outdoor unit 10 mainly includes a plurality of refrigerant pipes (first pipe P1 to eleventh pipe P11), a compressor 11, an accumulator 12, and a four-way switching valve 13, as devices constituting the outdoor circuit RC1. The outdoor heat exchanger 14, the supercooler 15, the outdoor first electric valve 16, the outdoor second electric valve 17, the liquid side closing valve 19, and the gas side closing valve 20 are provided.

  The first pipe P1 connects the gas side shut-off valve 20 and the first port of the four-way switching valve 13. The second pipe P <b> 2 connects the inlet port of the accumulator 12 and the second port of the four-way switching valve 13. The third pipe P3 connects the outlet port of the accumulator 12 and the suction port of the compressor 11. The fourth pipe P4 connects the discharge port of the compressor 11 and the third port of the four-way switching valve 13. The fifth pipe P5 connects the fourth port of the four-way switching valve 13 and the gas side inlet / outlet of the outdoor heat exchanger 14. The sixth pipe P6 connects the liquid side inlet / outlet of the outdoor heat exchanger 14 and one end of the outdoor first electric valve 16. The seventh pipe P7 connects the other end of the outdoor first electric valve 16 and one end of the main flow path 151 of the subcooler 15. The eighth pipe P <b> 8 connects the other end of the main flow path 151 of the subcooler 15 and one end of the liquid side shut-off valve 19. The ninth pipe P9 connects a portion between both ends of the sixth pipe P6 and one end of the outdoor second electric valve 17. The tenth pipe P <b> 10 connects the other end of the outdoor second motor operated valve 17 and one end of the sub flow path 152 of the subcooler 15. The eleventh pipe P11 connects the other end of the sub flow path 152 of the subcooler 15 and a portion between both ends of the first pipe P1. Note that these refrigerant pipes (P1-P11) may actually be constituted by a single pipe, or may be constituted by connecting a plurality of pipes via joints or the like.

  The compressor 11 is a device that compresses a low-pressure refrigerant in the refrigeration cycle until it reaches a high pressure. In the present embodiment, the compressor 11 has a hermetic structure in which a displacement type compression element such as a rotary type or a scroll type is rotationally driven by a compressor motor (not shown). Here, the compressor motor can control the operation frequency by an inverter, and thus the capacity of the compressor 11 can be controlled.

  The accumulator 12 is a container for suppressing the liquid refrigerant from being excessively sucked into the compressor 11. The accumulator 12 has a predetermined volume according to the amount of refrigerant charged in the refrigerant circuit RC.

  The four-way switching valve 13 is a flow path switching valve for switching the refrigerant flow in the refrigerant circuit RC. The four-way switching valve 13 can be switched between a forward cycle state and a reverse cycle state. When the four-way switching valve 13 is in the normal cycle state, the first port (first pipe P1) and the second port (second pipe P2) are communicated with each other, and the third port (fourth pipe P4) and the fourth port are connected. (5th piping P5) is connected (refer the continuous line of the four-way selector valve 13 of FIG. 1). When the four-way switching valve 13 enters the reverse cycle state, the first port (first pipe P1) and the third port (fourth pipe P4) communicate with each other, and the second port (second pipe P2) and the fourth port. (5th piping P5) is connected (refer the broken line of the four-way selector valve 13 of FIG. 1).

  The outdoor heat exchanger 14 is a heat exchanger that functions as a refrigerant condenser (or radiator) or an evaporator. The outdoor heat exchanger 14 functions as a refrigerant condenser during normal cycle operation (operation in which the four-way switching valve 13 is in the normal cycle state). The outdoor heat exchanger 14 functions as a refrigerant evaporator during reverse cycle operation (operation in which the four-way switching valve 13 is in the reverse cycle state). The outdoor heat exchanger 14 includes a plurality of heat transfer tubes and heat transfer fins (not shown). The outdoor heat exchanger 14 is configured so that heat exchange is performed between the refrigerant in the heat transfer tube and the air passing through the periphery of the heat transfer tube or the heat transfer fin (the outdoor air flow described later). .

  The subcooler 15 is a heat exchanger that uses an inflowing refrigerant as a supercooled liquid refrigerant. The subcooler 15 is, for example, a double pipe heat exchanger, and the main channel 151 and the sub channel 152 are configured in the subcooler 15. The subcooler 15 is configured such that the refrigerant flowing through the main flow channel 151 and the sub flow channel 152 performs heat exchange.

  The outdoor first electric valve 16 is an electric valve capable of opening degree control, and depressurizes or adjusts the flow rate of the refrigerant flowing in accordance with the opening degree. The outdoor first electric valve 16 can be switched between an open state and a closed state. The outdoor first electric valve 16 is disposed between the outdoor heat exchanger 14 and the supercooler 15 (main flow path 151).

  The outdoor second motor-operated valve 17 is a motor-operated valve capable of opening degree control, and depressurizes or adjusts the flow rate of the refrigerant flowing in accordance with the opening degree. The outdoor second electric valve 17 can be switched between an open state and a closed state. The outdoor second electric valve 17 is disposed between the outdoor heat exchanger 14 and the supercooler 15 (sub-flow path 152).

  The liquid side shut-off valve 19 is a manual valve arranged at the connection portion between the eighth pipe P8 and the liquid side connecting pipe La. The liquid side shut-off valve 19 has one end connected to the eighth pipe P8 and the other end connected to the liquid side connecting pipe La.

  The gas side shut-off valve 20 is a manual valve disposed at a connection portion between the first pipe P1 and the gas side communication pipe Ga. The gas side shut-off valve 20 has one end connected to the first pipe P1 and the other end connected to the gas side communication pipe Ga.

  The outdoor unit 10 also has an outdoor fan 25 that generates an outdoor air flow that passes through the outdoor heat exchanger 14. The outdoor fan 25 is a blower that supplies an outdoor air flow as a cooling source or a heating source of the refrigerant flowing through the outdoor heat exchanger 14 to the outdoor heat exchanger 14. The outdoor fan 25 includes an outdoor fan motor (not shown) as a drive source, and the start and stop and the number of rotations are appropriately controlled according to the situation.

  Further, the outdoor unit 10 is provided with a plurality of outdoor sensors 26 (see FIG. 4) for detecting the state (mainly pressure or temperature) of the refrigerant in the refrigerant circuit RC. The outdoor sensor 26 is a pressure sensor, a temperature sensor such as a thermistor or a thermocouple. Examples of the outdoor sensor 26 include a suction pressure sensor that detects a suction pressure that is a refrigerant pressure on the suction side of the compressor 11, and a discharge pressure sensor that detects a discharge pressure that is a refrigerant pressure on the discharge side of the compressor 11. And a temperature sensor for detecting the temperature of the refrigerant in the outdoor heat exchanger 14.

  The outdoor unit 10 also has an outdoor unit control unit 30 that controls the operation and state of each device included in the outdoor unit 10. The outdoor unit control unit 30 includes a microcomputer having a CPU, a memory, and the like. The outdoor unit control unit 30 is electrically connected to each device (11, 13, 16, 17, 25, etc.) included in the outdoor unit 10 and the outdoor sensor 26, and inputs / outputs signals to / from each other. Moreover, the outdoor unit control part 30 transmits / receives a control signal etc. separately via the indoor unit control part 48 (after-mentioned) and remote control 65 of each indoor unit 40 via the communication line cb.

(1-2) Indoor unit 40
Each indoor unit 40 is connected to the outdoor unit 10 via the liquid side communication pipe La and the gas side communication pipe Ga. Each indoor unit 40 is arranged in parallel with the other indoor units 40 with respect to the outdoor unit 10. Each indoor unit 40 is arranged in the target space and constitutes a part of the refrigerant circuit RC (indoor side circuit RC2). Each of the indoor units 40 mainly includes a plurality of refrigerant pipes (17th pipe P17 to 18th pipe P18) and an indoor expansion valve 41 (“motorized valve” described in the claims) as devices constituting the indoor circuit RC2. And an indoor heat exchanger 42.

  The seventeenth pipe P17 connects the liquid side communication pipe La and the liquid side refrigerant inlet / outlet of the indoor heat exchanger 42. The eighteenth pipe P18 connects the gas side refrigerant inlet / outlet of the indoor heat exchanger 42 and the gas side communication pipe Ga. Note that these refrigerant pipes (P17 to P18) may actually be configured by a single pipe, or may be configured by connecting a plurality of pipes via joints or the like.

  The indoor expansion valve 41 is an electric valve capable of controlling the opening degree, and depressurizes or adjusts the flow rate of the refrigerant flowing in accordance with the opening degree. The indoor expansion valve 41 can be switched between an open state and a closed state. The indoor expansion valve 41 is disposed on the seventeenth pipe P <b> 17 and is located between the liquid side communication pipe La and the indoor heat exchanger 42.

  The indoor heat exchanger 42 is a heat exchanger that functions as a refrigerant evaporator or condenser (or radiator). The indoor heat exchanger 42 functions as a refrigerant evaporator during the normal cycle operation. The indoor heat exchanger 42 functions as a refrigerant condenser during reverse cycle operation. The indoor heat exchanger 42 includes a plurality of heat transfer tubes and heat transfer fins (not shown). The indoor heat exchanger 42 is configured such that heat exchange is performed between the refrigerant in the heat transfer tube and the air passing through the periphery of the heat transfer tube or the heat transfer fin (the indoor airflow described later). .

  The indoor unit 40 has an indoor fan 45 for sucking air in the target space, passing the air through the indoor heat exchanger 42 and exchanging heat with the refrigerant, and then sending it to the target space again. The indoor fan 45 is disposed in the target space. The indoor fan 45 includes an indoor fan motor (not shown) that is a drive source. The indoor fan 45 generates an indoor air flow as a heating source or a cooling source of the refrigerant flowing through the indoor heat exchanger 42 when driven.

  The indoor unit 40 is provided with an indoor side sensor 46 (see FIG. 4) for detecting the state (mainly pressure or temperature) of the refrigerant in the refrigerant circuit RC. The indoor side sensor 46 is a temperature sensor such as a pressure sensor, a thermistor, or a thermocouple. The indoor side sensor 46 includes, for example, a temperature sensor that detects the temperature of the refrigerant in the indoor heat exchanger 42, a pressure sensor that detects the pressure of the refrigerant in the indoor side circuit RC2, and the like.

  The indoor unit 40 also has an indoor unit control unit 48 that controls the operation / state of each device included in the indoor unit 40. The indoor unit control unit 48 includes a microcomputer including a CPU and a memory. The indoor unit control unit 48 is electrically connected to the devices (41, 45) included in the indoor unit 40 and the indoor side sensor 46, and inputs and outputs signals to and from each other. The indoor unit controller 48 is connected to the outdoor unit controller 30 and the remote controller 65 via the communication line cb, and transmits and receives control signals and the like.

(1-3) Liquid side communication pipe La, gas side connection pipe Ga
The liquid side connection pipe La and the gas side connection pipe Ga are refrigerant connection pipes that connect the outdoor unit 10 and the indoor units 40, and are constructed on site. The pipe lengths and pipe diameters of the liquid side connection pipe La and the gas side connection pipe Ga are appropriately selected according to the design specifications and the installation environment.

  The liquid side communication pipe La constitutes a liquid side communication circuit RC3 (liquid side communication circuit RC3a) between the outdoor unit 10 and each indoor unit 40, and is a pipe through which high-pressure or intermediate-pressure refrigerant flows during operation. The liquid side connection pipe La is configured by connecting a plurality of pipes, joints, and the like. Specifically, the liquid side connecting pipe La includes a first liquid side connecting pipe L1, a second liquid side connecting pipe L2, a third liquid side connecting pipe L3, and a branch portion BP (liquid side branch portion BPa). . The first liquid side connecting pipe L1, the second liquid side connecting pipe L2, and the third liquid side connecting pipe L3 may actually be constituted by a single pipe, or a plurality of pipes may be connected via joints or the like. It may be configured by connecting the pipes.

  One end of the first liquid side connecting pipe L1 is connected to the liquid side shut-off valve 19 of the outdoor unit 10, and the outdoor unit is more than the second liquid side connecting pipe L2, the third liquid side connecting pipe L3, and the liquid side branch portion BPa. 10 side. The second liquid side connecting pipe L2 and the third liquid side connecting pipe L3 are connected to the indoor unit 40 corresponding to one end. In the present embodiment, the second liquid side connecting pipe L2 corresponds to the indoor unit 40a, and the third liquid side connecting pipe L3 corresponds to the indoor unit 40b. The second liquid side connecting pipe L2 and the third liquid side connecting pipe L3 are arranged in parallel with each other. The first liquid side connecting pipe L1, the second liquid side connecting pipe L2, and the third liquid side connecting pipe L3 are connected and communicated at the liquid side branch portion BPa.

  The gas side communication pipe Ga constitutes a gas side communication circuit RC3 (gas side communication circuit RC3b) between the outdoor unit 10 and each indoor unit 40, and is a pipe through which a low-pressure refrigerant flows during operation. The gas side communication pipe Ga is configured by connecting a plurality of pipes, joints, and the like. The gas side connecting pipe Ga includes a first gas side connecting pipe G1, a second gas side connecting pipe G2, a third gas side connecting pipe G3, and a branch part BP (gas side branch part BPb). The first gas side connecting pipe G1, the second gas side connecting pipe G2, and the third gas side connecting pipe G3 may actually be constituted by a single pipe or a plurality of joints via joints or the like. You may comprise by connecting piping.

  One end of the first gas side connection pipe G1 is connected to the gas side shutoff valve 20 of the outdoor unit 10, and the outdoor unit is more than the second gas side connection pipe G2, the third gas side connection pipe G3, and the gas side branch portion BPb. 10 side. The second gas side connecting pipe G2 and the third gas side connecting pipe G3 are connected to the indoor unit 40 corresponding to one end. In the present embodiment, the second gas side communication pipe G2 corresponds to the indoor unit 40a, and the third gas side communication pipe G3 corresponds to the indoor unit 40b. The second gas side connecting pipe G2 and the third gas side connecting pipe G3 are arranged in parallel to each other. The first gas side connecting pipe G1, the second gas side connecting pipe G2, and the third gas side connecting pipe G3 are connected and communicated with each other at the gas side branch portion BPb.

  In the following description, one or both of the liquid side communication pipe La and the gas side communication pipe Ga are referred to as “refrigerant communication pipe”. One or both of the first liquid side communication pipe L1 and the first gas side communication pipe G1 are referred to as “one end side connection pipe”. Further, any / all of the second liquid side connecting pipe L2, the third liquid side connecting pipe L3, the second gas side connecting pipe G2, and the third gas side connecting pipe G3 are referred to as “other end side connecting pipe”.

  The branch part BP (liquid side branch part BPa, gas side branch part BPb) included in the refrigerant communication pipe flows from the outdoor unit 10 side (that is, the first liquid side connection pipe L1 or the first gas side connection pipe G1 side). And the indoor unit 40 side (that is, the second liquid side connecting pipe L2 or the third liquid side connecting pipe L3, or the second gas side connecting pipe G2 or the third gas side connecting pipe G3 side). It is the part where the refrigerant flowing from

  Each branch portion BP includes an outdoor unit side connection pipe 81, a plurality of indoor unit side connection pipes 82, a branch pipe 83, and a shut-off valve 84, respectively. In the branch portion BP, the outdoor unit side connection pipe 81 and each indoor unit side connection pipe 82 are connected via the branch pipe 83 and communicated with each other.

  The outdoor unit side connecting pipe 81 (corresponding to “outside pipe” described in the claims) is located closer to the outdoor unit 10 than the branch pipe 83, one end is connected to one end side connecting pipe, and the other end is branched. It is connected to the tube 83.

  Each indoor unit side connecting pipe 82 (corresponding to “indoor side piping” in the claims) is located closer to the indoor unit 40 than the branch pipe 83. Each indoor unit side connecting pipe 82 has a one-to-one correspondence with one of the other end side connecting pipes, and is connected to the corresponding other end side connecting pipe.

  The branch pipe 83 (corresponding to the “branch portion” described in the claims) has one end connected to the outdoor unit side connection pipe 81 and the other end branched in two, and any one of the indoor units at each branch destination. It is connected to the side connection pipe 82.

  The shut-off valve 84 (corresponding to a “control valve” described in the claims) is a valve that allows the flow of the refrigerant when it is opened and shuts off the flow of the refrigerant when it is closed. The shut-off valve 84 is disposed on the outdoor unit side connecting pipe 81. In the present embodiment, the shut-off valve 84 is a valve that can be switched between a closed state and an open state by being supplied with a predetermined drive voltage, and is a commonly used electromagnetic valve. The operation (opening / closing) of the shut-off valve 84 is directly controlled by the electrical component unit 52 and is comprehensively controlled by the controller 70.

  In the air conditioning system 100, the branch portion BP is constituted by the branch pipe unit 50. Specifically, the liquid side branch portion BPa is constituted by the first branch pipe unit 50a, and the gas side branch portion BPb is constituted by the second branch pipe unit 50b. Details of the branch pipe unit 50 will be described later.

(1-4) Refrigerant leakage sensor 60
The refrigerant leakage sensor 60 is a sensor for detecting refrigerant leakage in a target space in which the indoor unit 40 is disposed (more specifically, in the indoor unit 40). In the present embodiment, a known general-purpose product is used for the refrigerant leak sensor 60 in accordance with the type of refrigerant enclosed in the refrigerant circuit RC. The refrigerant leakage sensor 60 is disposed in the target space. More specifically, the refrigerant leakage sensor 60 is associated with the indoor unit 40 on a one-to-one basis, and is disposed in the corresponding indoor unit 40.

  The refrigerant leak sensor 60 outputs an electric signal (refrigerant leak sensor detection signal) corresponding to the detected value to the controller 70 continuously or intermittently. More specifically, the voltage of the refrigerant leak sensor detection signal output from the refrigerant leak sensor 60 changes according to the concentration of the refrigerant detected by the refrigerant leak sensor 60. In other words, the refrigerant leak sensor detection signal includes the refrigerant leak concentration in the target space where the refrigerant leak sensor 60 is installed (more specifically, the refrigerant detected by the refrigerant leak sensor 60 in addition to the presence or absence of refrigerant leak in the refrigerant circuit RC). Is output to the controller 70 in such a manner that it can be specified. That is, the refrigerant leak sensor 60 is a “refrigerant leak detection unit” that detects refrigerant leak in the indoor circuit RC2 by directly detecting the refrigerant flowing out of the indoor circuit RC2 (more specifically, the refrigerant concentration). Equivalent to.

(1-5) Remote control 65
The remote controller 65 is an input device for the user to input various commands for switching the operating state of the air conditioning system 100. For example, the remote controller 65 is input by the user with a command for switching the start / stop of the indoor unit 40, the set temperature, and the like.

  The remote controller 65 also functions as a display device for displaying various information to the user. For example, the remote controller 65 displays the operating state (set temperature, etc.) of the indoor unit 40. Further, for example, when the refrigerant leaks, the remote controller 65 displays information (refrigerant leakage notification information) for notifying the administrator of the fact that the refrigerant is leaking and corresponding processing related thereto.

  The remote controller 65 is connected to the controller 70 (more specifically, the corresponding indoor unit controller 48) via the communication line cb, and transmits and receives signals to and from each other. The remote controller 65 transmits a command input by the user to the controller 70 via the communication line cb. In addition, the remote controller 65 displays information in response to an instruction received via the communication line cb.

(1-6) Controller 70
The controller 70 is a computer that controls the operation of the air conditioning system 100 by controlling the state of each device. In the present embodiment, the controller 70 is configured by connecting the outdoor unit control unit 30 and the indoor unit control unit 48 in each indoor unit 40 via a communication line cb. Details of the controller 70 will be described later.

(2) Flow of refrigerant in refrigerant circuit RC Hereinafter, the flow of refrigerant in the refrigerant circuit RC will be described. In the air conditioning system 100, a forward cycle operation and a reverse cycle operation are mainly performed. Here, the low pressure in the refrigeration cycle is the pressure of refrigerant sucked by the compressor 11 (suction pressure), and the high pressure in the refrigeration cycle is the pressure of refrigerant discharged from the compressor 11 (discharge pressure).

(2-1) Refrigerant flow during forward cycle operation During forward cycle operation (cooling operation, etc.), the four-way switching valve 13 is controlled to the forward cycle state, and the refrigerant charged in the refrigerant circuit RC is mainly the outdoor side. Circuit RC1 (compressor 11, outdoor heat exchanger 14, outdoor first electric valve 16, and subcooler 15), liquid side communication circuit RC3a (first liquid side communication pipe L1, liquid side branch portion BPa, second liquid Side communication pipe L2 and / or third liquid side communication pipe L3), indoor side circuit RC2 (indoor expansion valve 41 and indoor heat exchanger 42) of the indoor unit 40 in operation, gas side communication circuit RC3b (first gas side) The communication pipe G1, the gas side branch portion BPb, the second gas side connection pipe G2 and / or the third gas side connection pipe G3), and the compressor 11 are circulated in this order. During normal cycle operation, in the outdoor circuit RC1, a part of the refrigerant flowing through the sixth pipe P6 branches to the ninth pipe P9 and passes through the outdoor second electric valve 17 and the subcooler 15 (sub-flow path 152). After that, it is returned to the compressor 11.

  Specifically, when the normal cycle operation is started, the refrigerant is sucked into the compressor 11 and compressed after being compressed in the outdoor circuit RC1. In the compressor 11, capacity control is performed according to the thermal load required by the indoor unit 40 during operation. Specifically, the target value of the suction pressure is set according to the thermal load required by the indoor unit 40, and the operating frequency of the compressor 11 is controlled so that the suction pressure becomes the target value. The gas refrigerant discharged from the compressor 11 flows into the outdoor heat exchanger 14.

  The gas refrigerant flowing into the outdoor heat exchanger 14 performs heat exchange with the outdoor air flow sent by the outdoor fan 25 in the outdoor heat exchanger 14 to dissipate heat and condense. The refrigerant flowing out of the outdoor heat exchanger 14 branches in the process of flowing through the sixth pipe P6.

  One refrigerant branched in the process of flowing through the sixth pipe P6 flows into the outdoor first electric valve 16 and is depressurized or adjusted in flow rate according to the opening degree of the outdoor first electric valve 16, and then the subcooler 15 It flows into the main channel 151. The refrigerant that has flowed into the main flow path 151 of the subcooler 15 exchanges heat with the refrigerant flowing through the sub flow path 152 and is further cooled to become a supercooled liquid refrigerant. The liquid refrigerant that has flowed out of the main channel 151 of the subcooler 15 flows out of the outdoor circuit RC1 and flows into the indoor circuit RC2 of the indoor unit 40 that is in operation through the liquid side communication circuit RC3a.

  The other refrigerant branched in the process of flowing through the sixth pipe P6 flows into the outdoor second electric valve 17, and after the pressure is reduced or adjusted in accordance with the opening degree of the outdoor second electric valve 17, the subcooler 15 It flows into the sub flow path 152. The refrigerant flowing into the sub flow path 152 of the subcooler 15 exchanges heat with the refrigerant flowing through the main flow path 151, and then merges with the refrigerant flowing through the first pipe P1 via the eleventh pipe P11.

  The refrigerant that has flowed into the indoor side circuit RC2 of the indoor unit 40 during operation flows into the indoor expansion valve 41, and is depressurized to a low pressure in the refrigeration cycle in accordance with the opening of the indoor expansion valve 41. Flow into the vessel 42.

  The refrigerant that has flowed into the indoor heat exchanger 42 evaporates by exchanging heat with the indoor air flow sent by the indoor fan 45, becomes a gas refrigerant, and flows out of the indoor heat exchanger 42. The gas refrigerant that has flowed out of the indoor heat exchanger 42 flows out of the indoor circuit RC2.

  The refrigerant that has flowed out of the indoor circuit RC2 flows into the outdoor unit 10 through the gas communication circuit RC3b. The refrigerant that has flowed into the outdoor unit 10 flows through the first pipe P1, flows into the accumulator 12 through the four-way switching valve 13 and the second pipe P2. The refrigerant flowing into the accumulator 12 is temporarily stored and then sucked into the compressor 11 again.

(2-2) Flow of refrigerant during reverse cycle operation During reverse cycle operation (heating operation, etc.), the four-way switching valve 13 is controlled to the reverse cycle state, and the refrigerant charged in the refrigerant circuit RC is mainly used as a compressor. 11. Gas side communication circuit RC3b, operating indoor unit 40 (indoor heat exchanger 42 and indoor expansion valve 41), liquid side communication circuit RC3a, supercooler 15, outdoor first electric valve 16, outdoor heat exchanger 14 The compressor 11 is circulated in this order.

  Specifically, when the reverse cycle operation is started, the refrigerant is sucked into the compressor 11 and compressed after being compressed in the outdoor circuit RC1. In the compressor 11, capacity control is performed according to the thermal load required by the indoor unit 40 during operation. The gas refrigerant discharged from the compressor 11 flows out of the outdoor circuit RC1 through the fourth pipe P4 and the first pipe P1, and flows into the indoor circuit RC2 of the operating indoor unit 40 through the gas communication circuit RC3b. To do.

  The refrigerant that has flowed into the indoor circuit RC2 flows into the indoor heat exchanger 42, and is condensed by exchanging heat with the indoor airflow sent by the indoor fan 45. The refrigerant that has flowed out of the indoor heat exchanger 42 flows into the indoor expansion valve 41, is decompressed to a low pressure in the refrigeration cycle according to the opening of the indoor expansion valve 41, and then flows out of the indoor circuit RC <b> 2.

  The refrigerant that has flowed out of the indoor circuit RC2 flows into the outdoor circuit RC1 through the liquid side communication circuit RC3a. The refrigerant flowing into the outdoor circuit RC1 passes through the eighth pipe P8, the supercooler 15 (main flow path 151), the seventh pipe P7, the outdoor first electric valve 16 and the sixth pipe P6, and then the outdoor heat exchanger 14. Flows into the liquid side inlet / outlet.

  The refrigerant flowing into the outdoor heat exchanger 14 evaporates by exchanging heat with the outdoor air flow sent by the outdoor fan 25 in the outdoor heat exchanger 14. The refrigerant flowing out from the gas side inlet / outlet of the outdoor heat exchanger 14 flows into the accumulator 12 through the fifth pipe P5, the four-way switching valve 13, and the second pipe P2. The refrigerant flowing into the accumulator 12 is temporarily stored and then sucked into the compressor 11 again.

(3) Details of the branch pipe unit 50 The branch pipe unit 50 is a unit for constituting a branch portion BP (corresponding to a “first portion” described in claims) in the communication circuit RC3. Further, the branch pipe unit 50 has a refrigerant flow (mainly from the outdoor circuit RC1 side) between the outdoor circuit RC1 and the indoor circuit RC2 when refrigerant leakage occurs in the refrigerant circuit RC (particularly the indoor circuit RC2). It is also a unit for constituting a blocking part that blocks the flow of the refrigerant toward the indoor circuit RC2 side.

  In the refrigerant circuit RC, as the branch pipe unit 50, a first branch pipe unit 50a arranged in the liquid side connection circuit RC3a and a second branch pipe unit 50b arranged in the gas side communication circuit RC3b are arranged. Yes.

  The first branch pipe unit 50a is included in the liquid side communication pipe La. The first branch pipe unit 50a is disposed between the first liquid side connecting pipe L1, the second liquid side connecting pipe L2, and the third liquid side connecting pipe L3, and connects the two. That is, the first branch pipe unit 50a includes a first liquid side connecting pipe L1 arranged on the outdoor unit 10 side, a second liquid side connecting pipe L2 and a third liquid side connecting pipe L3 arranged on the indoor unit 40 side. And connect. The first branch pipe unit 50a constitutes a branch portion BP (liquid side branch portion BPa) in the liquid side communication circuit RC3a. The first branch pipe unit 50a includes a refrigerant flowing from the outdoor unit 10 side to the indoor unit 40 side through the first liquid side connecting pipe L1, the second liquid side connecting pipe L2, and the third liquid side connecting pipe L3, and the second A refrigerant flow path common to both the refrigerant flowing from the indoor unit 40 to the outdoor unit 10 through the liquid side communication pipe L2, the third liquid side connection pipe L3, and the first liquid side connection pipe L1 is formed.

  The second branch pipe unit 50b is included in the gas side communication pipe Ga. The second branch pipe unit 50b is arranged between the first gas side communication pipe G1, the second gas side connection pipe G2, and the third gas side connection pipe G3, and connects the two. That is, the second branch pipe unit 50b includes a first gas side communication pipe G1 disposed on the outdoor unit 10 side, a second gas side communication pipe G2 and a third gas side communication pipe G3 disposed on the indoor unit 40 side. And connect. The second branch pipe unit 50b constitutes a branch portion BP (gas side branch portion BPb) in the gas side communication circuit RC3b. The second branch pipe unit 50b includes a refrigerant flowing from the outdoor unit 10 side to the indoor unit 40 side through the first gas side communication pipe G1, the second gas side connection pipe G2, and the third gas side connection pipe G3, and the second A refrigerant flow path common to both the refrigerant flowing from the indoor unit 40 to the outdoor unit 10 through the gas side communication pipe G2, the third gas side connection pipe G3, and the first gas side communication pipe G1 is formed.

  Hereinafter, a detailed configuration of the branch pipe unit 50 will be described. In the following description, “joining” of each part is appropriately selected as “joining method” according to the installation environment and design specifications. The “joining method” is not particularly limited, and for example, brazing connection, flare connection, flange connection, or the like is assumed. Further, the following description is common to the first branch pipe unit 50a and the second branch pipe unit 50b unless otherwise specified.

  FIG. 2 is a schematic configuration diagram of the main unit 51. FIG. 3 is a schematic diagram illustrating an example of an installation mode of the branch pipe unit 50. The branch pipe unit 50 mainly includes a main body unit 51, an electrical component unit 52 and an electric wire 53.

(3-1) Main unit 51
The main unit 51 is a part of the branch pipe unit 50 that constitutes the communication circuit RC3 and forms the refrigerant flow path (branch part BP). The main unit 51 is carried into the construction site in a state assembled in advance at a factory or the like, and is connected to other piping. The main unit 51 includes the above-described outdoor unit side connection pipe 81, a plurality (here, two) of indoor unit side connection pipes 82, a branch pipe 83, and a shut-off valve 84. The outdoor unit side connection pipe 81, each indoor unit side connection pipe 82, the branch pipe 83, and the cutoff valve 84 are integrally configured in the main body unit 51.

(3-1-1) Outdoor unit side connection pipe 81
The outdoor unit side connecting pipe 81 is a tubular portion extending along a predetermined extending direction (x direction in FIG. 3). The outdoor unit side connecting pipe 81 communicates with the one end side connecting pipe to form a refrigerant flow path. The outdoor unit side connecting pipe 81 has one end (end on the one end side connecting pipe side) joined to the shut-off valve 84 and the other end (end on the other end side connecting pipe side) joined to the branch pipe 83. Yes.

  The outdoor unit side connecting pipe 81 is connected to the outdoor unit 10 from the indoor unit 40 via the indoor unit side connecting pipe 82 and the refrigerant flowing from the outdoor unit 10 side to the indoor unit 40 side via the indoor unit side connecting pipe 82 in the communication circuit RC3. A common refrigerant flow path is formed for both the refrigerant flowing into the refrigerant.

  In the present embodiment, the outdoor unit side connecting pipe 81 is made of the same copper as the one end side connecting pipe. In addition, about the cross-sectional area and length dimension of the outdoor unit side connection pipe 81, it selects suitably according to design specifications (for example, the diameter of the one end side connection piping connected, etc.) and installation environment.

(3-1-2) Indoor unit side connecting pipe 82
Each indoor unit side connecting pipe 82 is a tubular portion extending substantially parallel to the other indoor unit side connecting pipe 82. Here, “substantially parallel” means not only the case where each indoor unit side connecting pipe 82 is completely parallel, but also the extension direction of each indoor unit side connecting pipe 82 is slightly (for example, 30 degrees horizontally or vertically). Including the case where it is different. The same applies to other parts in this specification.

  Each indoor unit side connecting pipe 82 is associated with one of the other end side connecting pipes on a one-to-one basis, and communicates with the corresponding other end side connecting pipe to form a refrigerant flow path. The longitudinal direction (extending direction) of each indoor unit side connecting pipe 82 extends in the opposite direction to the outdoor unit side connecting pipe 81 along the same direction as the longitudinal direction (extending direction) of the outdoor unit side connecting pipe 81. ing. Here, “substantially the same” means not only when the longitudinal direction of the indoor unit side connecting pipe 82 and the longitudinal direction of the outdoor unit side connecting pipe 81 completely coincide, but also slightly (for example, in the horizontal direction or the vertical direction). (Including within 30 degrees). The same applies to other parts in this specification.

  The indoor unit side connecting pipe 82 has one end (end on the one end side connecting pipe side) joined to the branch pipe 83 and the other end joined to the corresponding other end side connecting pipe. In this embodiment, the indoor unit side connecting pipe 82 is made of the same copper as the corresponding other end side connecting pipe. In addition, about the cross-sectional area and length dimension of each indoor unit side connection pipe 82, it selects individually according to design specifications (for example, diameter of the other end side connection piping etc.) and installation environment.

(3-1-3) Branch pipe 83
The branch pipe 83 is located between the outdoor unit side connecting pipe 81 and each indoor unit side connecting pipe 82 and connects the two. The branch pipe 83 allows the outdoor unit side connecting pipe 81 and the corresponding indoor unit side connecting pipes 82 to communicate with each other individually. The branch pipe 83 branches the refrigerant flowing from the outdoor unit side connecting pipe 81 side and sends it to each indoor unit side connecting pipe 82, or joins the refrigerant flowing from each indoor unit side connecting pipe 82 side to the outdoor unit side This corresponds to a junction that is sent to the connecting pipe 81.

  The branch pipe 83 is connected to the branch pipe body 830, the first insertion part 831 to which the outdoor unit side connection pipe 81 is joined, and a plurality of (indoor unit side connection pipes) to which the corresponding indoor unit side connection pipes 82 are joined. Number of second insertion portions 832).

  The branch pipe body 830 is a substantially U-shaped (bifurcated) tubular portion. The first insertion part 831 extends along the extending direction of the outdoor unit side connecting pipe 81 from the portion between both ends of the branch pipe main body part 830, and is formed with a communication port communicating with the outdoor unit side connecting pipe 81. Yes. The second insertion part 832 extends from one end or the other end of the branch pipe main body part 830 along the extending direction with the corresponding indoor unit side connection pipe 82, and communicates with the corresponding indoor unit side connection pipe 82. A communication port is formed.

  In the present embodiment, the branch pipe 83 is made of the same copper as the outdoor unit side connecting pipe 81 and the indoor unit side connecting pipe 82 to be connected. In addition, about the cross-sectional area and length dimension of the branch pipe 83 (a main-body part, the 1st insertion part 831, each 2nd insertion part 832), it is a design specification (For example, the diameter of the other end side connection piping connected, etc.) ) Or depending on the installation environment.

(3-1-4) Shut-off valve 84
The shutoff valve 84 is located between the outdoor unit side connecting pipe 81 and the one end side connecting pipe, and switches the flow of the refrigerant. The outdoor unit side connecting pipe 81 is connected to the end of the one end side connecting pipe side. From another viewpoint, it can be said that the shut-off valve 84 is disposed on the outdoor unit side connecting pipe 81.

  The shutoff valve 84 mainly includes a valve main body 840, a first pipe connection part 841, and a second pipe connection part 842.

  The valve main body 840 is a main body portion of the shutoff valve 84 and includes a valve body, a coil, and the like. Inside the valve body 840, there is formed a refrigerant flow path 840a that allows the first pipe connection portion 841 and the second pipe connection portion 842 to communicate with each other. By closing the path 840a, the closed state is established. In FIG. 2, the position of the valve body N1 in the closed state is schematically shown. As shown in FIG. 2, in the shut-off valve 84, the valve element N1 extends along the z direction (the same direction as the extending direction of the first pipe connecting portion 841). In the present embodiment, the shut-off valve 84 has a substantially L-shaped appearance, and the refrigerant flow path 840a formed therein also has a substantially L-shape.

  The first pipe connection portion 841 is a tubular portion extending from the side portion of the valve main body portion 840 along a predetermined extending direction (z direction in FIG. 2). The first pipe connection portion 841 communicates with one end of the refrigerant flow path 840a in the valve main body portion 840. One end of the first pipe connection portion 841 is joined to the side portion of the valve main body portion 840. The other end of the first pipe connecting portion 841 is joined to the one end side connecting pipe in the installed state.

  The second pipe connection portion 842 is a tubular portion extending from the bottom portion of the valve main body portion 840 along a predetermined extending direction (the x direction in FIG. 2). As described above, the shut-off valve 84 has a substantially L-shaped appearance, and the refrigerant flow path 840a formed therein also has a substantially L-shape. In this regard, the extending direction (longitudinal direction) of the second pipe connecting portion 842 and the extending direction (longitudinal direction) of the first pipe connecting portion 841 are different and intersecting directions. More specifically, the extending direction of the second pipe connecting part 842 is different from the extending direction of the first pipe connecting part 841 by approximately 90 degrees. In this regard, during normal cycle operation, the refrigerant flows from the first pipe connection portion 841 to the second pipe connection portion 842, but the valve body N1 extends along the same direction as the first pipe connection portion 841. For this reason, noise reduction when the shut-off valve 84 is controlled to be closed is promoted.

  Here, “substantially 90 degrees” is not only the case where the extending direction of the second pipe connecting portion 842 and the extending direction of the first pipe connecting portion 841 are completely different by 90 degrees, but also from 90 degrees to a predetermined range. (Including within 30 degrees).

  The second pipe connection portion 842 communicates with the other end of the refrigerant flow path 840a in the valve body portion 840. One end of the second pipe connection part 842 is joined to the bottom part of the valve main body part 840. The other end of the second pipe connection part 842 is joined to the other end of the outdoor unit side connection pipe 81 (an end part on the one end side connection pipe side). More specifically, in the second pipe connection portion 842, in the installed state, the indoor unit side connection pipes 82 are arranged along the horizontal direction, and the longitudinal direction of the indoor unit side connection pipes 82 extends along the horizontal direction. Is connected to the other end of the outdoor unit side connecting pipe 81.

(3-2) Electrical component unit 52
The electrical component unit 52 (see FIG. 3) is provided independently of the main unit 51 so as to be freely movable with respect to the main unit 51 at the construction site and to improve workability. The electrical component unit 52 is fixed by a fixture 90 (see FIG. 3) at the construction site.

  The electrical component unit 52 includes an electrical component 521 for controlling the state (opening / closing) of the shutoff valve 84 (for example, a switching unit capable of switching a current flow such as an electromagnetic relay or a switching element, a connection terminal to which power is supplied, And an input unit for inputting a signal from the controller 70. Further, the electrical component unit 52 has a substrate 522 for mounting the electrical component 521.

  Further, the electrical component unit 52 includes a unit casing 523 that accommodates the electrical component 521, the substrate 522, and the like. The unit casing 523 is a casing made of synthetic resin, for example, and has a volume that can accommodate the electrical component 521, the substrate 522, and the like. The unit casing 523 is provided with a fixing portion 524 for fixing the fixture 90. Since the unit casing 523 is assumed to be installed in a narrow space, the height dimension is configured to be smaller than the height dimension of the installation place (general ceiling space).

(3-3) Electric wire 53
The electric wire 53 (see FIG. 3) is a conducting wire for supplying a drive voltage to the shut-off valve 84. The electric wire 53 electrically connects the shut-off valve 84 and the substrate 522 (electrical component 521). The electric wire 53 is a general general-purpose product and is covered with an insulator.

  The electric wire 53 is configured to have a dimension of 1 m or more so as to increase the degree of freedom regarding the arrangement of the electrical component unit 52 at the installation location. In the present embodiment, the longitudinal dimension of the electric wire 53 is 1.2 m.

(3-4) Installation Mode of Branch Pipe Unit 50 In FIG. 3, the branch pipe unit 50 is shown installed in the ceiling space SP (the space behind the ceiling of the target space). In FIG. 3, the directions of up, down, left, and right are shown. The left-right direction corresponds to the x direction in FIG. 2, and the up-down direction corresponds to the y direction in FIG. Here, the horizontal direction is included in the horizontal direction, and the vertical direction is included in the vertical direction. In FIG. 3, the front-rear direction orthogonal to the left-right direction corresponds to the z direction in FIG. 2 and is included in the horizontal direction.

  The branch pipe unit 50 is installed together with the refrigerant communication pipe in the ceiling back space SP. The ceiling back space SP is a narrow space formed between the upper surface of the ceiling of the target space (ceiling back bottom surface C1) and the roof or the upper floor (ceiling back top surface C2). Specifically, the ceiling space SP is a space having a large horizontal dimension and a small vertical dimension.

  In the present embodiment, the main unit 51 includes the indoor unit side connecting pipes 82 arranged in the horizontal direction (here, the z direction intersecting the extending direction x), and the extending direction of each indoor unit side connecting pipe 82 and the outdoor unit side. The connecting pipe 81 is arranged in such a posture that it matches the extending direction (here, both directions are different, but both extending directions are horizontal directions). In this connection, in the ceiling space SP, the main extending direction of the other end side connecting pipe (here, the horizontal direction, that is, the horizontal direction) and the main extending direction of the one end side connecting pipe (here, the left and right direction, that is, the horizontal direction). Are substantially the same. In other words, in the ceiling space SP having a narrow vertical length, the main unit 51 includes the main extending direction of the other end side connecting pipe (here, the horizontal direction, that is, the horizontal direction) and the main extending direction of the one end side connecting pipe ( Here, they are arranged in such a posture that the left and right direction, that is, the horizontal direction) is substantially the same.

  It should be noted that this is the connection mode between the first pipe connection part 841 and the second pipe connection part 842 of the shut-off valve 84 and the outdoor unit side connection pipe 81 and each indoor unit side connection pipe 82 (in the installed state, each indoor unit side A posture in which the connecting pipes 82 are arranged along the horizontal direction and the longitudinal direction of the outdoor unit side connecting pipe 81 and each indoor unit side connecting pipe 82 can extend along the horizontal direction, that is, the first pipe of the shut-off valve 84 Realized by connecting the second pipe connecting portion 842 to the other end of the outdoor unit side connecting pipe 81 in such a posture that the connecting portion 841 extends in the front-rear direction and the second pipe connecting portion 842 extends in the left-right direction. It is possible.

  The one end side connecting pipe extends along the main extending direction (the x direction in FIG. 3) of the other end side connecting pipe, and then is in front of the connection portion with the main unit 51 (the first pipe connecting portion 841 of the shut-off valve 84). And curved toward the first pipe connection portion 841 direction (z direction) of the shutoff valve 84 and joined to the main unit 51.

  Each part of the main unit 51 (the outdoor unit side connecting pipe 81, the indoor unit side connecting pipe 82, the branch pipe 83 and the shutoff valve 84) is covered with a heat insulating material 95 for preventing condensation.

  The electrical component unit 52 is installed apart from the main unit 51. More specifically, the electrical component unit 52 is set apart from the main unit 51 within the range of the length dimension of the electric wire 53 that electrically connects the main unit 51 and the electrical component unit 52. In the present embodiment, the electrical component unit 52 is suspended from the ceiling space SP by attaching the fixture 90 fixed to the ceiling top surface C2.

  The electrical component unit 52 extends between the shut-off valve 84 of the main unit 51 and the substrate 522 (electrical component 521) of the electrical component unit 52, and electrically connects both. The electric wire 53 is connected in advance to one of the shut-off valve 84 and the main unit 51 before being installed, and is connected to the other at the site.

(4) Details of Controller 70 In the air conditioning system 100, the outdoor unit control unit 30 and the indoor unit control unit 48 are connected by the communication line cb, so that the controller 70 is configured. FIG. 4 is a block diagram schematically showing the controller 70 and each unit connected to the controller 70.

  The controller 70 has a plurality of control modes, and controls the operation of each device according to the transition control mode. In the present embodiment, the controller 70 has, as control modes, a normal operation mode that transitions during operation (when there is no refrigerant leakage) and a case where refrigerant leakage occurs (more specifically, when a leaked refrigerant is detected). And a refrigerant leakage mode that makes a transition to ().

  The controller 70 includes devices included in the air conditioning system 100 (specifically, the compressor 11, the outdoor first electric valve 16, the outdoor second electric valve 17, the outdoor fan 25, and the outdoor sensor 26 included in the outdoor unit 10). The indoor expansion valve 41, the indoor fan 45 and the indoor side sensor 46 included in each indoor unit 40, the electrical component 521 (shutoff valve 84) of each branch pipe unit 50, each refrigerant leak sensor 60, each remote controller 65, etc. ) And are electrically connected.

  The controller 70 mainly includes a storage unit 71, an input control unit 72, a mode control unit 73, a refrigerant leakage determination unit 74, a device control unit 75, a drive signal output unit 76, and a display control unit 77. Have. Each of these functional units in the controller 70 is realized by the CPU, the memory, and various electric / electronic components included in the outdoor unit control unit 30 and / or the indoor unit control unit 48 functioning integrally. Yes.

(4-1) Storage unit 71
The storage unit 71 includes, for example, a ROM, a RAM, and a flash memory, and includes a volatile storage area and a nonvolatile storage area. The storage unit 71 includes a program storage area M1 in which a control program that defines processing in each unit of the controller 70 is stored.

  The storage unit 71 includes a detection value storage area M2 for storing detection values of various sensors. In the detection value storage area M2, for example, the detection values (intake pressure, discharge pressure, discharge temperature, refrigerant temperature in the outdoor heat exchanger 14, or indoor heat exchanger 42 in the indoor heat exchanger 42) are detected by the outdoor sensor 26 and the indoor sensor 46. Refrigerant temperature etc.) is stored.

  In addition, the storage unit 71 includes a sensor signal storage area M3 for storing a refrigerant leak sensor detection signal (a detection value of the refrigerant leak sensor 60) transmitted from the refrigerant leak sensor 60. The sensor signal storage area M3 has storage areas corresponding to the number of refrigerant leakage sensors 60, and the received refrigerant leakage sensor detection signal is stored in an area corresponding to the transmission source refrigerant leakage sensor 60. The refrigerant leakage signal stored in the sensor signal storage area M3 is updated every time the refrigerant leakage signal output from the refrigerant leakage sensor 60 is received.

  In addition, the storage unit 71 includes a command storage area M4 for storing commands input to the remote controllers 65.

  The storage unit 71 is provided with a plurality of flags having a predetermined number of bits. For example, the storage unit 71 is provided with a control mode determination flag M5 that can determine the control mode in which the controller 70 is changing. The control mode determination flag M5 includes the number of bits corresponding to the number of control modes, and can be set with a bit corresponding to the transitioned control mode.

  Further, the storage unit 71 is provided with a refrigerant leak detection flag M6 for determining that a refrigerant leak in the target space has been detected. More specifically, the refrigerant leak detection flag M6 has a number of bits corresponding to the number of indoor units 40 installed, and corresponds to the indoor unit 40 (refrigerant leak unit) where refrigerant leak is assumed to have occurred. A bit can be set. That is, the refrigerant leakage detection flag M6 is configured to be able to determine which indoor unit 40 (indoor side circuit RC2) has the refrigerant leakage when the refrigerant leakage occurs in the indoor side circuit RC2. The refrigerant leakage detection flag M6 is switched by the refrigerant leakage determination unit 74.

(4-2) Input control unit 72
The input control unit 72 is a functional unit that serves as an interface for receiving signals output from each device connected to the controller 70. For example, the input control unit 72 receives signals output from the sensors (26, 46, 60) and the remote controller 65 and stores them in the corresponding storage area of the storage unit 71 or sets a predetermined flag.

(4-3) Mode control unit 73
The mode control unit 73 is a functional unit that switches the control mode. The mode control unit 73 switches the control mode to the normal operation mode at the normal time (when the refrigerant leakage detection flag M6 is not set). The mode control unit 73 switches the control mode to the refrigerant leakage mode when the refrigerant leakage detection flag M6 is set. The mode control unit 73 sets a control mode determination flag M5 in accordance with the transition control mode.

(4-4) Refrigerant leakage determination unit 74
The refrigerant leakage determination unit 74 is a functional unit that determines whether or not refrigerant leakage has occurred in the refrigerant circuit RC (indoor circuit RC2). Specifically, the refrigerant leakage determination unit 74 determines that refrigerant leakage has occurred in the refrigerant circuit RC (indoor circuit RC2) when a predetermined refrigerant leakage detection condition is satisfied, and sets the refrigerant leakage detection flag M6. .

  In the present embodiment, whether or not the refrigerant leak detection condition is satisfied is determined based on the refrigerant leak sensor detection signal in the sensor signal storage area M3. Specifically, the refrigerant leak detection condition is that a time during which a voltage value (detection value of the refrigerant leak sensor 60) related to any one of the refrigerant leak sensor detection signals is equal to or greater than a predetermined first reference value continues for a predetermined time t1 or more. Filled by. The first reference value is a value (refrigerant concentration) at which refrigerant leakage is assumed in the indoor circuit RC2. The predetermined time t1 is set to a time during which it can be determined that the refrigerant leakage sensor detection signal is not instantaneous. The refrigerant leakage determination unit 74 identifies a refrigerant leakage unit (the indoor unit 40 in which refrigerant leakage is assumed to occur) based on the refrigerant leakage sensor 60 that is the transmission source of the refrigerant leakage sensor detection signal that satisfies the refrigerant leakage detection condition. The bit corresponding to the refrigerant leakage unit is set in the refrigerant leakage detection flag M6. That is, the refrigerant leakage determination unit 74 corresponds to a “refrigerant leakage detection unit” that individually detects refrigerant leakage of each indoor circuit RC2 together with each refrigerant leakage sensor 60.

  The predetermined time t1 is appropriately set according to the type of refrigerant sealed in the refrigerant circuit RC, the specifications of each device, the installation environment, etc., and is defined in the control program. The refrigerant leakage determination unit 74 is configured to be able to measure the predetermined time t1.

  The first reference value is appropriately set according to the type, design specifications, installation environment, and the like of the refrigerant sealed in the refrigerant circuit RC, and is defined in the control program.

(4-5) Device control unit 75
The device control unit 75 controls the operation of each device (for example, 11, 13, 16, 17, 25, 41, 45, 84, etc.) included in the air conditioning system 100 according to the situation according to the control program. The device control unit 75 determines the control mode that has transitioned by referring to the control mode determination flag M5, and controls the operation of each device based on the determined control mode.

  For example, in the normal operation mode, the device control unit 75 operates the compressor 11, the outdoor fan 25, and the indoor so that the normal cycle operation or the reverse cycle operation is performed according to the set temperature, the detection value of each sensor, or the like. The rotation speed of the fan 45, the opening degree of the outdoor first electric valve 16, the opening degree of the indoor expansion valve 41, and the like are controlled in real time.

  The device control unit 75 controls the four-way switching valve 13 to the normal cycle state during the normal cycle operation, causes the outdoor heat exchanger 14 to function as a refrigerant condenser (or a radiator), and the indoor unit 40 in operation. The indoor heat exchanger 42 is caused to function as a refrigerant evaporator. In addition, during reverse cycle operation, the device control unit 75 controls the four-way switching valve 13 to be in a reverse cycle state, causing the outdoor heat exchanger 14 to function as a refrigerant evaporator and exchanging indoor heat in the indoor unit 40 during operation. The vessel 42 is caused to function as a refrigerant condenser (or radiator).

  In addition, the device control unit 75 executes the following various controls depending on the situation. The device controller 75 is configured to be able to measure time.

<Refrigerant leakage first control>
When it is assumed that refrigerant leakage has occurred in the target space (specifically, when the refrigerant leakage detection flag M6 is set), the device control unit 75 executes the first refrigerant leakage control. In the refrigerant leakage first control, the device control unit 75 controls the indoor expansion valve 41 of the refrigerant leakage unit (the indoor unit 40 in which the refrigerant leakage has occurred) to be closed. Thereby, the inflow of the refrigerant to the refrigerant leakage unit is suppressed, and further refrigerant leakage is suppressed. That is, the refrigerant leakage first control is control for suppressing refrigerant leakage in the indoor circuit RC2 when refrigerant leakage occurs, and the indoor expansion valve 41 is in a closed state when refrigerant leakage occurs. The refrigerant flowing into the indoor unit 40 is obstructed.

<Refrigerant leakage second control>
The device control unit 75 executes the refrigerant leakage second control when it is assumed that the refrigerant leakage has occurred in the target space. The device control unit 75 operates the indoor fans 45 of the indoor units 40 at the rotation speed (air flow rate) for the refrigerant leakage second control in the refrigerant leakage second control. The refrigerant leakage second control is a control for operating the indoor fan 45 at a predetermined rotational speed in order to prevent a region where the concentration of the leakage refrigerant is high in the target space from occurring locally.

  In addition, although the rotation speed of the indoor fan 45 in the refrigerant | coolant leakage 2nd control which concerns is not specifically limited, In this embodiment, it sets to the maximum rotation speed (namely, maximum airflow). Even if the refrigerant leakage occurs in the target space by the refrigerant leakage second control, the leakage refrigerant is agitated in the target space by the use-side air flow generated by the indoor fan 45 and leaked in the target space. Occurrence of a region having a dangerous value of the refrigerant concentration is suppressed.

<Refrigerant leakage third control>
When it is assumed that the refrigerant leakage has occurred in the target space, the device control unit 75 executes the third refrigerant leakage control. In the refrigerant leakage third control, the device control unit 75 controls the shut-off valve 84 of each branch portion BP to be closed in order to divide the outdoor circuit RC1 and each indoor circuit RC2. That is, the third refrigerant leakage control is a control in which, when refrigerant leakage occurs, the refrigerant flowing from the outdoor circuit RC1 to the indoor circuit RC2 of the leakage unit is blocked by the liquid side communication circuit RC3a and the gas side communication circuit RC3b. is there.

  Specifically, the device control unit 75 closes the liquid side communication circuit RC3a by controlling the shut-off valve 84 of the liquid side branch portion BPa to the closed state via the electric component 521 in the third refrigerant leakage control. In addition, in the third refrigerant leakage control, the device control unit 75 controls the shut-off valve 84 of the gas side branch portion BPb to be closed via the electrical component 521, thereby closing the gas side communication circuit RC3b. Thereby, the flow of the refrigerant from the outdoor circuit RC1 to the indoor circuit RC2 is blocked by the communication circuit RC3, and the leakage refrigerant amount in the indoor circuit RC2 is reliably suppressed.

(4-6) Drive signal output unit 76
The drive signal output unit 76 corresponds to each device (11, 13, 16, 17, 25, 41, 45, 521 (84), etc.) according to the control content of the device control unit 75. Voltage). The drive signal output unit 76 includes a plurality of inverters (not shown), and a specific device (for example, the compressor 11, the outdoor fan 25, or each indoor fan 45) is driven from the corresponding inverter. Output a signal.

(4-7) Display control unit 77
The display control unit 77 is a functional unit that controls the operation of the remote controller 65 as a display device. The display control unit 77 causes the remote controller 65 to output predetermined information in order to display information related to the driving state and situation to the user. For example, the display control unit 77 causes the remote controller 65 to display various information such as a set temperature during operation in the normal mode.

  Further, when the refrigerant leak detection flag M6 is set, the display control unit 77 causes the remote controller 65 to display the refrigerant leak notification information. Thereby, the administrator can grasp the fact that the refrigerant leakage has occurred, and can take a predetermined response.

(5) Process Flow of Controller 70 An example of the process flow of the controller 70 will be described below with reference to FIG. FIG. 5 is a flowchart showing an example of the processing flow of the controller 70. When the controller 70 is turned on, the controller 70 performs processing in a flow as shown in steps S101 to S110 in FIG. The process flow shown in FIG. 5 is an example and can be changed as appropriate. For example, the order of steps may be changed within a consistent range, some steps may be executed in parallel with other steps, and other steps may be newly added.

  In step S101, the controller 70 proceeds to step S105 when it is assumed that refrigerant leakage has occurred in the indoor circuit RC2 (that is, in the case of YES). If it is assumed that no refrigerant leakage has occurred in the indoor circuit RC2, the controller 70 proceeds to step S102.

  In step S102, the controller 70 returns to step S101 when the operation start command is not input (that is, in the case of NO). On the other hand, when the operation start command is input (that is, in the case of YES), the controller 70 proceeds to step S103.

  In step S103, the controller 70 transitions to the normal operation mode (or maintains the normal operation mode). Thereafter, the process proceeds to step S104.

  In step S104, the controller 70 performs the normal cycle operation by controlling the state of each device in real time according to the input command, the set temperature, the detection value of each sensor (26, 46), and the like. . Although not shown, the controller 70 causes the remote controller 65 to display various information such as a set temperature. Then, it returns to step S101.

  In step S105, the controller 70 transitions to the refrigerant leakage mode. Thereafter, the controller 70 proceeds to step S106.

  In step S106, the controller 70 causes the remote controller 65 to output refrigerant leakage notification information. Thereby, the administrator can grasp that the refrigerant leakage has occurred. Thereafter, the controller 70 proceeds to step S107.

  In step S107, the controller 70 executes the refrigerant leakage first control. Specifically, the controller 70 controls the indoor expansion valve 41 of the refrigerant leakage unit to be closed. Thereby, the flow of the refrigerant | coolant to the indoor side circuit RC2 of a refrigerant | coolant leakage unit is prevented, and further refrigerant | coolant leakage is suppressed. Thereafter, the controller 70 proceeds to step S108.

  In step S108, the controller 70 executes the refrigerant leakage second control. Specifically, the controller 70 drives the indoor fan 45 at a predetermined rotation speed (for example, the maximum rotation speed). Thereby, in the target space, the leaked refrigerant is agitated, and a locally dangerous concentration is suppressed. Thereafter, the controller 70 proceeds to step S109.

  In step S109, the controller 70 executes the refrigerant leakage third control. Specifically, the controller 70 closes the shutoff valve 84 of the liquid side branch portion BPa to close the liquid side communication circuit RC3a. In addition, in the third refrigerant leakage control, the device control unit 75 closes the gas side communication circuit RC3b by controlling the shutoff valve 84 of the gas side branch portion BPb to be closed. Thereby, it is suppressed that a refrigerant | coolant flows from the outdoor side circuit RC1 to the indoor side circuit RC2 of a leakage unit, and the amount of leakage refrigerant is suppressed. Thereafter, the controller 70 proceeds to step S110.

  In step S110, the controller 70 stops the compressor 11. Thereafter, the controller 70 waits until it is released by the administrator.

(6) Features (6-1)
In the air conditioning system 100 according to the above embodiment, the shutoff valve 84 that blocks the flow of the refrigerant to the plurality of indoor units 40 is disposed on the outdoor unit side connection pipe 81 (outdoor pipe), and the number of indoor units 40 is Accordingly, the increase in the number of shut-off valves 84 is suppressed. In other words, the shutoff valve 84 is arranged on the outdoor unit 10 side of each indoor unit side connecting pipe 82 (indoor side piping group) in the branch portion BP, so that when the refrigerant leaks, the outdoor unit side connecting pipe 81 (outdoor unit 10). It is possible to prevent the flow of the refrigerant flowing from the corresponding side to the corresponding indoor unit side connecting pipe 82 (the plurality of indoor units 40). For this reason, in order to ensure the safety | security regarding a refrigerant | coolant leakage, it is not necessary to arrange | position the shut-off valve 84 for every indoor unit 40, and it is suppressed that the number of the shut-off valves 84 increases according to the number of indoor units 40. .

  In addition, the refrigerant communication pipes (La, Ga) between the outdoor unit 10 and the indoor unit 40 are constructed in a narrow ceiling space SP, so that the number of shut-off valves 84 installed on the refrigerant communication pipe increases. Therefore, the increase in work time and labor required for construction is also suppressed.

  Therefore, in connection with improving the security against refrigerant leakage, cost reduction and workability improvement are promoted.

(6-2)
In the air conditioning system 100 according to the embodiment, the refrigerant communication pipe (La, Ga) includes a gas side communication pipe Ga through which a low-pressure refrigerant flows and a liquid side communication pipe La through which a high-pressure or intermediate-pressure refrigerant flows. The shutoff valve 84 is disposed on the outdoor unit side connection pipe 81 (outdoor pipe) included in the gas side communication pipe Ga.

  Here, in the outdoor unit 10 or the indoor unit 40, it is normal that an indoor expansion valve 41 (electronic expansion valve) for reducing the pressure of the refrigerant is disposed on the refrigerant flow path communicating with the liquid side communication pipe La. When the refrigerant leaks, it is possible to prevent the flow of the refrigerant flowing from the outdoor unit 10 to the indoor unit 40 via the liquid side connection pipe La by controlling the indoor expansion valve 41 to the minimum opening. On the other hand, since there are many cases in which a control valve similar to the indoor expansion valve 41 is not disposed on the refrigerant flow path communicating with the gas side communication pipe Ga, in order to ensure safety against refrigerant leakage, It is important to prevent the flow of the refrigerant toward the indoor unit 40 side.

  In the air conditioning system 100, the shutoff valve 84 is arranged on the outdoor unit side connecting pipe 81 included in the gas side communication pipe Ga, so that an increase in the number of shutoff valves 84 is suppressed, and security against refrigerant leakage is suppressed. Ensuring is promoted.

(6-3)
In the air conditioning system 100 according to the above embodiment, the shutoff valve 84 is also disposed on the outdoor unit side connection pipe 81 (outdoor pipe) included in the liquid side communication pipe La. Thus, the safety | security ensuring with respect to a refrigerant | coolant leakage is promoted especially by arrange | positioning the shut-off valve 84 also on the outdoor unit side connection pipe 81 (outdoor pipe) included in the liquid side connection pipe La.

(6-4)
In the air conditioning system 100 according to the above-described embodiment, the indoor unit 40 includes the indoor expansion valve 41, and when refrigerant leakage occurs, the indoor unit 40 is in a closed state to prevent the refrigerant flowing into the indoor unit 40. In this way, the indoor expansion valve 41 that prevents the flow of the refrigerant by being controlled to be closed when the refrigerant leakage occurs is arranged in the indoor unit 40, so that the outdoor unit 10 to the indoor unit 40 at the time of the refrigerant leakage. It is possible to cut off the flow of the refrigerant more reliably.

(6-5)
In the air conditioning system 100 according to the embodiment, the outdoor unit side connecting pipe 81 (outdoor pipe) is configured integrally with the branch pipe 83 (branch portion) and the shutoff valve 84. Thereby, installation of the shut-off valve 84 is facilitated, and an increase in work time and labor required for construction is suppressed. Therefore, in connection with improving the security against refrigerant leakage, improvement in workability is promoted.

(6-6)
In the air conditioning system 100 according to the above embodiment, the refrigerant communication pipe (La, Ga) includes the branch pipe unit 50, which is assembled in advance and connected to other pipes at the construction site. The branch pipe unit 50 includes an outdoor unit side connection pipe 81 (outdoor pipe), a branch pipe 83 (branch portion), and a shutoff valve 84 that are integrally formed.

  Thereby, the installation of the shut-off valve 84 is particularly easy, and further increases in work time and labor required for construction are further suppressed. Therefore, in connection with improving the security against refrigerant leakage, improvement in workability is promoted.

(7) Modifications The above embodiment can be appropriately modified as shown in the following modifications. Each modification may be applied in combination with another modification as long as no contradiction occurs.

(7-1) Modification 1
In the embodiment described above, the shut-off valves 84 are arranged in each of the liquid side branch portion BPa and the gas side branch portion BPb. In this respect, in order to achieve the effect of more reliably blocking the refrigerant flowing from the outdoor side circuit RC1 to the indoor side circuit RC2 at the time of refrigerant leakage and reducing the amount of refrigerant leaked, the liquid side branch part BPa and the gas side branch part BPb It is preferable that the shut-off valve 84 is arrange | positioned at both. However, the shut-off valve 84 is not necessarily arranged in both the liquid side branch portion BPa and the gas side branch portion BPb, and may be arranged only in one.

  For example, since the indoor expansion valve 41 is controlled to be closed when the refrigerant leaks, the refrigerant flowing from the outdoor circuit RC1 to the indoor circuit RC2 via the liquid communication circuit RC3a can be shut off. The shut-off valve 84 disposed in the portion BPa is not necessarily required and may be omitted as appropriate. In such a case, like the air conditioning system 100 ′ illustrated in FIG. 6, the liquid side branch portion BPa may be configured by a branch pipe unit 50 ′ that does not include the shut-off valve 84.

  Further, for example, when a valve capable of blocking the flow of the refrigerant flowing from the outdoor circuit RC1 to the indoor circuit RC2 of the leakage unit via the gas side communication circuit RC3b at the time of refrigerant leakage is arranged separately, Is controlled to be closed so that the refrigerant flowing from the outdoor circuit RC1 to the indoor circuit RC2 via the gas side communication circuit RC3b can be shut off. The shut-off valve 84 arranged at the branch portion BPb is not necessarily required and may be omitted as appropriate.

(7-2) Modification 2
In the above embodiment, the case where the shutoff valve 84 is an electromagnetic valve that can be switched between open and closed states has been described. However, the shut-off valve 84 is not necessarily limited to an electromagnetic valve, and may be another control valve. For example, the shutoff valve 84 may be an electric valve that can be adjusted in opening. In such a case, the arrangement mode of the shut-off valve 84 in the main unit 51 may be the same as that in the above embodiment, or may be changed as appropriate.

(7-3) Modification 3
In the above embodiment, the case where the branch portion BP is configured by the branch pipe unit 50 has been described. However, the branch portion BP is not necessarily constituted by the branch pipe unit 50, and the branch pipe unit 50 can be omitted as appropriate. That is, in the branch portion BP, pipes and valves (outdoor unit side connection pipe 81, indoor unit side connection pipe 82, branch pipe 83, shutoff valve 84) that are independently carried into the construction site are connected to each other at the construction site. May be configured. Even in such a case, the effects described in (6-1) above can be realized.

(7-4) Modification 4
In the above embodiment, the case where the refrigerant flow path is branched into two in the branch portion BP has been described. However, the number of branches in the branch portion BP is not particularly limited and can be changed as appropriate. For example, in the branch part BP, the refrigerant flow path may be branched into three or more. In such a case, the indoor unit side connection pipes 82 corresponding to the number of branches may be arranged in the branch portion BP, and ports corresponding to the number of the indoor unit side connection pipes 82 may be formed in the branch pipe 83.

(7-5) Modification 5
The configuration aspect of the refrigerant circuit RC in the above embodiment is not necessarily limited to the aspect illustrated in FIG. 1 and can be appropriately changed according to the design specifications and the installation environment. For example, the outdoor first electric valve 16 is not always necessary and can be omitted as appropriate. For example, the subcooler 15 and the outdoor second electric valve 17 are not necessarily required and may be omitted as appropriate. In addition, a device not shown in FIG. 1 may be newly added to the refrigerant circuit RC.

(7-6) Modification 6
In the said embodiment, the controller 70 which controls operation | movement of the air conditioning system 100 was comprised by connecting the outdoor unit control part 30 and the indoor unit control part 48 of each indoor unit 40 via the communication line cb. . However, the configuration of the controller 70 is not necessarily limited to this, and can be appropriately changed according to the design specifications and the installation environment. That is, the configuration aspect of the controller 70 is not particularly limited, and some or all of the elements included in the controller 70 are not necessarily arranged in either the outdoor unit 10 or the indoor unit 40, and other devices It may be arranged in or independently.

  For example, the controller 70 may be configured by another device such as a remote controller 65 or a centralized management device instead of / with one or both of the outdoor unit controller 30 and each indoor unit controller 48. In such a case, other devices may be arranged in a remote place connected to the outdoor unit 10 or the indoor unit 40 via a communication network.

  Further, for example, the controller 70 may be configured only by the outdoor unit control unit 30.

(7-7) Modification 7
In the above embodiment, R32 is used as the refrigerant circulating in the refrigerant circuit RC. However, the refrigerant used in the refrigerant circuit RC is not particularly limited and may be another refrigerant. For example, in the refrigerant circuit RC, and HFC-based refrigerant such as R407C and R410A, CO ₂ or ammonia may be used.

(7-8) Modification 8
In the above embodiment, the idea according to the present disclosure has been applied to the air conditioning system 100. However, the idea according to the present disclosure is not limited to this, and can be applied to other refrigeration apparatuses (for example, a water heater and a heat pump chiller) having a refrigerant circuit.

(7-9) Modification 9
In the above-described embodiment, an example in which the idea according to the present disclosure is applied to an air conditioning system 100 in which two indoor units 40 are connected in parallel to one outdoor unit 10 by connecting pipes (Ga, La). explained. However, the configuration aspect of the air conditioning system to which the idea according to the present disclosure is applied is not necessarily limited to the aspect. That is, regarding the air conditioning system to which the idea according to the present disclosure is applied, the number of outdoor units 10 and / or the indoor units 40 and their connection modes can be appropriately changed according to the installation environment and design specifications.

  For example, in an air conditioning system to which the idea according to the present disclosure is applied, a plurality of outdoor units 10 may be arranged in series or in parallel. In addition, three or more indoor units 40 may be connected to one outdoor unit 10.

  For example, the idea according to the present disclosure is that three or more indoor units 40 are connected to one outdoor unit 10 as in the air conditioning system 200 shown in FIG. And may be applied to an air conditioning system arranged in series or in parallel.

  FIG. 7 is a schematic configuration diagram of the air conditioning system 200. In FIG. 7, the liquid side communication pipe La and the gas side communication pipe Ga are shown together to simplify the illustration.

  In the air conditioning system 200, each communication pipe (La, Ga) extending between the outdoor unit 10 and each indoor unit 40 branches into a plurality (here, four in large), so that the indoor unit 40 arranged at the branch destination. A plurality (four) of groups (AD) are configured. In the air conditioning system 200, each group A-D includes a plurality of indoor units 40, respectively.

  In FIG. 7, the shut-off valve 84 is arranged at the branch portion BP1 located on the start end side (most outdoor unit 10 side) of each group AD. Thereby, when refrigerant leakage occurs in any of the groups A to D, the amount of the leakage refrigerant is suppressed by controlling the shut-off valve 84 to be closed in the branch portion BP1 corresponding to the group in which the refrigerant leakage has occurred. It has come to be. That is, between the outdoor unit 10 and each indoor unit 40, the refrigerant flow path (connection circuit RC3) branches according to the number of indoor units 40 and other devices. In the air conditioning system 200, before the refrigerant flow path branches ( The shut-off valve 84 can be arranged on the branch portion BP on the outdoor unit 10 side), and when shutting off the flow of the refrigerant to the plurality of indoor units 40, the one shut-off valve 84 is connected to the plurality of indoor units. 40 can be shared. As a result, even if the shut-off valve 84 is not provided for each indoor unit 40, the refrigerant flow from the outdoor unit 10 side to the plurality of indoor units 40 can be shut off when the refrigerant leaks. For this reason, it is not necessary to arrange | position the shut-off valve 84 for every indoor unit 40 regarding a refrigerant | coolant leakage countermeasure, and it is suppressed that the number of the shut-off valves 84 increases. Such an effect can be expected particularly when the number of indoor units 40 is large as in the air conditioning system 200. Therefore, in the air conditioning system 200, a decrease in workability is particularly suppressed in connection with improving the safety against refrigerant leakage.

  Further, in the air conditioning system 200, since the number of indoor units 40 is large, if the shutoff valve 84 and the branch pipe are joined on site at the time of construction, the number of man-hours increases remarkably, so that the branch pipe unit 50 including the shutoff valve 84 is obtained. By being constructed on site, the working time and labor required for construction are particularly reduced.

  Further, in the air conditioning system 200, since the shut-off valve 84 is arranged for each group, when refrigerant leakage occurs, only the group in which refrigerant leakage has occurred is shut off, and the group in which refrigerant leakage has not occurred. Can continue driving.

  In the air conditioning system 200, shutoff valves 84 are arranged in the branch portion BP2 closest to the outdoor unit 10, the branch portion BP3 between the branch portion BP2 and the branch portion BP1, and the branch portions BP4-6 in each group. Not. That is, in the air conditioning system 200, the branch portion BP2 and the branch portion BP3 are configured by the branch pipe unit that does not have the shut-off valve 84.

  In the refrigerant circuit RC, the position (branch portion BP) where the shutoff valve 84 is arranged can be changed as appropriate. Specifically, the shut-off valve 84 is based on a refrigerant leakage amount assumed when refrigerant leakage occurs, and a part that needs to be shut off to ensure safety (for example, the branch part BP1- shown in FIG. 7). 6). For example, regarding the position (branch portion BP) where the shut-off valve 84 is disposed, the total number of indoor units 40, the total capacity, or the like that need to be shut off by the shut-off valve 84 to ensure safety when refrigerant leaks. It may be determined based on the total capacity of the end side connecting pipe. Alternatively, the shut-off valve 84 may be arranged for each device including the refrigerant filling amount corresponding to these.

That is, the shutoff valve 84 may be connected to any one of the following (a), (b), and (c) / all outdoor unit side connection pipes 81 (outdoor pipes).
(A): Outdoor unit side connection pipe 81 arranged between a plurality of indoor units 40 having a total capacity equal to or less than the first threshold value ΔTh1 and the outdoor unit 10.
(B): Outdoor unit side connection pipe 81 arranged between the plurality of indoor units 40 whose total number is equal to or smaller than the second threshold value ΔTh2 and the outdoor unit 10.
(C): Outdoor unit side connecting pipe 81 having a total capacity of communicating pipes on the other end side that is not more than the third threshold value ΔTh3

  In this case, the first threshold value ΔTh1, the second threshold value ΔTh2, and / or the third threshold value ΔTh3 is the size of any target space (for example, the narrowest target space) where the indoor unit 40 is installed and air conditioning is performed. Based on the above, it may be set in consideration of the possibility that the concentration of the leaked refrigerant becomes a dangerous value (combustion lower limit concentration or oxygen deficiency limit concentration) in the target space when the refrigerant leak occurs.

For example, the first threshold value ΔTh1, the second threshold value ΔTh2, and / or the third threshold value ΔTh3 are the refrigerant amount m (kg), the refrigerant combustion lower limit concentration G (kg / m ³ ), and the floor space A (m ² ) of the target space. ), The leakage height hr (m) may be set such that the shut-off valve 84 is arranged in a range where the following condition 1 is satisfied. Here, the refrigerant amount m is a refrigerant amount that can be charged into a device that is shut off from the outdoor unit 10 by the shut-off valve 84 in order to ensure the safety in the target space when the refrigerant leaks. The leakage height hr is a height position of a portion where the leakage refrigerant is assumed to flow out in the target space.
m ≤ G / 4 · A · hr (Condition 1)

  By determining the arrangement position of the shutoff valve 84 in such a manner, the safety (for example, the lower limit concentration of combustion and oxygen deficiency) when refrigerant leakage occurs according to the scale and environment of the facility where the air conditioning system is installed. The shut-off valve 84 can be accurately arranged at a portion where it is necessary to shut off the refrigerant in view of the limit concentration and the like. Therefore, ensuring safety against refrigerant leakage is further promoted while suppressing an increase in the number of shut-off valves 84.

(7-10) Modification 10
In the embodiment described above, the main body unit 51 of the branch pipe unit 50 is configured in a manner as shown in FIG. 2, but is not necessarily limited to such a manner and can be appropriately changed. That is, as for each part included in the main unit 51, as long as there is no contradiction in realizing the effect of the idea according to the present disclosure, the configuration, such as the shape, size, position, etc., according to the installation environment and design specifications These changes can be made and may be omitted as appropriate.

  For example, the main unit 51 may be configured as a main unit 51a shown in FIG. Hereinafter, the main unit 51a will be described with respect to portions different from the main unit 51.

  FIG. 8 is a schematic configuration diagram of the main unit 51a. The main unit 51 a has a shut-off valve 84 a instead of the shut-off valve 84. The cutoff valve 84a is different from the cutoff valve 84a in the following points.

  The shut-off valve 84a includes a second pipe connection portion 842a instead of the second pipe connection portion 842. The second pipe connection portion 842a is a tubular portion extending from the side portion of the valve main body portion 840 along a predetermined extending direction (x direction in FIG. 6). In the present embodiment, the shut-off valve 84a is substantially T-shaped and forms a substantially I-shaped refrigerant flow path 840a ′ therein. In this regard, in the shutoff valve 84a, the second pipe connection portion 842a extends in the opposite direction to the first pipe connection portion 841. That is, the extending direction (longitudinal direction) of the second pipe connecting portion 842a and the extending direction (longitudinal direction) of the first pipe connecting portion 841 are the same direction (x direction), but the extending directions of both are opposite. The extending direction of the first pipe connecting portion 841 is a direction that intersects the extending direction of the valve body N1.

  The second pipe connection part 842a communicates with the end of the refrigerant flow path 840a ′ in the valve main body part 840. One end of the second pipe connection portion 842a is joined to the side portion of the valve body portion 840. The other end of the second pipe connection part 842a is joined to the end part of the outdoor unit side connection pipe 81 (the end part on the one end side connection pipe side). More specifically, in the second pipe connection portion 842a, in the installed state, the indoor unit side connection pipes 82 are arranged along the horizontal direction, and the longitudinal direction of the indoor unit side connection pipes 82 extends along the horizontal direction. It is connected to the outdoor unit side connecting pipe 81 in a posture that enables the above.

  Such a main unit 51a may be arranged in a manner as shown in FIG. 9, for example. FIG. 9 is a schematic view showing an example of an installation mode of the branch pipe unit 50 ″ having the main body unit 51a. Hereinafter, in FIG. 9, unlike the installation mode of FIG. 3, the first pipe connection portion 841 of the shut-off valve 84 a is installed so as to extend in the left-right direction (x direction), not in the front-rear direction (z direction). . In this connection, in the ceiling space SP, the main extending direction of the other end side connecting pipe (here, the horizontal direction, that is, the horizontal direction) and the main extending direction of the one end side connecting pipe (here, the left and right direction, that is, the horizontal direction). Are substantially the same. That is, in the ceiling space SP having a small vertical length, the main body unit 51a includes the main extending direction of the other end side connecting pipe (here, the horizontal direction, that is, the horizontal direction) and the main extending direction of the one end side connecting pipe ( Here, they are arranged in such a posture that the left and right direction, that is, the horizontal direction) is substantially the same.

  The branch pipe unit 50 ″ having such a main body unit 51a can also achieve the same operational effects as the above embodiment.

(7-11) Modification 11
For example, the main unit 51 may be configured as a main unit 51b shown in FIG. Hereinafter, the main unit 51b will be described with respect to parts different from the main unit 51.

  FIG. 10 is a schematic configuration diagram of the main unit 51b. The main unit 51 b has a branch pipe 83 a instead of the branch pipe 83. The main unit 51b has three indoor unit side connecting pipes 82.

  The branch pipe 83a is different from the branch pipe 83 in the following points. The branch pipe 83a has a branch pipe main body 830a instead of the branch pipe main body 830. The branch pipe main body 830a is a substantially I-shaped header pipe. The 1st insertion part 831 is extended along the extending | stretching direction (x direction of FIG. 9) of the outdoor unit side connection pipe 81 from the part between the both ends of the branch pipe main-body part 830a. Each second insertion portion 832 is spaced apart from the other second insertion portion 832 in the z direction at a portion opposite to the arrangement position of the outdoor unit side connection pipe 81 between both ends of the branch pipe main body portion 830a. Are arranged in line. Each second insertion portion 832 extends in the opposite direction along the extending direction of the first insertion portion 831, and is disposed substantially parallel to the other second insertion portion 832.

  Even when the branch pipe unit 50 includes such a main body unit 51b, the same effect as that of the above-described embodiment can be realized. Moreover, in the main body unit 51b, since the distance between each 2nd insertion part 832 can be made smaller than the main body unit 51, even if it is a case where the number of the 2nd insertion parts 832 increases, a main body unit. 51b can be configured compactly, and in connection with this, improvement in workability can be expected.

(7-12) Modification 12
In the main unit 51, the outdoor unit side connecting pipe 81 may be omitted as appropriate. In this case, the main unit 51 may be configured as a main unit 51c shown in FIG. 11, for example. Hereinafter, the main unit 51c will be described with respect to parts different from the main unit 51.

  FIG. 11 is a schematic configuration diagram of the main unit 51c. In the main unit 51c, the outdoor unit side connecting pipe 81 is omitted. For this reason, the second pipe connection portion 842 of the shut-off valve 84 is joined (connected) to the first insertion portion 831 of the branch pipe 83.

  Even when the branch pipe unit 50 includes such a main body unit 51c, the same effects as those of the above-described embodiment can be realized.

(7-13) Modification 13
In the main unit 51, any or all of the plurality of indoor unit side connecting pipes 82 may be omitted as appropriate. In this case, the main unit 51 may be configured as a main unit 51d shown in FIG. 12, for example. Hereinafter, the main unit 51d will be described with respect to parts different from the main unit 51.

  FIG. 12 is a schematic configuration diagram of the main unit 51d. In the main unit 51d, each indoor unit side connecting pipe 82 is omitted. For this reason, in the main body unit 51d, the other end side connecting pipes (L2, L3, G2, G3) are joined to the second insertion portion 832 of the branch pipe 83.

  Even when the branch pipe unit 50 includes the main body unit 51d, the same effects as those of the above-described embodiment can be realized.

(7-14) Modification 14
Further, in the main unit 51, the outdoor unit side connecting pipe 81 may be joined to the first pipe connecting portion 841 of the shutoff valve 84. In such a case, the main unit 51 may be configured, for example, as a main unit 51e shown in FIG. Hereinafter, the main unit 51e will be described with respect to parts different from the main unit 51.

  FIG. 13 is a schematic configuration diagram of the main unit 51e. The main unit 51e further includes an outdoor unit side connecting pipe 81, and the outdoor unit side connecting pipe 81 is joined (connected) to one end of the first pipe connecting portion 841 of the shutoff valve 84. . And the one end side connection piping (L1 / G1) is joined to the other end of the outdoor unit side connection pipe 81.

  Even when the branch pipe unit 50 includes the main body unit 51e, the same effects as those of the above-described embodiment can be realized. When the outdoor unit side connecting pipe 81 is joined to the first pipe connecting portion 841 of the shut-off valve 84 as in the main unit 51e, one outdoor unit side is used as in the main unit 51c according to “Modification 3”. The connection pipe 81 may be omitted, and the second pipe connection part 842 of the cutoff valve 84 may be joined (connected) to the first insertion part 831 of the branch pipe 83.

(7-15) Modification 15
In the main unit 51, the valve main body 840 is configured such that the extending direction of the valve body N1 is the z direction, but the extending direction of the valve body N1 is not necessarily limited to the z direction. For example, the main unit 51 may be configured as, for example, a main unit 51f illustrated in FIG. Hereinafter, the main unit 51f will be described with respect to portions different from the main unit 51.

  FIG. 14 is a schematic configuration diagram of the main unit 51f. In the main unit 51f, the valve main body 840 ′ is configured such that the extending direction of the valve body N1 is the x direction. Even when the branch pipe unit 50 includes the main body unit 51f, the same effects as those of the above-described embodiment can be realized.

(7-16) Modification 16
Further, in the main unit 51, the shutoff valve 84 is located between the outdoor unit side connecting pipe 81 and the one end side connecting pipe and is connected to the outdoor unit side connecting pipe 81. However, the arrangement of the shut-off valve 84 is not necessarily limited to this, and the shut-off valve 84 is connected to the indoor unit side connecting pipe 82 as long as no contradiction arises in realizing the effect of the idea according to the present disclosure. May be.

  For example, the main unit 51 may be configured as a main unit 51g shown in FIG. 15, for example. Hereinafter, the main unit 51g will be described with respect to portions different from the main unit 51.

  FIG. 15 is a schematic configuration diagram of the main unit 51g. The main unit 51g has a plurality of shut-off valves 84a similar to the main unit 51a (the same number as the indoor unit side connecting pipes 82) instead of the shut-off valve 84. As will be described later, the shut-off valve 84a arranged in the main unit 51g has a smaller size than that arranged in the main unit 51a.

  In the main body unit 51g, each shut-off valve 84a is associated with one of the indoor unit side connecting pipes 82 on a one-to-one basis. In relation to this, in the main body unit 51g, each shut-off valve 84a is associated one-to-one or one-to-many with one of the other end side connecting pipes (indoor unit 40).

  In the main body unit 51g, one end of the first pipe connecting portion 841 of the shut-off valve 84a is joined to the side portion of the valve main body portion 840, and the other end corresponds to the end portion of the indoor unit side connecting pipe 82 (the other end side connecting pipe). Side end).

  In the main body unit 51g, one end of the second pipe connecting portion 842a of the shut-off valve 84a is joined to the side portion of the valve main body portion 840, and the other end is joined to the corresponding other end side connecting pipe. More specifically, in the second pipe connection portion 842a, in the installed state, the indoor unit side connection pipes 82 are arranged along the horizontal direction, and the longitudinal direction of the indoor unit side connection pipes 82 extends along the horizontal direction. It is connected to the other end side connecting pipe in a posture that enables the

  Such a main unit 51g may be arranged in the same manner as shown in FIG. 9, for example. That is, the main body unit 51g is installed such that the first pipe connection portion 841 of the shut-off valve 84a extends in the left-right direction (x direction) instead of the front-rear direction (z direction). , The main extending direction of the other end side connecting pipe (here, the horizontal direction, ie, the horizontal direction) and the main extending direction of the one end side connecting pipe (here, the left and right direction, ie, the horizontal direction) are substantially the same. May be. That is, in the ceiling space SP having a narrow vertical length, the main unit 51g has a main extending direction of the other end side connecting pipe (here, the horizontal direction, that is, a horizontal direction) and a main extending direction of the one end side connecting pipe ( Here, the left and right directions (ie, the horizontal direction) may be arranged so as to be substantially the same.

  In the shut-off valve 84a disposed in the main unit 51g, the first pipe connecting portion 841 is connected to the indoor unit side connecting pipe 82 having an inner diameter smaller than that of the outdoor unit side connecting pipe 81, and the second pipe connecting portion 842 is one end. It is connected to the other end side connecting pipe whose inner diameter is smaller than that of the side connecting pipe. In this connection, the shut-off valve 84a arranged in the main unit 51g has a smaller size than that arranged in the main unit 51a.

  Even when the branch pipe unit 50 (50 ') has such a main body unit 51g, the same effects as those of the above-described embodiment can be realized.

  That is, the main unit 51g connects the one end side connecting pipe and a plurality of other end side connecting pipes, and communicates with the outdoor unit side connecting pipe 81 communicating with the one end side connecting pipe and the corresponding other end side connecting pipe. A plurality of indoor unit side connection pipes 82, a branch pipe 83 communicating the outdoor unit side connection pipes 81 and the plurality of indoor unit side connection pipes 82, and a corresponding indoor unit side connection pipe 82 to be closed. And a plurality of shut-off valves 84a that prevent the flow of the refrigerant. That is, between the outdoor unit 10 and each indoor unit 40, the refrigerant flow path branches according to the number of indoor units 40 and other devices. Even when the branch pipe unit 50 includes the main body unit 51g, the refrigerant flow path The shut-off valve 84a can be disposed before the branching (more specifically, on the outdoor unit 10 side of the branch pipe 83 located on the indoor unit 40 side of the branch pipe 83). Thereby, in order to interrupt | block the flow of the refrigerant | coolant to the several indoor unit 40, it becomes possible to share the one cutoff valve 84a with respect to the several indoor unit 40. FIG. As a result, even if the shut-off valve 84a is not arranged for each indoor unit 40, the refrigerant flow from the outdoor unit 10 side to the plurality of indoor units 40 can be shut off when the refrigerant leaks. For this reason, it is not necessary to arrange | position the shut-off valve 84a for every indoor unit 40 regarding a refrigerant | coolant leakage countermeasure, and it is suppressed that the number of the shut-off valves 84a installed on refrigerant | coolant communication piping increases.

  The main unit 51g can be installed on the refrigerant communication pipe with the outdoor unit side connecting pipe 81, the plurality of indoor unit side connecting pipes 82, the branch pipe 83, and the plurality of shut-off valves 84a assembled in advance. Is possible. In this respect, if many shut-off valves 84a and branch pipes are joined on site at the time of construction, the number of man-hours increases. However, when the branch pipe unit 50 has the main body unit 51g, the work time and labor required for construction are reduced. It has become so.

  In the main unit 51g, a plurality of shut-off valves 84a are arranged. When the shut-off valve 84a is connected to the indoor unit side connecting pipe 82, the main unit 51g shuts off the outdoor unit side connecting pipe 81. It is possible to use a shut-off valve 84a having a smaller size than when the valve 84a is connected. In relation to this, in the main body unit 51g, despite the arrangement of the plurality of shut-off valves 84a, the downsizing is promoted, and the deterioration of workability is suppressed even in a narrow space.

  Therefore, in connection with improving the safety | security with respect to refrigerant | coolant leakage in an air conditioning system, the fall of workability is suppressed.

  In the main unit 51g, the outdoor unit side connecting pipe 81 is not necessarily required and can be omitted as appropriate. Further, in the main unit 51g, the one shut-off valve 84a (more specifically, the shut-off valve 84a that is one-to-one associated with the other end side connection pipe (indoor unit 40) is not necessarily required. May be omitted as appropriate.

  Of course, the main unit 51g may have a shut-off valve 84 instead of the shut-off valve 84a. In such a case, the main unit 51g may be configured like a main unit 51g ′ shown in FIG. The main unit 51g ′ has a branch pipe 83 ′ instead of the branch pipe 83. The branch pipe 83 ′ is not substantially U-shaped like the branch pipe 83, but is substantially T-shaped. In this regard, in the branch pipe 83 ′, the indoor unit side connection pipe 82 extends along the z direction (horizontal direction). In each shut-off valve 84, the first pipe connection part 841 extending along the z direction is connected to the corresponding indoor unit side connection pipe 82, and the second pipe connection part 842 extending along the x direction is connected to the other end side. Connected to piping. Further, since the main body unit 51g ′ uses the substantially T-shaped branch pipe 83 ′, the x-direction of the main body unit 51g ′ is larger than the case where the substantially U-shaped branch pipe 83 is used like the main body unit 51g. It is possible to reduce the size of the device.

(7-17) Modification 17
Further, the main unit 51 may be configured as a main unit 51h shown in FIG. 17, for example. Hereinafter, the main unit 51h will be described with respect to parts different from the main unit 51g.

  FIG. 17 is a schematic configuration diagram of the main unit 51h. In the main body unit 51h, one end of the first pipe connection portion 841 of the shutoff valve 84a is joined to the side portion of the valve main body portion 840, and the other end is joined to the branch pipe 83. In the main unit 51g, one end of the second pipe connection portion 842a of the shut-off valve 84a is joined to the side portion of the valve main body portion 840, and the other end of the second pipe connection portion 842a is the end of the indoor unit side connection pipe 82. It joins to the part (end part by the side of one end side connection piping).

  Even when the branch pipe unit 50 (50 ′) includes such a main body unit 51h, the same operational effects as when the branch pipe unit 50 includes the main body unit 51g can be realized.

(7-18) Modification 18
Further, when the branch pipe unit 50 (50 ′) has the main unit 51g (51g ′) or the main unit 51h, for example, an air conditioning system 300 shown in FIG. It may be applied to an air conditioning system that is connected to the unit 10 and in which each indoor unit 40 is arranged in series or in parallel with the other indoor units 40. FIG. 18 is a schematic configuration diagram of an air conditioning system 300 to which the main body unit 51g (51g ′) or the branch pipe unit 50 having the main body unit 51h is applied. In FIG. 18, the liquid side communication pipe La and the gas side communication pipe Ga are shown together to simplify the illustration.

  In the air conditioning system 300, like the air conditioning system 200, each connecting pipe (La, Ga) extending between the outdoor unit 10 and each indoor unit 40 branches into a plurality (here, four in large), and is arranged at the branch destination. A plurality (four) of groups (AD) are configured with respect to the indoor unit 40 to be performed. In the air conditioning system 300, each group A-D includes a plurality of indoor units 40.

  In FIG. 18, the branch portion BP1 located on the start end side (most outdoor unit 10 side) of each group AD is configured by a branch pipe unit 50 having a main body unit 51g or a main body unit 51h. In FIG. 18, one shut-off valve 84a is associated with the indoor unit 40 located closest to the outdoor unit 10 in the group on a one-to-one basis, and is controlled to the closed state to the corresponding indoor unit 40. Block the flow of refrigerant. The other shut-off valve 84a is associated with the other indoor units 40 included in the group in a one-to-many manner, and is prevented from flowing into the corresponding indoor unit 40 by being controlled to be closed. . That is, in the air conditioning system 300 as well, one shutoff valve 84 a is shared by the plurality of indoor units 40 in order to block the flow of the refrigerant to the plurality of indoor units 40.

  When the branch pipe unit 50 is configured and arranged in the manner as shown in FIG. 18, when refrigerant leakage occurs in any of the groups AD, each of the branch portions BP1 corresponding to the group in which the refrigerant leakage occurs By controlling the shut-off valve 84a to the closed state, the amount of refrigerant leaked is suppressed. As a result, even if the shut-off valve 84a is not arranged for each indoor unit 40, the refrigerant flow from the outdoor unit 10 side to the plurality of indoor units 40 can be shut off when the refrigerant leaks. For this reason, it is not necessary to arrange | position the shut-off valve 84a for every indoor unit 40 regarding a refrigerant | coolant leakage countermeasure, and it is suppressed that the number of the shut-off valves 84a increases. Such an effect can be expected particularly when the number of indoor units 40 is large as in the air conditioning system 300. Therefore, in the air conditioning system 300, a decrease in workability is particularly suppressed in connection with improving the safety against refrigerant leakage.

  Further, in the air conditioning system 300, since the number of indoor units 40 is large, if the control valve and the branch pipe are joined in the field at the time of construction, the man-hour is remarkably increased. Labor is particularly reduced.

  Further, in the air conditioning system 300, since the branch pipe unit 50 is arranged for each group, when refrigerant leakage occurs, only the group in which refrigerant leakage has occurred is blocked and the group in which refrigerant leakage does not occur Can continue driving.

  In the air conditioning system 300, the shutoff valve 84a is not arranged in the branch portion BP2 closest to the outdoor unit 10, the branch portion BP3 between the branch portion BP2 and the branch portion BP1, and the branch portions BP4-6 in each group. . That is, in the air conditioning system 300, the branch portion BP2 and the branch portion BP3 are configured by the branch pipe unit 50 that does not have the shut-off valve 84a.

  In the refrigerant circuit RC, the position (branch portion BP) where the shut-off valve 84a is disposed can be changed as appropriate. Specifically, the shut-off valve 84a is a portion that needs to be shut off for ensuring safety based on the amount of refrigerant leakage that is assumed when refrigerant leakage occurs (for example, the branch portion BP1- shown in FIG. 18). 6). For example, regarding the position (branch portion BP) where the shut-off valve 84a is disposed, the total number of indoor units 40, the total capacity, or the like that need to be shut off by the shut-off valve 84a to ensure safety when refrigerant leaks. It may be determined based on the total capacity of the end side connecting pipe. Or the cutoff valve 84a may be arrange | positioned for every apparatus in which the refrigerant | coolant filling amount equivalent to these is contained.

In other words, the shutoff valve 84a may be connected to any one or all of the following (d), (e), and (f) indoor unit side connection pipes 82 (indoor side pipes).
(D): Indoor unit side connecting pipe 82 arranged between the plurality of indoor units 40 whose total capacity is equal to or less than the fourth threshold value ΔTh4 and the outdoor unit 10.
(E): Indoor unit side connecting pipe 82 arranged between the plurality of indoor units 40 whose total number is equal to or smaller than the fifth threshold value ΔTh5 and the outdoor unit 10.
(F): The indoor unit side connecting pipe 82 in which the total capacity of the communicating pipes on the other end side is 6th threshold value ΔTh6 or less.

  In this case, the fourth threshold value ΔTh4, the fifth threshold value ΔTh5, and / or the sixth threshold value ΔTh6 is the size of any target space (for example, the narrowest target space) where the indoor unit 40 is installed and air conditioning is performed. Based on the above, it may be set in consideration of the possibility that the concentration of the leaked refrigerant becomes a dangerous value (combustion lower limit concentration or oxygen deficiency limit concentration) in the target space when the refrigerant leak occurs.

  For example, the fourth threshold value ΔTh4, the fifth threshold value ΔTh5, and / or the sixth threshold value ΔTh6 is set so that the shutoff valve 84a is arranged in a range in which the above-described condition 1 (see Modification 9) is satisfied. May be.

  By determining the arrangement position of the shut-off valve 84a in such a manner, the safety (for example, the lower limit concentration of combustion and oxygen deficiency) when refrigerant leakage occurs according to the scale and environment of the facility where the air conditioning system is installed. The shut-off valve 84a can be accurately arranged at a portion where it is necessary to shut off the refrigerant in view of the limit concentration and the like. Therefore, ensuring safety against refrigerant leakage is further promoted while suppressing an increase in the number of shutoff valves 84a.

  In FIG. 18, one shutoff valve 84a is associated with the indoor unit 40 located closest to the outdoor unit 10 in the group on a one-to-one basis, but the other shutoff valve 84a is also associated with the other shutoff valve 84a. Similarly to 84a, the indoor units 40 may be associated one-to-many. Further, the shut-off valve 84a is not necessarily required and may be omitted as appropriate.

(7-19) Modification 19
Although not specifically described in the above embodiment, the main body unit 51 and a part of the one end side connecting pipe and / or the other end side connecting pipe may be brought into the field in an integrated state and installed. Good. That is, the main unit 51 and a part of the one end side connecting pipe and / or the other end side connecting pipe may be connected (joined) in advance at a factory or the like.

  In particular, in FIG. 3, the one end side connecting pipe is curved in the vicinity of the connection portion with the main unit 51. As described above, when the refrigerant communication pipe includes a curved portion, the labor required for the construction is particularly reduced by performing the construction in a state in which the curved portion is configured integrally with the main body unit 51 in advance. That is, the workability is improved.

  In such a case, with respect to a part of the refrigerant communication pipe integrated with the main unit 51, if the viewpoint is changed, the constituent elements of the main unit 51 (for example, the outdoor unit side connection pipe 81 and / or the indoor unit side connection pipe 82). ).

(7-20) Modification 20
Although not specifically described in the above embodiment, the main body unit 51 and the heat insulating material 95 may be carried into the site and installed in an integrated state. That is, the main body unit 51 may be covered with the heat insulating material 95 in advance at a factory or the like. Thereby, the labor required for construction is reduced and the workability is improved. In such a case, the heat insulating material 95 integrated with the main body unit 51 can be interpreted as a component of the main body unit 51 from a different viewpoint.

  In addition, about the part connected with other piping in a construction site, after connecting with other piping, what is necessary is just to coat | cover with the heat insulating material 95 anew.

(7-21) Modification 21
In the above embodiment, in the electrical component unit 52, the electrical component 521 is mounted on the substrate 522. However, the electrical component 521 is not necessarily mounted on the substrate 522. For example, the electrical component 521 may be independently arranged in the unit casing 523.

(7-22) Modification 22
In the said embodiment, the electric wire 53 was comprised by the dimension of the longitudinal direction to 1.2 m. However, the electric wire 53 does not necessarily need to be configured in such a manner, and the longitudinal dimension of the electric wire 53 can be changed as appropriate. For example, the electric wire 53 may have a longitudinal dimension of 1 m or 2 m.

  In addition, in the construction site, it is possible to install the main unit 51 and the electrical component unit 52 apart from each other by 1 m or more, and according to the viewpoint of improving the degree of freedom of construction, the longitudinal dimension is 1.0 m or more. Thus, the electric wire 53 is preferably configured. However, the configuration aspect of the electric wire 53 is not necessarily limited to this, and the dimension in the longitudinal direction may be less than 1 m.

(7-23) Modification 23
In the above embodiment, the electrical component unit 52 is provided independently of the main body unit 51 so as to be freely moved with respect to the main body unit 51. In this regard, according to the viewpoint that the electrical component unit 52 is configured independently of the main body unit 51, the electrical component unit 52 can be moved at the site to increase the degree of freedom of construction and to make each unit compact. The electrical component unit 52 is preferably configured in such a manner. However, the present invention is not necessarily limited thereto, and the electrical component unit 52 may be configured integrally with the main body unit 51.

(7-24) Modification 24
In the above embodiment, the case where the outdoor unit side connecting pipe 81 and the branch pipe 83 are joined and the indoor unit side connecting pipe 82 and the branch pipe 83 are joined has been described with respect to the main body unit 51. In this regard, any / all of the outdoor unit side connecting pipe 81 and each indoor unit side connecting pipe 82 may be integrally formed with the branch pipe 83.

(7-25) Modification 25
In the above embodiment, the case where the outdoor unit side connecting pipe 81, the indoor unit side connecting pipe 82, and the branch pipe 83 are made of the same copper as the one end side connecting pipe has been described with respect to the main body unit 51. However, the material of the outdoor unit side connecting pipe 81, the indoor unit side connecting pipe 82, the branch pipe 83, and the other parts of the main unit 51 is not particularly limited, and can be appropriately selected according to the design specifications and installation environment. That's fine.

(7-26) Modification 26
In the above embodiment, the case where the main unit 51 has one outdoor unit side connection pipe 81 and two indoor unit side connection pipes 82 has been described. However, the number of outdoor unit side connection pipes 81 and the number of indoor unit side connection pipes 82 in the main unit 51 are not necessarily limited to this, and can be changed as appropriate. For example, the main unit 51 may have two or more outdoor unit side connecting pipes 81. The main unit 51 may have three or more indoor unit side connecting pipes 82. That is, the number of branches in the main unit 51 (branch portion BP) is not limited to two and may be three or more.

(7-27) Modification 27
In the above embodiment, the case where the main unit 51 is installed without being housed in a casing or the like has been described. In this respect, from the viewpoint of promoting compactness, the main unit 51 is preferably installed in such a manner. However, the installation mode of the main unit 51 is not necessarily limited to this, and may be appropriately selected according to design specifications and installation environment. For example, the main unit 51 may be installed in a state accommodated in a casing.

(7-28) Modification 28
In the above embodiment, the case where the electrical component unit 52 is suspended from the ceiling space SP by mounting the fixture 90 fixed to the ceiling surface C2 has been described. However, the installation mode of the electrical component unit 52 is not necessarily limited to this, and can be appropriately changed according to design specifications and installation environment. For example, the electrical component unit 52 may be installed by being placed on the ceiling bottom surface C1 or a beam, or may be installed by being fixed to a pillar or a wall.

(7-29) Modification 29
In the above embodiment, in the branch pipe unit 50, the outdoor unit side connection pipe 81 (outdoor pipe), the plurality of indoor unit side connection pipes 82 (indoor side pipe group), the branch pipe 83 (branch part), and the cutoff The valve 84 is integrally formed. However, the branch pipe unit 50 does not necessarily need to be configured in such a manner, and any element may be configured as a separate body and may be configured to be connected to other elements at the site.

  For example, the plurality of indoor unit side connecting pipes 82 (indoor side piping group) may be configured not to be included in the branch pipe unit 50 but to be independently carried into the construction site and connected to other pipes.

  Further, for example, the shut-off valve 84 is not necessarily configured integrally with other elements included in the branch pipe unit 50. That is, the shut-off valve 84 may be configured to be independently carried into the construction site and connected to other piping. Even in such a case, the effects described in (6-1) above can be realized.

(7-30) Modification 30
Any of the valves arranged in the refrigerant circuit RC according to the above embodiment has a liquid seal suppression structure that suppresses the formation of a liquid seal circuit in the refrigerant circuit RC when the shutoff valve 84 is closed. You may do it. For example, any / all of the indoor expansion valve 41, the shut-off valve 84, and the outdoor first electric valve 16 may have a liquid seal suppression structure. The liquid seal suppression structure is not particularly limited as long as it is a structure that suppresses the formation of the liquid seal circuit. For example, as the liquid seal suppression structure, a minute flow path that allows a small amount of refrigerant to pass in the closed state may be formed in the valve. In such a case, a minute flow path may be formed by forming a notch or the like in the valve seat or the valve body. In addition, for example, as a liquid seal suppression structure, a valve may be configured to allow a small amount of refrigerant to pass when a pressure higher than a predetermined value is applied even in a closed state.

  Further, instead of arranging / disposing a valve having a liquid seal suppression structure, a liquid seal suppression mechanism may be arranged in the refrigerant circuit RC. The liquid seal suppression mechanism is a mechanism that suppresses the formation of a liquid seal circuit in the refrigerant circuit when the control valve is closed. The liquid seal suppression mechanism is not particularly limited as long as it is a mechanism that suppresses the formation of the liquid seal circuit. For example, in the refrigerant circuit RC, a refrigerant pipe that forms a bypass circuit that bypasses the refrigerant from the flow path on one end side to the flow path on the other end side of the shutoff valve 84 may be arranged as a liquid seal suppression mechanism. In such a case, the liquid seal suppression mechanism may include a check valve that is arranged on the bypass circuit and allows the refrigerant to flow only in one direction, or an on-off valve that switches between opening and closing of the bypass circuit.

  This suppresses the formation of a liquid ring circuit in the refrigerant circuit RC when the refrigerant leaks and the shut-off valve 84 is closed. That is, in the above embodiment, the indoor expansion valve 41 is controlled to be closed in the first refrigerant leakage control, and the shutoff valve 84 is controlled to be closed in the third refrigerant leakage control. For this reason, a liquid ring circuit can be formed in the refrigerant circuit RC. For example, a liquid ring circuit can be formed between the shutoff valve 84 and the indoor expansion valve 41 of the branch pipe unit 50 (50a or 50b). Further, for example, a liquid ring circuit can be formed between the shutoff valve 84 of the branch pipe unit 50 (50a) and the outdoor first electric valve 16.

  However, for example, any / all of the indoor expansion valve 41, the shut-off valve 84, and the outdoor first electric valve 16 have a liquid seal suppression structure, so that the formation of such a liquid seal circuit is suppressed. . Further, for example, in the refrigerant circuit RC, a bypass circuit that bypasses the refrigerant from the flow path between the shut-off valve 84 and the indoor expansion valve 41 to the flow path closer to the outdoor unit 10 than the shut-off valve 84 is formed as a liquid seal suppression mechanism. By arranging the refrigerant piping to be performed, the formation of the liquid ring circuit is suppressed. Therefore, the occurrence of damage to the device due to the formation of the liquid ring circuit when the refrigerant leaks is suppressed. That is, a decrease in reliability is suppressed.

(8)
Although the embodiments have been described above, it will be understood that various changes in form and details can be made without departing from the spirit and scope described in the claims.

  The present disclosure can be used for an air conditioning system.

10: Outdoor units 40, 40a, 40b: Indoor unit 41: Indoor expansion valve (electric valve)
50, 50 ', 50'': Branch pipe unit 50a: First branch pipe unit 50b: Second branch pipe unit 51, 51a-h: Main unit 52: Electrical component unit 53: Electric wire unit 60: Refrigerant leakage sensor 65: Remote control 70: Controller 81: Outdoor unit side connection pipe (outdoor pipe)
82: Indoor unit side connection pipe (indoor side piping)
83, 83 ', 83a: Branch pipe (branch part)
84, 84a: shut-off valve (control valve)
90: fixture 95: heat insulating material 100, 100 ', 200, 300: air conditioning system 521: electrical component 522: substrate 523: unit casing 524: fixed portion 830: branch pipe main body 830a: branch pipe main body 831: first Insertion part 832: 2nd insertion part 840, 840 ': Valve main-body part 841: 1st piping connection part 842, 842a: 2nd piping connection part AD: Group BP, BP1-6: Branch part (1st portion)
BPa: Liquid side branch part (first part)
BPb: Gas side branch portion (first portion)
C1: Ceiling back bottom C2: Ceiling back top G1: First gas side connecting pipe G2: Second gas side connecting pipe G3: Third gas side connecting pipe Ga: Gas side connecting pipe (refrigerant connecting pipe)
L1: First liquid side connecting pipe L2: Second liquid side connecting pipe L3: Third liquid side connecting pipe La: Liquid side connecting pipe (refrigerant connecting pipe)
P1-P11: 1st piping P1- 11th piping P17-P18: 17th piping P17-18th piping RC: Refrigerant circuit RC1: Outdoor side circuit RC2: Indoor side circuit RC3: Communication circuit RC3a: Liquid side communication circuit RC3b: Gas side connection circuit SP: Ceiling space

Japanese Patent Laid-Open No. 5-118720

  The present disclosure relates to an air conditioning system.

  In the air conditioning system, there is a possibility that the refrigerant leaks from the refrigerant circuit due to damage to the equipment constituting the refrigerant circuit or poor installation. Therefore, it is necessary to take measures to ensure the safety when the refrigerant leaks. Become. In particular, recently, from the viewpoint of improving energy saving and reducing environmental load, for example, a slightly flammable refrigerant such as R32 (combustibility is not large, but the characteristic of burning when the concentration becomes a predetermined value (combustion lower limit concentration) or more is shown. And the demand for such measures is increasing.

  Conventionally, as measures against refrigerant leakage, for example, as disclosed in Japanese Patent Application Laid-Open No. 5-118720, a predetermined control valve (electromagnetic valve or motor-operated valve) is provided in the refrigerant circuit when refrigerant leakage is detected. By controlling the opening control valve to the closed state (minimum opening), the refrigerant flow to the indoor unit is obstructed, and the space where the indoor unit is installed (the living space or warehouse where people enter and exit) There has been proposed a method for suppressing further refrigerant leakage into an internal space or the like. In Patent Document 1, in an air conditioning system including a plurality of indoor units in the same refrigerant system, when a pair of control valves are arranged for each indoor unit on a communication pipe between the outdoor unit and the indoor unit, and refrigerant leakage occurs. The corresponding control valve is controlled to be closed.

  Here, in an air conditioning system applied in a large-scale facility such as a building or a factory, the number of indoor units to be constructed increases according to the size of the facility. Therefore, when a pair of control valves is arranged for each indoor unit as in Patent Document 1, the cost increases remarkably according to the number of indoor units.

  Further, the connecting pipe between the outdoor unit and the indoor unit is usually constructed in a narrow ceiling space. In this regard, when a control valve is arranged for each indoor unit as in Patent Document 1, it is necessary to install a large number of control valves on the connection pipe as the number of indoor units increases, and the work time required for construction and The labor will be remarkably increased and the workability will not be excellent.

  In relation to improving the security against refrigerant leakage, an air conditioning system that is excellent in cost control and workability is provided.

  An air conditioning system according to a first aspect is an air conditioning system that performs a refrigeration cycle in a refrigerant circuit, and includes an outdoor unit, a plurality of indoor units, a refrigerant communication pipe, and a control valve. The refrigerant communication pipe connects the outdoor unit and the indoor unit. The control valve is disposed on the refrigerant communication pipe. The control valve impedes the refrigerant flow. The refrigerant communication pipe includes a plurality of indoor side pipes, outdoor side pipes, and branch portions. The indoor side piping communicates with the corresponding indoor unit. The outdoor piping communicates with a plurality of corresponding indoor piping on the outdoor unit side. The branch portion connects the indoor-side piping group and the outdoor-side piping. An indoor side piping group is a piping group comprised by two or more indoor side piping. The outdoor pipe forms a common refrigerant flow path for both the refrigerant flowing from the outdoor unit side to the indoor unit side via the corresponding indoor pipe and the refrigerant flowing from the indoor unit to the outdoor unit via the corresponding indoor pipe. To do. The control valve is disposed on the outdoor pipe.

  In the air conditioning system according to the first aspect, the number of control valves increases according to the number of indoor units by disposing the control valves on the outdoor side piping to block the refrigerant flow to the plurality of indoor units. Is suppressed. That is, the flow of the refrigerant that flows from the outdoor pipe (outdoor unit side) to the corresponding indoor pipe group (a plurality of indoor units) when the refrigerant leaks by arranging the control valve closer to the outdoor unit than the indoor pipe group. Can be prevented. For this reason, it is not necessary to arrange a control valve for each indoor unit in order to ensure the safety related to refrigerant leakage, and the increase in the number of control valves according to the number of indoor units is suppressed.

  In addition, the refrigerant communication pipe between the outdoor unit and the indoor unit is usually constructed in a narrow ceiling space, and it is possible to suppress an increase in the number of control valves installed on the refrigerant communication pipe. Therefore, the increase in work time and labor required for construction is also suppressed.

  Therefore, in connection with improving the security against refrigerant leakage, cost reduction and workability improvement are promoted.

  An air conditioning system according to a second aspect is an air conditioning system that performs a refrigeration cycle in a refrigerant circuit, and includes an outdoor unit, a plurality of indoor units, a refrigerant communication pipe, and a control valve. The refrigerant communication pipe connects the outdoor unit and the indoor unit. The control valve is disposed on the refrigerant communication pipe. The control valve impedes the refrigerant flow. The refrigerant communication pipe includes a plurality of indoor side pipes, outdoor side pipes, and branch portions. The indoor side piping communicates with the corresponding indoor unit. The outdoor piping communicates with a plurality of corresponding indoor piping on the outdoor unit side. The branch portion connects the indoor-side piping group and the outdoor-side piping. An indoor side piping group is a piping group comprised by two or more indoor side piping. The outdoor pipe forms a common refrigerant flow path for both the refrigerant flowing from the outdoor unit side to the indoor unit side via the corresponding indoor pipe and the refrigerant flowing from the indoor unit to the outdoor unit via the corresponding indoor pipe. To do. A control valve is arrange | positioned on corresponding indoor side piping.

  In the air conditioning system according to the second aspect, an increase in the number of control valves according to the number of indoor units is suppressed. That is, the control valve for blocking the flow of the refrigerant to the plurality of indoor units is arranged on the indoor side pipe arranged on the outdoor unit side of these indoor units, so that the outdoor pipe (outdoor It becomes possible to prevent the flow of the refrigerant flowing from the unit side) to these indoor units. For this reason, it is not necessary to arrange a control valve for each indoor unit in order to ensure the safety related to refrigerant leakage, and the increase in the number of control valves according to the number of indoor units is suppressed.

  In addition, the refrigerant communication pipe between the outdoor unit and the indoor unit is usually constructed in a narrow ceiling space, and it is possible to suppress an increase in the number of control valves installed on the refrigerant communication pipe. Therefore, the increase in work time and labor required for construction is also suppressed. Moreover, it becomes possible to use a control valve with a small dimension by arrange | positioning a control valve on indoor side piping compared with the case where a control valve is arrange | positioned on outdoor side piping. In connection with this, downsizing is promoted, and a decrease in workability is suppressed even in a narrow space.

  Therefore, in connection with improving the security against refrigerant leakage, cost reduction and workability improvement are promoted.

  The air conditioning system which concerns on a 3rd viewpoint is an air conditioning system which concerns on a 1st viewpoint or a 2nd viewpoint, Comprising: Refrigerant communication piping contains multiple 1st parts. The first part is a part having one outdoor pipe, one branch part, and an indoor pipe group. When the control valve is arranged on the outdoor pipe, the control valve is arranged on the outdoor pipe in a part of the first part. When the control valve is arranged on the indoor side pipe, the control valve is arranged on the indoor side pipe in a part of the first part.

  Here, in the case where the refrigerant communication pipe includes a plurality of first parts, the control valve is arranged only in a specific first part (for example, the first part closest to the outdoor unit), so that the other first part Even if the control valve is omitted, it is possible to prevent the flow of refrigerant flowing from the outdoor unit side to each indoor unit side. For this reason, in the case where a plurality of first parts are included in the refrigerant communication pipe, the number of control valves can be increased while ensuring the safety of refrigerant leakage by arranging the control valves only in a part of the first parts. It can be suppressed from increasing. The air conditioning system which concerns on a 2nd viewpoint is based on the thought which concerns. Therefore, in connection with improving the security against refrigerant leakage, cost reduction and workability improvement are further promoted.

  The air conditioning system which concerns on a 4th viewpoint is a refrigerant | coolant air conditioning system which concerns on either of the 1st viewpoint to the 3rd viewpoint, Comprising: A refrigerant | coolant communication piping contains a gas side communication piping and a liquid side communication piping. The gas side communication pipe is a pipe through which a low-pressure refrigerant flows. The liquid side communication pipe is a pipe through which a high-pressure or intermediate-pressure refrigerant flows. When the control valve is disposed on the outdoor pipe, the control valve is disposed on the outdoor pipe included in the gas side communication pipe. When the control valve is arranged on the indoor side pipe, the control valve is arranged on the indoor side pipe included in the gas side communication pipe.

  Here, in the outdoor unit or the indoor unit, an electronic expansion valve for reducing the pressure of the refrigerant is usually disposed on the refrigerant flow path communicating with the liquid side communication pipe. When the refrigerant leaks, it is possible to prevent the flow of the refrigerant flowing from the outdoor unit to the indoor unit through the liquid side connection pipe by controlling the electronic expansion valve to the minimum opening. On the other hand, since there are many cases in which a control valve similar to the electronic expansion valve is not arranged on the refrigerant flow path communicating with the gas side communication pipe, in order to ensure the security against refrigerant leakage, the indoor unit is connected via the gas side communication pipe. It is important to prevent the flow of refrigerant toward the side.

In the air conditioning system according to the fourth aspect , the control valve is arranged on the outdoor side pipe or the indoor side pipe included in the gas side communication pipe. Ensuring security is promoted.

  The air conditioning system which concerns on a 5th viewpoint is an air conditioning system which concerns on a 4th viewpoint, Comprising: When a control valve is arrange | positioned on outdoor side piping, it arrange | positions also on outdoor side piping contained in liquid side connection piping Is done. When the control valve is arranged on the indoor side pipe, the control valve is also arranged on the indoor side pipe included in the liquid side connecting pipe.

In the air conditioning system according to the fifth aspect , the control valve is also arranged on the outdoor side pipe or the indoor side pipe included in the liquid side communication pipe, thereby further promoting the securing of safety against refrigerant leakage.

  The air conditioning system which concerns on a 6th viewpoint is an air conditioning system which concerns on either of the 1st viewpoint to the 5th viewpoint, Comprising: An indoor unit contains a motor operated valve. The motor-operated valve decompresses the refrigerant according to the opening degree during operation. When the refrigerant leaks, the motor-operated valve is closed to prevent the refrigerant flowing into the indoor unit.

In the air conditioning system according to the sixth aspect , an electric valve that prevents the flow of the refrigerant by being controlled to be closed when refrigerant leakage occurs is arranged in the indoor unit, so that when the refrigerant leaks from the outdoor unit to the indoor unit It becomes possible to cut off the flow of the refrigerant more reliably. Therefore, ensuring safety against refrigerant leakage is further promoted.

The air conditioning system according to the seventh aspect is the air conditioning system according to any of the first to sixth aspects, and when the control valve is disposed on the outdoor pipe, the following A, B and C: It is arrange | positioned on any / all outdoor piping. When the control valve is arranged on the indoor side pipe, it is arranged on any / all of the following D, E and F indoor pipes.
A: Outdoor piping arranged between a plurality of indoor units whose total capacity is equal to or less than a first threshold and an outdoor unit B: A plurality of indoor units whose total number is equal to or less than a second threshold, and an outdoor unit Outdoor pipe C arranged between the outdoor unit pipe D: the outdoor pipe D having a total capacity of refrigerant communication pipes located on the indoor unit side being a third threshold value or less, and a plurality of indoor units having a total capacity being a fourth threshold value or less. The indoor side pipe E arranged between the outdoor unit and the outdoor unit. The indoor side pipe F arranged between the plurality of indoor units whose total number is equal to or smaller than the fifth threshold and the outdoor unit F: on the indoor unit side. Indoor piping where the total capacity of the refrigerant communication piping positioned is not more than the sixth threshold value

  This makes it necessary to shut off the refrigerant in view of safety (for example, lower combustion limit concentration) when refrigerant leakage occurs, depending on the scale and environment of the facility where the air conditioning system is installed (outdoors) In the piping), the control valve can be accurately arranged. Therefore, ensuring the security against refrigerant leakage is further promoted while the increase in the number of control valves is suppressed.

  An air conditioning system according to an eighth aspect is the air conditioning system according to the seventh aspect, wherein the first threshold, the second threshold, the third threshold, the fourth threshold, the fifth threshold, and the sixth threshold are an indoor unit Is set based on the size of one of the target spaces where air conditioning is performed.

  As a result, depending on the scale and environment of the facility where the air conditioning system is installed, the control valve is installed in the part (outdoor piping) where it is necessary to shut off the refrigerant in view of the safety when refrigerant leakage occurs. Accurate placement is further facilitated. That is, the first threshold value, the second threshold value, the third threshold value, the fourth threshold value, the fifth threshold value, and / or the sixth threshold value, which are used as a reference when determining the arrangement position of the control valve, are targets for installing the indoor unit It can be set based on a risk value (combustion lower limit concentration, oxygen deficiency concentration, etc.) determined according to the size of the space (for example, the narrowest target space). Therefore, ensuring the security against refrigerant leakage is further promoted while the increase in the number of control valves is suppressed.

  The air conditioning system which concerns on a 9th viewpoint is an air conditioning system which concerns on either of the 1st viewpoint to the 8th viewpoint, Comprising: An outdoor side piping and / or indoor side piping are comprised integrally with a branch part and a control valve. Thereby, installation of a control valve becomes easy and it is further suppressed that the working time and labor which construction requires increase. Therefore, in connection with improving the security against refrigerant leakage, the workability improvement is further promoted.

  An air conditioning system according to a tenth aspect is the air conditioning system according to the ninth aspect, wherein the refrigerant communication pipe includes a branch pipe unit. The branch pipe unit is assembled in advance and connected to other pipes at the construction site. The branch pipe unit includes an outdoor pipe and / or an indoor pipe, a branch portion, and a control valve that are integrally formed.

  This makes it particularly easy to install the control valve and further suppresses an increase in work time and labor required for construction. Therefore, in connection with improving the security against refrigerant leakage, the workability improvement is further promoted.

  An air conditioning system according to an eleventh aspect is the air conditioning system according to any one of the first to tenth aspects, and any of the valves arranged in the refrigerant circuit has a liquid seal suppression structure. Instead of / with this, a liquid seal suppression mechanism is arranged in the refrigerant circuit. The liquid seal suppression structure is a structure that suppresses formation of a liquid seal circuit in the refrigerant circuit when the control valve is closed. The liquid seal suppression mechanism is a mechanism that suppresses the formation of a liquid seal circuit in the refrigerant circuit when the control valve is closed. Thereby, when a refrigerant leak arises and a control valve will be in a closed state, it is suppressed that a liquid seal circuit is formed in a refrigerant circuit.

  The liquid seal suppression structure is not particularly limited as long as it is a structure that suppresses the formation of the liquid seal circuit. For example, as the liquid seal suppression structure, a minute flow path that allows a small amount of refrigerant to pass in the closed state may be formed in the valve. In addition, for example, as a liquid seal suppression structure, a valve may be configured to allow a small amount of refrigerant to pass when a pressure higher than a predetermined value is applied even in a closed state.

  The liquid seal suppression mechanism is not particularly limited as long as it is a mechanism that suppresses the formation of the liquid seal circuit. For example, in the refrigerant circuit, a pipe that forms a bypass circuit that bypasses the refrigerant from the flow path on one end side of the control valve to the flow path on the other end side may be arranged as a liquid seal suppression mechanism. In such a case, the liquid seal suppression mechanism may include a check valve that is arranged on the bypass circuit and allows the refrigerant to flow only in one direction, or an on-off valve that switches between opening and closing of the bypass circuit.

1 is a schematic configuration diagram of an air conditioning system according to an embodiment of the present disclosure. The schematic block diagram of a main-body unit. The schematic diagram which showed an example of the installation aspect of a branch pipe unit. The block diagram which showed roughly the controller and each part connected to a controller. The flowchart which showed an example of the flow of a process of a controller. The schematic block diagram of the air conditioning system which concerns on the modification 1. FIG. The schematic block diagram of the air conditioning system which concerns on the modification 9. FIG. FIG. 11 is a schematic configuration diagram of a main unit according to Modification Example 10. The schematic diagram which showed an example of the installation aspect of the branch pipe unit which has a main body unit which concerns on the modification 10. As shown in FIG. The schematic block diagram of the main body unit which concerns on the modification 11. As shown in FIG. The schematic block diagram of the main body unit which concerns on the modification 12. FIG. The schematic block diagram of the main body unit which concerns on the modification 13. As shown in FIG. The schematic block diagram of the main body unit which concerns on the modification 14. The schematic block diagram of the main body unit which concerns on the modification 15. FIG. FIG. 16 is a schematic configuration diagram of a main unit according to Modification Example 16. FIG. 16 is a schematic configuration diagram of another main body unit according to Modification Example 16. The schematic block diagram of the main body unit which concerns on the modification 17. FIG. The schematic block diagram of the air conditioning system which concerns on the modification 18. FIG.

  Hereinafter, an air conditioning system 100 according to an embodiment of the present disclosure will be described with reference to the drawings. The following embodiment is a specific example, does not limit the technical scope, and can be appropriately changed without departing from the gist. In the present specification, “liquid refrigerant” includes not only a liquid refrigerant in a saturated liquid state but also a gas-liquid two-phase refrigerant in a gas-liquid two-phase state. The “closed state” is a minimum opening (including a fully closed state) that the valve can take, and the “open state” is an opening larger than the minimum opening.

(1) Air conditioning system 100
FIG. 1 is a schematic configuration diagram of an air conditioning system 100. The air conditioning system 100 is a refrigeration apparatus that performs air conditioning such as cooling or heating of a target space (a living space, a storage space, a low-temperature warehouse, a transport container, or the like) by a vapor compression refrigeration cycle. The air conditioning system 100 mainly includes an outdoor unit 10, a plurality of indoor units 40 (40a, 40b), a liquid side communication pipe La and a gas side communication pipe Ga, and a plurality of refrigerant leakage sensors 60 (60a, 60b). A plurality of remote controllers 65 (65a, 65b) and a controller 70 for controlling the operation of the air conditioning system 100 are provided.

  In the air conditioning system 100, the refrigerant circuit RC is configured by connecting the outdoor unit 10 and the indoor unit 40 via the liquid side communication pipe La and the gas side communication pipe Ga. In the air conditioning system 100, the refrigerant circuit RC performs a refrigeration cycle in which the refrigerant is compressed, cooled or condensed, decompressed, heated or evaporated, and then compressed again. In the present embodiment, the refrigerant circuit RC is filled with slightly flammable R32 as a refrigerant for performing a vapor compression refrigeration cycle.

  The refrigerant circuit RC is mainly connected to the outdoor circuit RC1 configured in the outdoor unit 10, the indoor circuit RC2 configured in each indoor unit 40, the outdoor circuit RC1 and each indoor circuit RC2. And a communication circuit RC3. The communication circuit RC3 includes a liquid-side communication circuit RC3a that functions as a flow path for liquid refrigerant that flows between the outdoor unit 10 and the indoor unit 40, and gas refrigerant that flows between the outdoor unit 10 and the indoor unit 40. And a gas side communication circuit RC3b that functions as a flow path.

(1-1) Outdoor unit 10
The outdoor unit 10 is disposed outdoors. The outdoor unit 10 is connected to the plurality of indoor units 40 via the liquid side communication pipe La and the gas side communication pipe Ga, and constitutes a part of the refrigerant circuit RC (outdoor circuit RC1).

  The outdoor unit 10 mainly includes a plurality of refrigerant pipes (first pipe P1 to eleventh pipe P11), a compressor 11, an accumulator 12, and a four-way switching valve 13, as devices constituting the outdoor circuit RC1. The outdoor heat exchanger 14, the supercooler 15, the outdoor first electric valve 16, the outdoor second electric valve 17, the liquid side closing valve 19, and the gas side closing valve 20 are provided.

  The first pipe P1 connects the gas side shut-off valve 20 and the first port of the four-way switching valve 13. The second pipe P <b> 2 connects the inlet port of the accumulator 12 and the second port of the four-way switching valve 13. The third pipe P3 connects the outlet port of the accumulator 12 and the suction port of the compressor 11. The fourth pipe P4 connects the discharge port of the compressor 11 and the third port of the four-way switching valve 13. The fifth pipe P5 connects the fourth port of the four-way switching valve 13 and the gas side inlet / outlet of the outdoor heat exchanger 14. The sixth pipe P6 connects the liquid side inlet / outlet of the outdoor heat exchanger 14 and one end of the outdoor first electric valve 16. The seventh pipe P7 connects the other end of the outdoor first electric valve 16 and one end of the main flow path 151 of the subcooler 15. The eighth pipe P <b> 8 connects the other end of the main flow path 151 of the subcooler 15 and one end of the liquid side shut-off valve 19. The ninth pipe P9 connects a portion between both ends of the sixth pipe P6 and one end of the outdoor second electric valve 17. The tenth pipe P <b> 10 connects the other end of the outdoor second motor operated valve 17 and one end of the sub flow path 152 of the subcooler 15. The eleventh pipe P11 connects the other end of the sub flow path 152 of the subcooler 15 and a portion between both ends of the first pipe P1. Note that these refrigerant pipes (P1-P11) may actually be constituted by a single pipe, or may be constituted by connecting a plurality of pipes via joints or the like.

  The compressor 11 is a device that compresses a low-pressure refrigerant in the refrigeration cycle until it reaches a high pressure. In the present embodiment, the compressor 11 has a hermetic structure in which a displacement type compression element such as a rotary type or a scroll type is rotationally driven by a compressor motor (not shown). Here, the compressor motor can control the operation frequency by an inverter, and thus the capacity of the compressor 11 can be controlled.

  The accumulator 12 is a container for suppressing the liquid refrigerant from being excessively sucked into the compressor 11. The accumulator 12 has a predetermined volume according to the amount of refrigerant charged in the refrigerant circuit RC.

  The four-way switching valve 13 is a flow path switching valve for switching the refrigerant flow in the refrigerant circuit RC. The four-way switching valve 13 can be switched between a forward cycle state and a reverse cycle state. When the four-way switching valve 13 is in the normal cycle state, the first port (first pipe P1) and the second port (second pipe P2) are communicated with each other, and the third port (fourth pipe P4) and the fourth port are connected. (5th piping P5) is connected (refer the continuous line of the four-way selector valve 13 of FIG. 1). When the four-way switching valve 13 enters the reverse cycle state, the first port (first pipe P1) and the third port (fourth pipe P4) communicate with each other, and the second port (second pipe P2) and the fourth port. (5th piping P5) is connected (refer the broken line of the four-way selector valve 13 of FIG. 1).

  The outdoor heat exchanger 14 is a heat exchanger that functions as a refrigerant condenser (or radiator) or an evaporator. The outdoor heat exchanger 14 functions as a refrigerant condenser during normal cycle operation (operation in which the four-way switching valve 13 is in the normal cycle state). The outdoor heat exchanger 14 functions as a refrigerant evaporator during reverse cycle operation (operation in which the four-way switching valve 13 is in the reverse cycle state). The outdoor heat exchanger 14 includes a plurality of heat transfer tubes and heat transfer fins (not shown). The outdoor heat exchanger 14 is configured so that heat exchange is performed between the refrigerant in the heat transfer tube and the air passing through the periphery of the heat transfer tube or the heat transfer fin (the outdoor air flow described later). .

  The subcooler 15 is a heat exchanger that uses an inflowing refrigerant as a supercooled liquid refrigerant. The subcooler 15 is, for example, a double pipe heat exchanger, and the main channel 151 and the sub channel 152 are configured in the subcooler 15. The subcooler 15 is configured such that the refrigerant flowing through the main flow channel 151 and the sub flow channel 152 performs heat exchange.

  The outdoor first electric valve 16 is an electric valve capable of opening degree control, and depressurizes or adjusts the flow rate of the refrigerant flowing in accordance with the opening degree. The outdoor first electric valve 16 can be switched between an open state and a closed state. The outdoor first electric valve 16 is disposed between the outdoor heat exchanger 14 and the supercooler 15 (main flow path 151).

  The outdoor second motor-operated valve 17 is a motor-operated valve capable of opening degree control, and depressurizes or adjusts the flow rate of the refrigerant flowing in accordance with the opening degree. The outdoor second electric valve 17 can be switched between an open state and a closed state. The outdoor second electric valve 17 is disposed between the outdoor heat exchanger 14 and the supercooler 15 (sub-flow path 152).

  The liquid side shut-off valve 19 is a manual valve arranged at the connection portion between the eighth pipe P8 and the liquid side connecting pipe La. The liquid side shut-off valve 19 has one end connected to the eighth pipe P8 and the other end connected to the liquid side connecting pipe La.

  The gas side shut-off valve 20 is a manual valve disposed at a connection portion between the first pipe P1 and the gas side communication pipe Ga. The gas side shut-off valve 20 has one end connected to the first pipe P1 and the other end connected to the gas side communication pipe Ga.

  The outdoor unit 10 also has an outdoor fan 25 that generates an outdoor air flow that passes through the outdoor heat exchanger 14. The outdoor fan 25 is a blower that supplies an outdoor air flow as a cooling source or a heating source of the refrigerant flowing through the outdoor heat exchanger 14 to the outdoor heat exchanger 14. The outdoor fan 25 includes an outdoor fan motor (not shown) as a drive source, and the start and stop and the number of rotations are appropriately controlled according to the situation.

  Further, the outdoor unit 10 is provided with a plurality of outdoor sensors 26 (see FIG. 4) for detecting the state (mainly pressure or temperature) of the refrigerant in the refrigerant circuit RC. The outdoor sensor 26 is a pressure sensor, a temperature sensor such as a thermistor or a thermocouple. Examples of the outdoor sensor 26 include a suction pressure sensor that detects a suction pressure that is a refrigerant pressure on the suction side of the compressor 11, and a discharge pressure sensor that detects a discharge pressure that is a refrigerant pressure on the discharge side of the compressor 11. And a temperature sensor for detecting the temperature of the refrigerant in the outdoor heat exchanger 14.

  The outdoor unit 10 also has an outdoor unit control unit 30 that controls the operation and state of each device included in the outdoor unit 10. The outdoor unit control unit 30 includes a microcomputer having a CPU, a memory, and the like. The outdoor unit control unit 30 is electrically connected to each device (11, 13, 16, 17, 25, etc.) included in the outdoor unit 10 and the outdoor sensor 26, and inputs / outputs signals to / from each other. Moreover, the outdoor unit control part 30 transmits / receives a control signal etc. separately via the indoor unit control part 48 (after-mentioned) and remote control 65 of each indoor unit 40 via the communication line cb.

(1-2) Indoor unit 40
Each indoor unit 40 is connected to the outdoor unit 10 via the liquid side communication pipe La and the gas side communication pipe Ga. Each indoor unit 40 is arranged in parallel with the other indoor units 40 with respect to the outdoor unit 10. Each indoor unit 40 is arranged in the target space and constitutes a part of the refrigerant circuit RC (indoor side circuit RC2). Each of the indoor units 40 mainly includes a plurality of refrigerant pipes (17th pipe P17 to 18th pipe P18) and an indoor expansion valve 41 (“motorized valve” described in the claims) as devices constituting the indoor circuit RC2. And an indoor heat exchanger 42.

  The seventeenth pipe P17 connects the liquid side communication pipe La and the liquid side refrigerant inlet / outlet of the indoor heat exchanger 42. The eighteenth pipe P18 connects the gas side refrigerant inlet / outlet of the indoor heat exchanger 42 and the gas side communication pipe Ga. Note that these refrigerant pipes (P17 to P18) may actually be configured by a single pipe, or may be configured by connecting a plurality of pipes via joints or the like.

  The indoor expansion valve 41 is an electric valve capable of controlling the opening degree, and depressurizes or adjusts the flow rate of the refrigerant flowing in accordance with the opening degree. The indoor expansion valve 41 can be switched between an open state and a closed state. The indoor expansion valve 41 is disposed on the seventeenth pipe P <b> 17 and is located between the liquid side communication pipe La and the indoor heat exchanger 42.

  The indoor heat exchanger 42 is a heat exchanger that functions as a refrigerant evaporator or condenser (or radiator). The indoor heat exchanger 42 functions as a refrigerant evaporator during the normal cycle operation. The indoor heat exchanger 42 functions as a refrigerant condenser during reverse cycle operation. The indoor heat exchanger 42 includes a plurality of heat transfer tubes and heat transfer fins (not shown). The indoor heat exchanger 42 is configured such that heat exchange is performed between the refrigerant in the heat transfer tube and the air passing through the periphery of the heat transfer tube or the heat transfer fin (the indoor airflow described later). .

  The indoor unit 40 has an indoor fan 45 for sucking air in the target space, passing the air through the indoor heat exchanger 42 and exchanging heat with the refrigerant, and then sending it to the target space again. The indoor fan 45 is disposed in the target space. The indoor fan 45 includes an indoor fan motor (not shown) that is a drive source. The indoor fan 45 generates an indoor air flow as a heating source or a cooling source of the refrigerant flowing through the indoor heat exchanger 42 when driven.

  The indoor unit 40 is provided with an indoor side sensor 46 (see FIG. 4) for detecting the state (mainly pressure or temperature) of the refrigerant in the refrigerant circuit RC. The indoor side sensor 46 is a temperature sensor such as a pressure sensor, a thermistor, or a thermocouple. The indoor side sensor 46 includes, for example, a temperature sensor that detects the temperature of the refrigerant in the indoor heat exchanger 42, a pressure sensor that detects the pressure of the refrigerant in the indoor side circuit RC2, and the like.

  The indoor unit 40 also has an indoor unit control unit 48 that controls the operation / state of each device included in the indoor unit 40. The indoor unit control unit 48 includes a microcomputer including a CPU and a memory. The indoor unit control unit 48 is electrically connected to the devices (41, 45) included in the indoor unit 40 and the indoor side sensor 46, and inputs and outputs signals to and from each other. The indoor unit controller 48 is connected to the outdoor unit controller 30 and the remote controller 65 via the communication line cb, and transmits and receives control signals and the like.

(1-3) Liquid side communication pipe La, gas side connection pipe Ga
The liquid side connection pipe La and the gas side connection pipe Ga are refrigerant connection pipes that connect the outdoor unit 10 and the indoor units 40, and are constructed on site. The pipe lengths and pipe diameters of the liquid side connection pipe La and the gas side connection pipe Ga are appropriately selected according to the design specifications and the installation environment.

  The liquid side communication pipe La constitutes a liquid side communication circuit RC3 (liquid side communication circuit RC3a) between the outdoor unit 10 and each indoor unit 40, and is a pipe through which high-pressure or intermediate-pressure refrigerant flows during operation. The liquid side connection pipe La is configured by connecting a plurality of pipes, joints, and the like. Specifically, the liquid side connecting pipe La includes a first liquid side connecting pipe L1, a second liquid side connecting pipe L2, a third liquid side connecting pipe L3, and a branch portion BP (liquid side branch portion BPa). . The first liquid side connecting pipe L1, the second liquid side connecting pipe L2, and the third liquid side connecting pipe L3 may actually be constituted by a single pipe, or a plurality of pipes may be connected via joints or the like. It may be configured by connecting the pipes.

  One end of the first liquid side connecting pipe L1 is connected to the liquid side shut-off valve 19 of the outdoor unit 10, and the outdoor unit is more than the second liquid side connecting pipe L2, the third liquid side connecting pipe L3, and the liquid side branch portion BPa. 10 side. The second liquid side connecting pipe L2 and the third liquid side connecting pipe L3 are connected to the indoor unit 40 corresponding to one end. In the present embodiment, the second liquid side connecting pipe L2 corresponds to the indoor unit 40a, and the third liquid side connecting pipe L3 corresponds to the indoor unit 40b. The second liquid side connecting pipe L2 and the third liquid side connecting pipe L3 are arranged in parallel with each other. The first liquid side connecting pipe L1, the second liquid side connecting pipe L2, and the third liquid side connecting pipe L3 are connected and communicated at the liquid side branch portion BPa.

  The gas side communication pipe Ga constitutes a gas side communication circuit RC3 (gas side communication circuit RC3b) between the outdoor unit 10 and each indoor unit 40, and is a pipe through which a low-pressure refrigerant flows during operation. The gas side communication pipe Ga is configured by connecting a plurality of pipes, joints, and the like. The gas side connecting pipe Ga includes a first gas side connecting pipe G1, a second gas side connecting pipe G2, a third gas side connecting pipe G3, and a branch part BP (gas side branch part BPb). The first gas side connecting pipe G1, the second gas side connecting pipe G2, and the third gas side connecting pipe G3 may actually be constituted by a single pipe or a plurality of joints via joints or the like. You may comprise by connecting piping.

  One end of the first gas side connection pipe G1 is connected to the gas side shutoff valve 20 of the outdoor unit 10, and the outdoor unit is more than the second gas side connection pipe G2, the third gas side connection pipe G3, and the gas side branch portion BPb. 10 side. The second gas side connecting pipe G2 and the third gas side connecting pipe G3 are connected to the indoor unit 40 corresponding to one end. In the present embodiment, the second gas side communication pipe G2 corresponds to the indoor unit 40a, and the third gas side communication pipe G3 corresponds to the indoor unit 40b. The second gas side connecting pipe G2 and the third gas side connecting pipe G3 are arranged in parallel to each other. The first gas side connecting pipe G1, the second gas side connecting pipe G2, and the third gas side connecting pipe G3 are connected and communicated with each other at the gas side branch portion BPb.

  In the following description, one or both of the liquid side communication pipe La and the gas side communication pipe Ga are referred to as “refrigerant communication pipe”. One or both of the first liquid side communication pipe L1 and the first gas side communication pipe G1 are referred to as “one end side connection pipe”. Further, any / all of the second liquid side connecting pipe L2, the third liquid side connecting pipe L3, the second gas side connecting pipe G2, and the third gas side connecting pipe G3 are referred to as “other end side connecting pipe”.

  The branch part BP (liquid side branch part BPa, gas side branch part BPb) included in the refrigerant communication pipe flows from the outdoor unit 10 side (that is, the first liquid side connection pipe L1 or the first gas side connection pipe G1 side). And the indoor unit 40 side (that is, the second liquid side connecting pipe L2 or the third liquid side connecting pipe L3, or the second gas side connecting pipe G2 or the third gas side connecting pipe G3 side). It is the part where the refrigerant flowing from

  Each branch portion BP includes an outdoor unit side connection pipe 81, a plurality of indoor unit side connection pipes 82, a branch pipe 83, and a shut-off valve 84, respectively. In the branch portion BP, the outdoor unit side connection pipe 81 and each indoor unit side connection pipe 82 are connected via the branch pipe 83 and communicated with each other.

  The outdoor unit side connecting pipe 81 (corresponding to “outside pipe” described in the claims) is located closer to the outdoor unit 10 than the branch pipe 83, one end is connected to one end side connecting pipe, and the other end is branched. It is connected to the tube 83.

  Each indoor unit side connecting pipe 82 (corresponding to “indoor side piping” in the claims) is located closer to the indoor unit 40 than the branch pipe 83. Each indoor unit side connecting pipe 82 has a one-to-one correspondence with one of the other end side connecting pipes, and is connected to the corresponding other end side connecting pipe.

  The branch pipe 83 (corresponding to the “branch portion” described in the claims) has one end connected to the outdoor unit side connection pipe 81 and the other end branched in two, and any one of the indoor units at each branch destination. It is connected to the side connection pipe 82.

  The shut-off valve 84 (corresponding to a “control valve” described in the claims) is a valve that allows the flow of the refrigerant when it is opened and shuts off the flow of the refrigerant when it is closed. The shut-off valve 84 is disposed on the outdoor unit side connecting pipe 81. In the present embodiment, the shut-off valve 84 is a valve that can be switched between a closed state and an open state by being supplied with a predetermined drive voltage, and is a commonly used electromagnetic valve. The operation (opening / closing) of the shut-off valve 84 is directly controlled by the electrical component unit 52 and is comprehensively controlled by the controller 70.

  In the air conditioning system 100, the branch portion BP is constituted by the branch pipe unit 50. Specifically, the liquid side branch portion BPa is constituted by the first branch pipe unit 50a, and the gas side branch portion BPb is constituted by the second branch pipe unit 50b. Details of the branch pipe unit 50 will be described later.

(1-4) Refrigerant leakage sensor 60
The refrigerant leakage sensor 60 is a sensor for detecting refrigerant leakage in a target space in which the indoor unit 40 is disposed (more specifically, in the indoor unit 40). In the present embodiment, a known general-purpose product is used for the refrigerant leak sensor 60 in accordance with the type of refrigerant enclosed in the refrigerant circuit RC. The refrigerant leakage sensor 60 is disposed in the target space. More specifically, the refrigerant leakage sensor 60 is associated with the indoor unit 40 on a one-to-one basis, and is disposed in the corresponding indoor unit 40.

  The refrigerant leak sensor 60 outputs an electric signal (refrigerant leak sensor detection signal) corresponding to the detected value to the controller 70 continuously or intermittently. More specifically, the voltage of the refrigerant leak sensor detection signal output from the refrigerant leak sensor 60 changes according to the concentration of the refrigerant detected by the refrigerant leak sensor 60. In other words, the refrigerant leak sensor detection signal includes the refrigerant leak concentration in the target space where the refrigerant leak sensor 60 is installed (more specifically, the refrigerant detected by the refrigerant leak sensor 60 in addition to the presence or absence of refrigerant leak in the refrigerant circuit RC). Is output to the controller 70 in such a manner that it can be specified. That is, the refrigerant leak sensor 60 is a “refrigerant leak detection unit” that detects refrigerant leak in the indoor circuit RC2 by directly detecting the refrigerant flowing out of the indoor circuit RC2 (more specifically, the refrigerant concentration). Equivalent to.

(1-5) Remote control 65
The remote controller 65 is an input device for the user to input various commands for switching the operating state of the air conditioning system 100. For example, the remote controller 65 is input by the user with a command for switching the start / stop of the indoor unit 40, the set temperature, and the like.

  The remote controller 65 also functions as a display device for displaying various information to the user. For example, the remote controller 65 displays the operating state (set temperature, etc.) of the indoor unit 40. Further, for example, when the refrigerant leaks, the remote controller 65 displays information (refrigerant leakage notification information) for notifying the administrator of the fact that the refrigerant is leaking and corresponding processing related thereto.

  The remote controller 65 is connected to the controller 70 (more specifically, the corresponding indoor unit controller 48) via the communication line cb, and transmits and receives signals to and from each other. The remote controller 65 transmits a command input by the user to the controller 70 via the communication line cb. In addition, the remote controller 65 displays information in response to an instruction received via the communication line cb.

(1-6) Controller 70
The controller 70 is a computer that controls the operation of the air conditioning system 100 by controlling the state of each device. In the present embodiment, the controller 70 is configured by connecting the outdoor unit control unit 30 and the indoor unit control unit 48 in each indoor unit 40 via a communication line cb. Details of the controller 70 will be described later.

(2) Flow of refrigerant in refrigerant circuit RC Hereinafter, the flow of refrigerant in the refrigerant circuit RC will be described. In the air conditioning system 100, a forward cycle operation and a reverse cycle operation are mainly performed. Here, the low pressure in the refrigeration cycle is the pressure of refrigerant sucked by the compressor 11 (suction pressure), and the high pressure in the refrigeration cycle is the pressure of refrigerant discharged from the compressor 11 (discharge pressure).

(2-1) Refrigerant flow during forward cycle operation During forward cycle operation (cooling operation, etc.), the four-way switching valve 13 is controlled to the forward cycle state, and the refrigerant charged in the refrigerant circuit RC is mainly the outdoor side. Circuit RC1 (compressor 11, outdoor heat exchanger 14, outdoor first electric valve 16, and subcooler 15), liquid side communication circuit RC3a (first liquid side communication pipe L1, liquid side branch portion BPa, second liquid Side communication pipe L2 and / or third liquid side communication pipe L3), indoor side circuit RC2 (indoor expansion valve 41 and indoor heat exchanger 42) of the indoor unit 40 in operation, gas side communication circuit RC3b (first gas side) The communication pipe G1, the gas side branch portion BPb, the second gas side connection pipe G2 and / or the third gas side connection pipe G3), and the compressor 11 are circulated in this order. During normal cycle operation, in the outdoor circuit RC1, a part of the refrigerant flowing through the sixth pipe P6 branches to the ninth pipe P9 and passes through the outdoor second electric valve 17 and the subcooler 15 (sub-flow path 152). After that, it is returned to the compressor 11.

  Specifically, when the normal cycle operation is started, the refrigerant is sucked into the compressor 11 and compressed after being compressed in the outdoor circuit RC1. In the compressor 11, capacity control is performed according to the thermal load required by the indoor unit 40 during operation. Specifically, the target value of the suction pressure is set according to the thermal load required by the indoor unit 40, and the operating frequency of the compressor 11 is controlled so that the suction pressure becomes the target value. The gas refrigerant discharged from the compressor 11 flows into the outdoor heat exchanger 14.

  The gas refrigerant flowing into the outdoor heat exchanger 14 performs heat exchange with the outdoor air flow sent by the outdoor fan 25 in the outdoor heat exchanger 14 to dissipate heat and condense. The refrigerant flowing out of the outdoor heat exchanger 14 branches in the process of flowing through the sixth pipe P6.

  One refrigerant branched in the process of flowing through the sixth pipe P6 flows into the outdoor first electric valve 16 and is depressurized or adjusted in flow rate according to the opening degree of the outdoor first electric valve 16, and then the subcooler 15 It flows into the main channel 151. The refrigerant that has flowed into the main flow path 151 of the subcooler 15 exchanges heat with the refrigerant flowing through the sub flow path 152 and is further cooled to become a supercooled liquid refrigerant. The liquid refrigerant that has flowed out of the main channel 151 of the subcooler 15 flows out of the outdoor circuit RC1 and flows into the indoor circuit RC2 of the indoor unit 40 that is in operation through the liquid side communication circuit RC3a.

  The other refrigerant branched in the process of flowing through the sixth pipe P6 flows into the outdoor second electric valve 17, and after the pressure is reduced or adjusted in accordance with the opening degree of the outdoor second electric valve 17, the subcooler 15 It flows into the sub flow path 152. The refrigerant flowing into the sub flow path 152 of the subcooler 15 exchanges heat with the refrigerant flowing through the main flow path 151, and then merges with the refrigerant flowing through the first pipe P1 via the eleventh pipe P11.

  The refrigerant that has flowed into the indoor side circuit RC2 of the indoor unit 40 during operation flows into the indoor expansion valve 41, and is depressurized to a low pressure in the refrigeration cycle in accordance with the opening of the indoor expansion valve 41. Flow into the vessel 42.

  The refrigerant that has flowed into the indoor heat exchanger 42 evaporates by exchanging heat with the indoor air flow sent by the indoor fan 45, becomes a gas refrigerant, and flows out of the indoor heat exchanger 42. The gas refrigerant that has flowed out of the indoor heat exchanger 42 flows out of the indoor circuit RC2.

  The refrigerant that has flowed out of the indoor circuit RC2 flows into the outdoor unit 10 through the gas communication circuit RC3b. The refrigerant that has flowed into the outdoor unit 10 flows through the first pipe P1, flows into the accumulator 12 through the four-way switching valve 13 and the second pipe P2. The refrigerant flowing into the accumulator 12 is temporarily stored and then sucked into the compressor 11 again.

(2-2) Flow of refrigerant during reverse cycle operation During reverse cycle operation (heating operation, etc.), the four-way switching valve 13 is controlled to the reverse cycle state, and the refrigerant charged in the refrigerant circuit RC is mainly used as a compressor. 11. Gas side communication circuit RC3b, operating indoor unit 40 (indoor heat exchanger 42 and indoor expansion valve 41), liquid side communication circuit RC3a, supercooler 15, outdoor first electric valve 16, outdoor heat exchanger 14 The compressor 11 is circulated in this order.

  Specifically, when the reverse cycle operation is started, the refrigerant is sucked into the compressor 11 and compressed after being compressed in the outdoor circuit RC1. In the compressor 11, capacity control is performed according to the thermal load required by the indoor unit 40 during operation. The gas refrigerant discharged from the compressor 11 flows out of the outdoor circuit RC1 through the fourth pipe P4 and the first pipe P1, and flows into the indoor circuit RC2 of the operating indoor unit 40 through the gas communication circuit RC3b. To do.

  The refrigerant that has flowed into the indoor circuit RC2 flows into the indoor heat exchanger 42, and is condensed by exchanging heat with the indoor airflow sent by the indoor fan 45. The refrigerant that has flowed out of the indoor heat exchanger 42 flows into the indoor expansion valve 41, is decompressed to a low pressure in the refrigeration cycle according to the opening of the indoor expansion valve 41, and then flows out of the indoor circuit RC <b> 2.

  The refrigerant that has flowed out of the indoor circuit RC2 flows into the outdoor circuit RC1 through the liquid side communication circuit RC3a. The refrigerant flowing into the outdoor circuit RC1 passes through the eighth pipe P8, the supercooler 15 (main flow path 151), the seventh pipe P7, the outdoor first electric valve 16 and the sixth pipe P6, and then the outdoor heat exchanger 14. Flows into the liquid side inlet / outlet.

  The refrigerant flowing into the outdoor heat exchanger 14 evaporates by exchanging heat with the outdoor air flow sent by the outdoor fan 25 in the outdoor heat exchanger 14. The refrigerant flowing out from the gas side inlet / outlet of the outdoor heat exchanger 14 flows into the accumulator 12 through the fifth pipe P5, the four-way switching valve 13, and the second pipe P2. The refrigerant flowing into the accumulator 12 is temporarily stored and then sucked into the compressor 11 again.

(3) Details of the branch pipe unit 50 The branch pipe unit 50 is a unit for constituting a branch portion BP (corresponding to a “first portion” described in claims) in the communication circuit RC3. Further, the branch pipe unit 50 has a refrigerant flow (mainly from the outdoor circuit RC1 side) between the outdoor circuit RC1 and the indoor circuit RC2 when refrigerant leakage occurs in the refrigerant circuit RC (particularly the indoor circuit RC2). It is also a unit for constituting a blocking part that blocks the flow of the refrigerant toward the indoor circuit RC2 side.

  In the refrigerant circuit RC, as the branch pipe unit 50, a first branch pipe unit 50a arranged in the liquid side connection circuit RC3a and a second branch pipe unit 50b arranged in the gas side communication circuit RC3b are arranged. Yes.

  The first branch pipe unit 50a is included in the liquid side communication pipe La. The first branch pipe unit 50a is disposed between the first liquid side connecting pipe L1, the second liquid side connecting pipe L2, and the third liquid side connecting pipe L3, and connects the two. That is, the first branch pipe unit 50a includes a first liquid side connecting pipe L1 arranged on the outdoor unit 10 side, a second liquid side connecting pipe L2 and a third liquid side connecting pipe L3 arranged on the indoor unit 40 side. And connect. The first branch pipe unit 50a constitutes a branch portion BP (liquid side branch portion BPa) in the liquid side communication circuit RC3a. The first branch pipe unit 50a includes a refrigerant flowing from the outdoor unit 10 side to the indoor unit 40 side through the first liquid side connecting pipe L1, the second liquid side connecting pipe L2, and the third liquid side connecting pipe L3, and the second A refrigerant flow path common to both the refrigerant flowing from the indoor unit 40 to the outdoor unit 10 through the liquid side communication pipe L2, the third liquid side connection pipe L3, and the first liquid side connection pipe L1 is formed.

  The second branch pipe unit 50b is included in the gas side communication pipe Ga. The second branch pipe unit 50b is arranged between the first gas side communication pipe G1, the second gas side connection pipe G2, and the third gas side connection pipe G3, and connects the two. That is, the second branch pipe unit 50b includes a first gas side communication pipe G1 disposed on the outdoor unit 10 side, a second gas side communication pipe G2 and a third gas side communication pipe G3 disposed on the indoor unit 40 side. And connect. The second branch pipe unit 50b constitutes a branch portion BP (gas side branch portion BPb) in the gas side communication circuit RC3b. The second branch pipe unit 50b includes a refrigerant flowing from the outdoor unit 10 side to the indoor unit 40 side through the first gas side communication pipe G1, the second gas side connection pipe G2, and the third gas side connection pipe G3, and the second A refrigerant flow path common to both the refrigerant flowing from the indoor unit 40 to the outdoor unit 10 through the gas side communication pipe G2, the third gas side connection pipe G3, and the first gas side communication pipe G1 is formed.

  Hereinafter, a detailed configuration of the branch pipe unit 50 will be described. In the following description, “joining” of each part is appropriately selected as “joining method” according to the installation environment and design specifications. The “joining method” is not particularly limited, and for example, brazing connection, flare connection, flange connection, or the like is assumed. Further, the following description is common to the first branch pipe unit 50a and the second branch pipe unit 50b unless otherwise specified.

  FIG. 2 is a schematic configuration diagram of the main unit 51. FIG. 3 is a schematic diagram illustrating an example of an installation mode of the branch pipe unit 50. The branch pipe unit 50 mainly includes a main body unit 51, an electrical component unit 52 and an electric wire 53.

(3-1) Main unit 51
The main unit 51 is a part of the branch pipe unit 50 that constitutes the communication circuit RC3 and forms the refrigerant flow path (branch part BP). The main unit 51 is carried into the construction site in a state assembled in advance at a factory or the like, and is connected to other piping. The main unit 51 includes the above-described outdoor unit side connection pipe 81, a plurality (here, two) of indoor unit side connection pipes 82, a branch pipe 83, and a shut-off valve 84. The outdoor unit side connection pipe 81, each indoor unit side connection pipe 82, the branch pipe 83, and the cutoff valve 84 are integrally configured in the main body unit 51.

(3-1-1) Outdoor unit side connection pipe 81
The outdoor unit side connecting pipe 81 is a tubular portion extending along a predetermined extending direction (x direction in FIG. 3). The outdoor unit side connecting pipe 81 communicates with the one end side connecting pipe to form a refrigerant flow path. The outdoor unit side connecting pipe 81 has one end (end on the one end side connecting pipe side) joined to the shut-off valve 84 and the other end (end on the other end side connecting pipe side) joined to the branch pipe 83. Yes.

  The outdoor unit side connecting pipe 81 is connected to the outdoor unit 10 from the indoor unit 40 via the indoor unit side connecting pipe 82 and the refrigerant flowing from the outdoor unit 10 side to the indoor unit 40 side via the indoor unit side connecting pipe 82 in the communication circuit RC3. A common refrigerant flow path is formed for both the refrigerant flowing into the refrigerant.

  In the present embodiment, the outdoor unit side connecting pipe 81 is made of the same copper as the one end side connecting pipe. In addition, about the cross-sectional area and length dimension of the outdoor unit side connection pipe 81, it selects suitably according to design specifications (for example, the diameter of the one end side connection piping connected, etc.) and installation environment.

(3-1-2) Indoor unit side connecting pipe 82
Each indoor unit side connecting pipe 82 is a tubular portion extending substantially parallel to the other indoor unit side connecting pipe 82. Here, “substantially parallel” means not only the case where each indoor unit side connecting pipe 82 is completely parallel, but also the extension direction of each indoor unit side connecting pipe 82 is slightly (for example, 30 degrees horizontally or vertically). Including the case where it is different. The same applies to other parts in this specification.

  Each indoor unit side connecting pipe 82 is associated with one of the other end side connecting pipes on a one-to-one basis, and communicates with the corresponding other end side connecting pipe to form a refrigerant flow path. The longitudinal direction (extending direction) of each indoor unit side connecting pipe 82 extends in the opposite direction to the outdoor unit side connecting pipe 81 along the same direction as the longitudinal direction (extending direction) of the outdoor unit side connecting pipe 81. ing. Here, “substantially the same” means not only when the longitudinal direction of the indoor unit side connecting pipe 82 and the longitudinal direction of the outdoor unit side connecting pipe 81 completely coincide, but also slightly (for example, in the horizontal direction or the vertical direction). (Including within 30 degrees). The same applies to other parts in this specification.

  The indoor unit side connecting pipe 82 has one end (end on the one end side connecting pipe side) joined to the branch pipe 83 and the other end joined to the corresponding other end side connecting pipe. In this embodiment, the indoor unit side connecting pipe 82 is made of the same copper as the corresponding other end side connecting pipe. In addition, about the cross-sectional area and length dimension of each indoor unit side connection pipe 82, it selects individually according to design specifications (for example, diameter of the other end side connection piping etc.) and installation environment.

(3-1-3) Branch pipe 83
The branch pipe 83 is located between the outdoor unit side connecting pipe 81 and each indoor unit side connecting pipe 82 and connects the two. The branch pipe 83 allows the outdoor unit side connecting pipe 81 and the corresponding indoor unit side connecting pipes 82 to communicate with each other individually. The branch pipe 83 branches the refrigerant flowing from the outdoor unit side connecting pipe 81 side and sends it to each indoor unit side connecting pipe 82, or joins the refrigerant flowing from each indoor unit side connecting pipe 82 side to the outdoor unit side This corresponds to a junction that is sent to the connecting pipe 81.

  The branch pipe 83 is connected to the branch pipe body 830, the first insertion part 831 to which the outdoor unit side connection pipe 81 is joined, and a plurality of (indoor unit side connection pipes) to which the corresponding indoor unit side connection pipes 82 are joined. Number of second insertion portions 832).

  The branch pipe body 830 is a substantially U-shaped (bifurcated) tubular portion. The first insertion part 831 extends along the extending direction of the outdoor unit side connecting pipe 81 from the portion between both ends of the branch pipe main body part 830, and is formed with a communication port communicating with the outdoor unit side connecting pipe 81. Yes. The second insertion part 832 extends from one end or the other end of the branch pipe main body part 830 along the extending direction with the corresponding indoor unit side connection pipe 82, and communicates with the corresponding indoor unit side connection pipe 82. A communication port is formed.

  In the present embodiment, the branch pipe 83 is made of the same copper as the outdoor unit side connecting pipe 81 and the indoor unit side connecting pipe 82 to be connected. In addition, about the cross-sectional area and length dimension of the branch pipe 83 (a main-body part, the 1st insertion part 831, each 2nd insertion part 832), it is a design specification (For example, the diameter of the other end side connection piping connected, etc.) ) Or depending on the installation environment.

(3-1-4) Shut-off valve 84
The shutoff valve 84 is located between the outdoor unit side connecting pipe 81 and the one end side connecting pipe, and switches the flow of the refrigerant. The outdoor unit side connecting pipe 81 is connected to the end of the one end side connecting pipe side. From another viewpoint, it can be said that the shut-off valve 84 is disposed on the outdoor unit side connecting pipe 81.

  The shutoff valve 84 mainly includes a valve main body 840, a first pipe connection part 841, and a second pipe connection part 842.

  The valve main body 840 is a main body portion of the shutoff valve 84 and includes a valve body, a coil, and the like. Inside the valve body 840, there is formed a refrigerant flow path 840a that allows the first pipe connection portion 841 and the second pipe connection portion 842 to communicate with each other. By closing the path 840a, the closed state is established. In FIG. 2, the position of the valve body N1 in the closed state is schematically shown. As shown in FIG. 2, in the shut-off valve 84, the valve element N1 extends along the z direction (the same direction as the extending direction of the first pipe connecting portion 841). In the present embodiment, the shut-off valve 84 has a substantially L-shaped appearance, and the refrigerant flow path 840a formed therein also has a substantially L-shape.

  The first pipe connection portion 841 is a tubular portion extending from the side portion of the valve main body portion 840 along a predetermined extending direction (z direction in FIG. 2). The first pipe connection portion 841 communicates with one end of the refrigerant flow path 840a in the valve main body portion 840. One end of the first pipe connection portion 841 is joined to the side portion of the valve main body portion 840. The other end of the first pipe connecting portion 841 is joined to the one end side connecting pipe in the installed state.

  The second pipe connection portion 842 is a tubular portion extending from the bottom portion of the valve main body portion 840 along a predetermined extending direction (the x direction in FIG. 2). As described above, the shut-off valve 84 has a substantially L-shaped appearance, and the refrigerant flow path 840a formed therein also has a substantially L-shape. In this regard, the extending direction (longitudinal direction) of the second pipe connecting portion 842 and the extending direction (longitudinal direction) of the first pipe connecting portion 841 are different and intersecting directions. More specifically, the extending direction of the second pipe connecting part 842 is different from the extending direction of the first pipe connecting part 841 by approximately 90 degrees. In this regard, during normal cycle operation, the refrigerant flows from the first pipe connection portion 841 to the second pipe connection portion 842, but the valve body N1 extends along the same direction as the first pipe connection portion 841. For this reason, noise reduction when the shut-off valve 84 is controlled to be closed is promoted.

  Here, “substantially 90 degrees” is not only the case where the extending direction of the second pipe connecting portion 842 and the extending direction of the first pipe connecting portion 841 are completely different by 90 degrees, but also from 90 degrees to a predetermined range. (Including within 30 degrees).

  The second pipe connection portion 842 communicates with the other end of the refrigerant flow path 840a in the valve body portion 840. One end of the second pipe connection part 842 is joined to the bottom part of the valve main body part 840. The other end of the second pipe connection part 842 is joined to the other end of the outdoor unit side connection pipe 81 (an end part on the one end side connection pipe side). More specifically, in the second pipe connection portion 842, in the installed state, the indoor unit side connection pipes 82 are arranged along the horizontal direction, and the longitudinal direction of the indoor unit side connection pipes 82 extends along the horizontal direction. Is connected to the other end of the outdoor unit side connecting pipe 81.

(3-2) Electrical component unit 52
The electrical component unit 52 (see FIG. 3) is provided independently of the main unit 51 so as to be freely movable with respect to the main unit 51 at the construction site and to improve workability. The electrical component unit 52 is fixed by a fixture 90 (see FIG. 3) at the construction site.

  The electrical component unit 52 includes an electrical component 521 for controlling the state (opening / closing) of the shutoff valve 84 (for example, a switching unit capable of switching a current flow such as an electromagnetic relay or a switching element, a connection terminal to which power is supplied, And an input unit for inputting a signal from the controller 70. Further, the electrical component unit 52 has a substrate 522 for mounting the electrical component 521.

  Further, the electrical component unit 52 includes a unit casing 523 that accommodates the electrical component 521, the substrate 522, and the like. The unit casing 523 is a casing made of synthetic resin, for example, and has a volume that can accommodate the electrical component 521, the substrate 522, and the like. The unit casing 523 is provided with a fixing portion 524 for fixing the fixture 90. Since the unit casing 523 is assumed to be installed in a narrow space, the height dimension is configured to be smaller than the height dimension of the installation place (general ceiling space).

(3-3) Electric wire 53
The electric wire 53 (see FIG. 3) is a conducting wire for supplying a drive voltage to the shut-off valve 84. The electric wire 53 electrically connects the shut-off valve 84 and the substrate 522 (electrical component 521). The electric wire 53 is a general general-purpose product and is covered with an insulator.

  The electric wire 53 is configured to have a dimension of 1 m or more so as to increase the degree of freedom regarding the arrangement of the electrical component unit 52 at the installation location. In the present embodiment, the longitudinal dimension of the electric wire 53 is 1.2 m.

(3-4) Installation Mode of Branch Pipe Unit 50 In FIG. 3, the branch pipe unit 50 is shown installed in the ceiling space SP (the space behind the ceiling of the target space). In FIG. 3, the directions of up, down, left, and right are shown. The left-right direction corresponds to the x direction in FIG. 2, and the up-down direction corresponds to the y direction in FIG. Here, the horizontal direction is included in the horizontal direction, and the vertical direction is included in the vertical direction. In FIG. 3, the front-rear direction orthogonal to the left-right direction corresponds to the z direction in FIG. 2 and is included in the horizontal direction.

  The branch pipe unit 50 is installed together with the refrigerant communication pipe in the ceiling back space SP. The ceiling back space SP is a narrow space formed between the upper surface of the ceiling of the target space (ceiling back bottom surface C1) and the roof or the upper floor (ceiling back top surface C2). Specifically, the ceiling space SP is a space having a large horizontal dimension and a small vertical dimension.

  In the present embodiment, the main unit 51 includes the indoor unit side connecting pipes 82 arranged in the horizontal direction (here, the z direction intersecting the extending direction x), and the extending direction of each indoor unit side connecting pipe 82 and the outdoor unit side. The connecting pipe 81 is arranged in such a posture that it matches the extending direction (here, both directions are different, but both extending directions are horizontal directions). In this connection, in the ceiling space SP, the main extending direction of the other end side connecting pipe (here, the horizontal direction, that is, the horizontal direction) and the main extending direction of the one end side connecting pipe (here, the left and right direction, that is, the horizontal direction). Are substantially the same. In other words, in the ceiling space SP having a narrow vertical length, the main unit 51 includes the main extending direction of the other end side connecting pipe (here, the horizontal direction, that is, the horizontal direction) and the main extending direction of the one end side connecting pipe ( Here, they are arranged in such a posture that the left and right direction, that is, the horizontal direction) is substantially the same.

  It should be noted that this is the connection mode between the first pipe connection part 841 and the second pipe connection part 842 of the shut-off valve 84 and the outdoor unit side connection pipe 81 and each indoor unit side connection pipe 82 (in the installed state, each indoor unit side A posture in which the connecting pipes 82 are arranged along the horizontal direction and the longitudinal direction of the outdoor unit side connecting pipe 81 and each indoor unit side connecting pipe 82 can extend along the horizontal direction, that is, the first pipe of the shut-off valve 84 Realized by connecting the second pipe connecting portion 842 to the other end of the outdoor unit side connecting pipe 81 in such a posture that the connecting portion 841 extends in the front-rear direction and the second pipe connecting portion 842 extends in the left-right direction. It is possible.

  The one end side connecting pipe extends along the main extending direction (the x direction in FIG. 3) of the other end side connecting pipe, and then is in front of the connection portion with the main unit 51 (the first pipe connecting portion 841 of the shut-off valve 84). And curved toward the first pipe connection portion 841 direction (z direction) of the shutoff valve 84 and joined to the main unit 51.

  Each part of the main unit 51 (the outdoor unit side connecting pipe 81, the indoor unit side connecting pipe 82, the branch pipe 83 and the shutoff valve 84) is covered with a heat insulating material 95 for preventing condensation.

  The electrical component unit 52 is installed apart from the main unit 51. More specifically, the electrical component unit 52 is set apart from the main unit 51 within the range of the length dimension of the electric wire 53 that electrically connects the main unit 51 and the electrical component unit 52. In the present embodiment, the electrical component unit 52 is suspended from the ceiling space SP by attaching the fixture 90 fixed to the ceiling top surface C2.

  The electrical component unit 52 extends between the shut-off valve 84 of the main unit 51 and the substrate 522 (electrical component 521) of the electrical component unit 52, and electrically connects both. The electric wire 53 is connected in advance to one of the shut-off valve 84 and the main unit 51 before being installed, and is connected to the other at the site.

(4) Details of Controller 70 In the air conditioning system 100, the outdoor unit control unit 30 and the indoor unit control unit 48 are connected by the communication line cb, so that the controller 70 is configured. FIG. 4 is a block diagram schematically showing the controller 70 and each unit connected to the controller 70.

  The controller 70 has a plurality of control modes, and controls the operation of each device according to the transition control mode. In the present embodiment, the controller 70 has, as control modes, a normal operation mode that transitions during operation (when there is no refrigerant leakage) and a case where refrigerant leakage occurs (more specifically, when a leaked refrigerant is detected). And a refrigerant leakage mode that makes a transition to ().

  The controller 70 includes devices included in the air conditioning system 100 (specifically, the compressor 11, the outdoor first electric valve 16, the outdoor second electric valve 17, the outdoor fan 25, and the outdoor sensor 26 included in the outdoor unit 10). The indoor expansion valve 41, the indoor fan 45 and the indoor side sensor 46 included in each indoor unit 40, the electrical component 521 (shutoff valve 84) of each branch pipe unit 50, each refrigerant leak sensor 60, each remote controller 65, etc. ) And are electrically connected.

  The controller 70 mainly includes a storage unit 71, an input control unit 72, a mode control unit 73, a refrigerant leakage determination unit 74, a device control unit 75, a drive signal output unit 76, and a display control unit 77. Have. Each of these functional units in the controller 70 is realized by the CPU, the memory, and various electric / electronic components included in the outdoor unit control unit 30 and / or the indoor unit control unit 48 functioning integrally. Yes.

(4-1) Storage unit 71
The storage unit 71 includes, for example, a ROM, a RAM, and a flash memory, and includes a volatile storage area and a nonvolatile storage area. The storage unit 71 includes a program storage area M1 in which a control program that defines processing in each unit of the controller 70 is stored.

  The storage unit 71 includes a detection value storage area M2 for storing detection values of various sensors. In the detection value storage area M2, for example, the detection values (intake pressure, discharge pressure, discharge temperature, refrigerant temperature in the outdoor heat exchanger 14, or indoor heat exchanger 42 in the indoor heat exchanger 42) are detected by the outdoor sensor 26 and the indoor sensor 46. Refrigerant temperature etc.) is stored.

  In addition, the storage unit 71 includes a sensor signal storage area M3 for storing a refrigerant leak sensor detection signal (a detection value of the refrigerant leak sensor 60) transmitted from the refrigerant leak sensor 60. The sensor signal storage area M3 has storage areas corresponding to the number of refrigerant leakage sensors 60, and the received refrigerant leakage sensor detection signal is stored in an area corresponding to the transmission source refrigerant leakage sensor 60. The refrigerant leakage signal stored in the sensor signal storage area M3 is updated every time the refrigerant leakage signal output from the refrigerant leakage sensor 60 is received.

  In addition, the storage unit 71 includes a command storage area M4 for storing commands input to the remote controllers 65.

  The storage unit 71 is provided with a plurality of flags having a predetermined number of bits. For example, the storage unit 71 is provided with a control mode determination flag M5 that can determine the control mode in which the controller 70 is changing. The control mode determination flag M5 includes the number of bits corresponding to the number of control modes, and can be set with a bit corresponding to the transitioned control mode.

  Further, the storage unit 71 is provided with a refrigerant leak detection flag M6 for determining that a refrigerant leak in the target space has been detected. More specifically, the refrigerant leak detection flag M6 has a number of bits corresponding to the number of indoor units 40 installed, and corresponds to the indoor unit 40 (refrigerant leak unit) where refrigerant leak is assumed to have occurred. A bit can be set. That is, the refrigerant leakage detection flag M6 is configured to be able to determine which indoor unit 40 (indoor side circuit RC2) has the refrigerant leakage when the refrigerant leakage occurs in the indoor side circuit RC2. The refrigerant leakage detection flag M6 is switched by the refrigerant leakage determination unit 74.

(4-2) Input control unit 72
The input control unit 72 is a functional unit that serves as an interface for receiving signals output from each device connected to the controller 70. For example, the input control unit 72 receives signals output from the sensors (26, 46, 60) and the remote controller 65 and stores them in the corresponding storage area of the storage unit 71 or sets a predetermined flag.

(4-3) Mode control unit 73
The mode control unit 73 is a functional unit that switches the control mode. The mode control unit 73 switches the control mode to the normal operation mode at the normal time (when the refrigerant leakage detection flag M6 is not set). The mode control unit 73 switches the control mode to the refrigerant leakage mode when the refrigerant leakage detection flag M6 is set. The mode control unit 73 sets a control mode determination flag M5 in accordance with the transition control mode.

(4-4) Refrigerant leakage determination unit 74
The refrigerant leakage determination unit 74 is a functional unit that determines whether or not refrigerant leakage has occurred in the refrigerant circuit RC (indoor circuit RC2). Specifically, the refrigerant leakage determination unit 74 determines that refrigerant leakage has occurred in the refrigerant circuit RC (indoor circuit RC2) when a predetermined refrigerant leakage detection condition is satisfied, and sets the refrigerant leakage detection flag M6. .

  In the present embodiment, whether or not the refrigerant leak detection condition is satisfied is determined based on the refrigerant leak sensor detection signal in the sensor signal storage area M3. Specifically, the refrigerant leak detection condition is that a time during which a voltage value (detection value of the refrigerant leak sensor 60) related to any one of the refrigerant leak sensor detection signals is equal to or greater than a predetermined first reference value continues for a predetermined time t1 or more. Filled by. The first reference value is a value (refrigerant concentration) at which refrigerant leakage is assumed in the indoor circuit RC2. The predetermined time t1 is set to a time during which it can be determined that the refrigerant leakage sensor detection signal is not instantaneous. The refrigerant leakage determination unit 74 identifies a refrigerant leakage unit (the indoor unit 40 in which refrigerant leakage is assumed to occur) based on the refrigerant leakage sensor 60 that is the transmission source of the refrigerant leakage sensor detection signal that satisfies the refrigerant leakage detection condition. The bit corresponding to the refrigerant leakage unit is set in the refrigerant leakage detection flag M6. That is, the refrigerant leakage determination unit 74 corresponds to a “refrigerant leakage detection unit” that individually detects refrigerant leakage of each indoor circuit RC2 together with each refrigerant leakage sensor 60.

  The predetermined time t1 is appropriately set according to the type of refrigerant sealed in the refrigerant circuit RC, the specifications of each device, the installation environment, etc., and is defined in the control program. The refrigerant leakage determination unit 74 is configured to be able to measure the predetermined time t1.

  The first reference value is appropriately set according to the type, design specifications, installation environment, and the like of the refrigerant sealed in the refrigerant circuit RC, and is defined in the control program.

(4-5) Device control unit 75
The device control unit 75 controls the operation of each device (for example, 11, 13, 16, 17, 25, 41, 45, 84, etc.) included in the air conditioning system 100 according to the situation according to the control program. The device control unit 75 determines the control mode that has transitioned by referring to the control mode determination flag M5, and controls the operation of each device based on the determined control mode.

  For example, in the normal operation mode, the device control unit 75 operates the compressor 11, the outdoor fan 25, and the indoor so that the normal cycle operation or the reverse cycle operation is performed according to the set temperature, the detection value of each sensor, or the like. The rotation speed of the fan 45, the opening degree of the outdoor first electric valve 16, the opening degree of the indoor expansion valve 41, and the like are controlled in real time.

  The device control unit 75 controls the four-way switching valve 13 to the normal cycle state during the normal cycle operation, causes the outdoor heat exchanger 14 to function as a refrigerant condenser (or a radiator), and the indoor unit 40 in operation. The indoor heat exchanger 42 is caused to function as a refrigerant evaporator. In addition, during reverse cycle operation, the device control unit 75 controls the four-way switching valve 13 to be in a reverse cycle state, causing the outdoor heat exchanger 14 to function as a refrigerant evaporator and exchanging indoor heat in the indoor unit 40 during operation. The vessel 42 is caused to function as a refrigerant condenser (or radiator).

  In addition, the device control unit 75 executes the following various controls depending on the situation. The device controller 75 is configured to be able to measure time.

<Refrigerant leakage first control>
When it is assumed that refrigerant leakage has occurred in the target space (specifically, when the refrigerant leakage detection flag M6 is set), the device control unit 75 executes the first refrigerant leakage control. In the refrigerant leakage first control, the device control unit 75 controls the indoor expansion valve 41 of the refrigerant leakage unit (the indoor unit 40 in which the refrigerant leakage has occurred) to be closed. Thereby, the inflow of the refrigerant to the refrigerant leakage unit is suppressed, and further refrigerant leakage is suppressed. That is, the refrigerant leakage first control is control for suppressing refrigerant leakage in the indoor circuit RC2 when refrigerant leakage occurs, and the indoor expansion valve 41 is in a closed state when refrigerant leakage occurs. The refrigerant flowing into the indoor unit 40 is obstructed.

<Refrigerant leakage second control>
The device control unit 75 executes the refrigerant leakage second control when it is assumed that the refrigerant leakage has occurred in the target space. The device control unit 75 operates the indoor fans 45 of the indoor units 40 at the rotation speed (air flow rate) for the refrigerant leakage second control in the refrigerant leakage second control. The refrigerant leakage second control is a control for operating the indoor fan 45 at a predetermined rotational speed in order to prevent a region where the concentration of the leakage refrigerant is high in the target space from occurring locally.

  In addition, although the rotation speed of the indoor fan 45 in the refrigerant | coolant leakage 2nd control which concerns is not specifically limited, In this embodiment, it sets to the maximum rotation speed (namely, maximum airflow). Even if the refrigerant leakage occurs in the target space by the refrigerant leakage second control, the leakage refrigerant is agitated in the target space by the use-side air flow generated by the indoor fan 45 and leaked in the target space. Occurrence of a region having a dangerous value of the refrigerant concentration is suppressed.

<Refrigerant leakage third control>
When it is assumed that the refrigerant leakage has occurred in the target space, the device control unit 75 executes the third refrigerant leakage control. In the refrigerant leakage third control, the device control unit 75 controls the shut-off valve 84 of each branch portion BP to be closed in order to divide the outdoor circuit RC1 and each indoor circuit RC2. That is, the third refrigerant leakage control is a control in which, when refrigerant leakage occurs, the refrigerant flowing from the outdoor circuit RC1 to the indoor circuit RC2 of the leakage unit is blocked by the liquid side communication circuit RC3a and the gas side communication circuit RC3b. is there.

  Specifically, the device control unit 75 closes the liquid side communication circuit RC3a by controlling the shut-off valve 84 of the liquid side branch portion BPa to the closed state via the electric component 521 in the third refrigerant leakage control. In addition, in the third refrigerant leakage control, the device control unit 75 controls the shut-off valve 84 of the gas side branch portion BPb to be closed via the electrical component 521, thereby closing the gas side communication circuit RC3b. Thereby, the flow of the refrigerant from the outdoor circuit RC1 to the indoor circuit RC2 is blocked by the communication circuit RC3, and the leakage refrigerant amount in the indoor circuit RC2 is reliably suppressed.

(4-6) Drive signal output unit 76
The drive signal output unit 76 corresponds to each device (11, 13, 16, 17, 25, 41, 45, 521 (84), etc.) according to the control content of the device control unit 75. Voltage). The drive signal output unit 76 includes a plurality of inverters (not shown), and a specific device (for example, the compressor 11, the outdoor fan 25, or each indoor fan 45) is driven from the corresponding inverter. Output a signal.

(4-7) Display control unit 77
The display control unit 77 is a functional unit that controls the operation of the remote controller 65 as a display device. The display control unit 77 causes the remote controller 65 to output predetermined information in order to display information related to the driving state and situation to the user. For example, the display control unit 77 causes the remote controller 65 to display various information such as a set temperature during operation in the normal mode.

  Further, when the refrigerant leak detection flag M6 is set, the display control unit 77 causes the remote controller 65 to display the refrigerant leak notification information. Thereby, the administrator can grasp the fact that the refrigerant leakage has occurred, and can take a predetermined response.

(5) Process Flow of Controller 70 An example of the process flow of the controller 70 will be described below with reference to FIG. FIG. 5 is a flowchart showing an example of the processing flow of the controller 70. When the controller 70 is turned on, the controller 70 performs processing in a flow as shown in steps S101 to S110 in FIG. The process flow shown in FIG. 5 is an example and can be changed as appropriate. For example, the order of steps may be changed within a consistent range, some steps may be executed in parallel with other steps, and other steps may be newly added.

  In step S101, the controller 70 proceeds to step S105 when it is assumed that refrigerant leakage has occurred in the indoor circuit RC2 (that is, in the case of YES). If it is assumed that no refrigerant leakage has occurred in the indoor circuit RC2, the controller 70 proceeds to step S102.

  In step S102, the controller 70 returns to step S101 when the operation start command is not input (that is, in the case of NO). On the other hand, when the operation start command is input (that is, in the case of YES), the controller 70 proceeds to step S103.

  In step S103, the controller 70 transitions to the normal operation mode (or maintains the normal operation mode). Thereafter, the process proceeds to step S104.

  In step S104, the controller 70 performs the normal cycle operation by controlling the state of each device in real time according to the input command, the set temperature, the detection value of each sensor (26, 46), and the like. . Although not shown, the controller 70 causes the remote controller 65 to display various information such as a set temperature. Then, it returns to step S101.

  In step S105, the controller 70 transitions to the refrigerant leakage mode. Thereafter, the controller 70 proceeds to step S106.

  In step S106, the controller 70 causes the remote controller 65 to output refrigerant leakage notification information. Thereby, the administrator can grasp that the refrigerant leakage has occurred. Thereafter, the controller 70 proceeds to step S107.

  In step S107, the controller 70 executes the refrigerant leakage first control. Specifically, the controller 70 controls the indoor expansion valve 41 of the refrigerant leakage unit to be closed. Thereby, the flow of the refrigerant | coolant to the indoor side circuit RC2 of a refrigerant | coolant leakage unit is prevented, and further refrigerant | coolant leakage is suppressed. Thereafter, the controller 70 proceeds to step S108.

  In step S108, the controller 70 executes the refrigerant leakage second control. Specifically, the controller 70 drives the indoor fan 45 at a predetermined rotation speed (for example, the maximum rotation speed). Thereby, in the target space, the leaked refrigerant is agitated, and a locally dangerous concentration is suppressed. Thereafter, the controller 70 proceeds to step S109.

  In step S109, the controller 70 executes the refrigerant leakage third control. Specifically, the controller 70 closes the shutoff valve 84 of the liquid side branch portion BPa to close the liquid side communication circuit RC3a. In addition, in the third refrigerant leakage control, the device control unit 75 closes the gas side communication circuit RC3b by controlling the shutoff valve 84 of the gas side branch portion BPb to be closed. Thereby, it is suppressed that a refrigerant | coolant flows from the outdoor side circuit RC1 to the indoor side circuit RC2 of a leakage unit, and the amount of leakage refrigerant is suppressed. Thereafter, the controller 70 proceeds to step S110.

  In step S110, the controller 70 stops the compressor 11. Thereafter, the controller 70 waits until it is released by the administrator.

(6) Features (6-1)
In the air conditioning system 100 according to the above embodiment, the shutoff valve 84 that blocks the flow of the refrigerant to the plurality of indoor units 40 is disposed on the outdoor unit side connection pipe 81 (outdoor pipe), and the number of indoor units 40 is Accordingly, the increase in the number of shut-off valves 84 is suppressed. In other words, the shutoff valve 84 is arranged on the outdoor unit 10 side of each indoor unit side connecting pipe 82 (indoor side piping group) in the branch portion BP, so that when the refrigerant leaks, the outdoor unit side connecting pipe 81 (outdoor unit 10). It is possible to prevent the flow of the refrigerant flowing from the corresponding side to the corresponding indoor unit side connecting pipe 82 (the plurality of indoor units 40). For this reason, in order to ensure the safety | security regarding a refrigerant | coolant leakage, it is not necessary to arrange | position the shut-off valve 84 for every indoor unit 40, and it is suppressed that the number of the shut-off valves 84 increases according to the number of indoor units 40. .

  In addition, the refrigerant communication pipes (La, Ga) between the outdoor unit 10 and the indoor unit 40 are constructed in a narrow ceiling space SP, so that the number of shut-off valves 84 installed on the refrigerant communication pipe increases. Therefore, the increase in work time and labor required for construction is also suppressed.

  Therefore, in connection with improving the security against refrigerant leakage, cost reduction and workability improvement are promoted.

(6-2)
In the air conditioning system 100 according to the embodiment, the refrigerant communication pipe (La, Ga) includes a gas side communication pipe Ga through which a low-pressure refrigerant flows and a liquid side communication pipe La through which a high-pressure or intermediate-pressure refrigerant flows. The shutoff valve 84 is disposed on the outdoor unit side connection pipe 81 (outdoor pipe) included in the gas side communication pipe Ga.

  Here, in the outdoor unit 10 or the indoor unit 40, it is normal that an indoor expansion valve 41 (electronic expansion valve) for reducing the pressure of the refrigerant is disposed on the refrigerant flow path communicating with the liquid side communication pipe La. When the refrigerant leaks, it is possible to prevent the flow of the refrigerant flowing from the outdoor unit 10 to the indoor unit 40 via the liquid side connection pipe La by controlling the indoor expansion valve 41 to the minimum opening. On the other hand, since there are many cases in which a control valve similar to the indoor expansion valve 41 is not disposed on the refrigerant flow path communicating with the gas side communication pipe Ga, in order to ensure safety against refrigerant leakage, It is important to prevent the flow of the refrigerant toward the indoor unit 40 side.

  In the air conditioning system 100, the shutoff valve 84 is arranged on the outdoor unit side connecting pipe 81 included in the gas side communication pipe Ga, so that an increase in the number of shutoff valves 84 is suppressed, and security against refrigerant leakage is suppressed. Ensuring is promoted.

(6-3)
In the air conditioning system 100 according to the above embodiment, the shutoff valve 84 is also disposed on the outdoor unit side connection pipe 81 (outdoor pipe) included in the liquid side communication pipe La. Thus, the safety | security ensuring with respect to a refrigerant | coolant leakage is promoted especially by arrange | positioning the shut-off valve 84 also on the outdoor unit side connection pipe 81 (outdoor pipe) included in the liquid side connection pipe La.

(6-4)
In the air conditioning system 100 according to the above-described embodiment, the indoor unit 40 includes the indoor expansion valve 41, and when refrigerant leakage occurs, the indoor unit 40 is in a closed state to prevent the refrigerant flowing into the indoor unit 40. In this way, the indoor expansion valve 41 that prevents the flow of the refrigerant by being controlled to be closed when the refrigerant leakage occurs is arranged in the indoor unit 40, so that the outdoor unit 10 to the indoor unit 40 at the time of the refrigerant leakage. It is possible to cut off the flow of the refrigerant more reliably.

(6-5)
In the air conditioning system 100 according to the embodiment, the outdoor unit side connecting pipe 81 (outdoor pipe) is configured integrally with the branch pipe 83 (branch portion) and the shutoff valve 84. Thereby, installation of the shut-off valve 84 is facilitated, and an increase in work time and labor required for construction is suppressed. Therefore, in connection with improving the security against refrigerant leakage, improvement in workability is promoted.

(6-6)
In the air conditioning system 100 according to the above embodiment, the refrigerant communication pipe (La, Ga) includes the branch pipe unit 50, which is assembled in advance and connected to other pipes at the construction site. The branch pipe unit 50 includes an outdoor unit side connection pipe 81 (outdoor pipe), a branch pipe 83 (branch portion), and a shutoff valve 84 that are integrally formed.

  Thereby, the installation of the shut-off valve 84 is particularly easy, and further increases in work time and labor required for construction are further suppressed. Therefore, in connection with improving the security against refrigerant leakage, improvement in workability is promoted.

(7) Modifications The above embodiment can be appropriately modified as shown in the following modifications. Each modification may be applied in combination with another modification as long as no contradiction occurs.

(7-1) Modification 1
In the embodiment described above, the shut-off valves 84 are arranged in each of the liquid side branch portion BPa and the gas side branch portion BPb. In this respect, in order to achieve the effect of more reliably blocking the refrigerant flowing from the outdoor side circuit RC1 to the indoor side circuit RC2 at the time of refrigerant leakage and reducing the amount of refrigerant leaked, the liquid side branch part BPa and the gas side branch part BPb It is preferable that the shut-off valve 84 is arrange | positioned at both. However, the shut-off valve 84 is not necessarily arranged in both the liquid side branch portion BPa and the gas side branch portion BPb, and may be arranged only in one.

  For example, since the indoor expansion valve 41 is controlled to be closed when the refrigerant leaks, the refrigerant flowing from the outdoor circuit RC1 to the indoor circuit RC2 via the liquid communication circuit RC3a can be shut off. The shut-off valve 84 disposed in the portion BPa is not necessarily required and may be omitted as appropriate. In such a case, like the air conditioning system 100 ′ illustrated in FIG. 6, the liquid side branch portion BPa may be configured by a branch pipe unit 50 ′ that does not include the shut-off valve 84.

  Further, for example, when a valve capable of blocking the flow of the refrigerant flowing from the outdoor circuit RC1 to the indoor circuit RC2 of the leakage unit via the gas side communication circuit RC3b at the time of refrigerant leakage is arranged separately, Is controlled to be closed so that the refrigerant flowing from the outdoor circuit RC1 to the indoor circuit RC2 via the gas side communication circuit RC3b can be shut off. The shut-off valve 84 arranged at the branch portion BPb is not necessarily required and may be omitted as appropriate.

(7-2) Modification 2
In the above embodiment, the case where the shutoff valve 84 is an electromagnetic valve that can be switched between open and closed states has been described. However, the shut-off valve 84 is not necessarily limited to an electromagnetic valve, and may be another control valve. For example, the shutoff valve 84 may be an electric valve that can be adjusted in opening. In such a case, the arrangement mode of the shut-off valve 84 in the main unit 51 may be the same as that in the above embodiment, or may be changed as appropriate.

(7-3) Modification 3
In the above embodiment, the case where the branch portion BP is configured by the branch pipe unit 50 has been described. However, the branch portion BP is not necessarily constituted by the branch pipe unit 50, and the branch pipe unit 50 can be omitted as appropriate. That is, in the branch portion BP, pipes and valves (outdoor unit side connection pipe 81, indoor unit side connection pipe 82, branch pipe 83, shutoff valve 84) that are independently carried into the construction site are connected to each other at the construction site. May be configured. Even in such a case, the effects described in (6-1) above can be realized.

(7-4) Modification 4
In the above embodiment, the case where the refrigerant flow path is branched into two in the branch portion BP has been described. However, the number of branches in the branch portion BP is not particularly limited and can be changed as appropriate. For example, in the branch part BP, the refrigerant flow path may be branched into three or more. In such a case, the indoor unit side connection pipes 82 corresponding to the number of branches may be arranged in the branch portion BP, and ports corresponding to the number of the indoor unit side connection pipes 82 may be formed in the branch pipe 83.

(7-5) Modification 5
The configuration aspect of the refrigerant circuit RC in the above embodiment is not necessarily limited to the aspect illustrated in FIG. 1 and can be appropriately changed according to the design specifications and the installation environment. For example, the outdoor first electric valve 16 is not always necessary and can be omitted as appropriate. For example, the subcooler 15 and the outdoor second electric valve 17 are not necessarily required and may be omitted as appropriate. In addition, a device not shown in FIG. 1 may be newly added to the refrigerant circuit RC.

(7-6) Modification 6
In the said embodiment, the controller 70 which controls operation | movement of the air conditioning system 100 was comprised by connecting the outdoor unit control part 30 and the indoor unit control part 48 of each indoor unit 40 via the communication line cb. . However, the configuration of the controller 70 is not necessarily limited to this, and can be appropriately changed according to the design specifications and the installation environment. That is, the configuration aspect of the controller 70 is not particularly limited, and some or all of the elements included in the controller 70 are not necessarily arranged in either the outdoor unit 10 or the indoor unit 40, and other devices It may be arranged in or independently.

  For example, the controller 70 may be configured by another device such as a remote controller 65 or a centralized management device instead of / with one or both of the outdoor unit controller 30 and each indoor unit controller 48. In such a case, other devices may be arranged in a remote place connected to the outdoor unit 10 or the indoor unit 40 via a communication network.

  Further, for example, the controller 70 may be configured only by the outdoor unit control unit 30.

(7-7) Modification 7
In the above embodiment, R32 is used as the refrigerant circulating in the refrigerant circuit RC. However, the refrigerant used in the refrigerant circuit RC is not particularly limited and may be another refrigerant. For example, in the refrigerant circuit RC, and HFC-based refrigerant such as R407C and R410A, CO ₂ or ammonia may be used.

(7-8) Modification 8
In the above embodiment, the idea according to the present disclosure has been applied to the air conditioning system 100. However, the idea according to the present disclosure is not limited to this, and can be applied to other refrigeration apparatuses (for example, a water heater and a heat pump chiller) having a refrigerant circuit.

(7-9) Modification 9
In the above-described embodiment, an example in which the idea according to the present disclosure is applied to an air conditioning system 100 in which two indoor units 40 are connected in parallel to one outdoor unit 10 by connecting pipes (Ga, La). explained. However, the configuration aspect of the air conditioning system to which the idea according to the present disclosure is applied is not necessarily limited to the aspect. That is, regarding the air conditioning system to which the idea according to the present disclosure is applied, the number of outdoor units 10 and / or the indoor units 40 and their connection modes can be appropriately changed according to the installation environment and design specifications.

  For example, in an air conditioning system to which the idea according to the present disclosure is applied, a plurality of outdoor units 10 may be arranged in series or in parallel. In addition, three or more indoor units 40 may be connected to one outdoor unit 10.

  For example, the idea according to the present disclosure is that three or more indoor units 40 are connected to one outdoor unit 10 as in the air conditioning system 200 shown in FIG. And may be applied to an air conditioning system arranged in series or in parallel.

  FIG. 7 is a schematic configuration diagram of the air conditioning system 200. In FIG. 7, the liquid side communication pipe La and the gas side communication pipe Ga are shown together to simplify the illustration.

  In the air conditioning system 200, each communication pipe (La, Ga) extending between the outdoor unit 10 and each indoor unit 40 branches into a plurality (here, four in large), so that the indoor unit 40 arranged at the branch destination. A plurality (four) of groups (AD) are configured. In the air conditioning system 200, each group A-D includes a plurality of indoor units 40, respectively.

  In FIG. 7, the shut-off valve 84 is arranged at the branch portion BP1 located on the start end side (most outdoor unit 10 side) of each group AD. Thereby, when refrigerant leakage occurs in any of the groups A to D, the amount of the leakage refrigerant is suppressed by controlling the shut-off valve 84 to be closed in the branch portion BP1 corresponding to the group in which the refrigerant leakage has occurred. It has come to be. That is, between the outdoor unit 10 and each indoor unit 40, the refrigerant flow path (connection circuit RC3) branches according to the number of indoor units 40 and other devices. In the air conditioning system 200, before the refrigerant flow path branches ( The shut-off valve 84 can be arranged on the branch portion BP on the outdoor unit 10 side), and when shutting off the flow of the refrigerant to the plurality of indoor units 40, the one shut-off valve 84 is connected to the plurality of indoor units. 40 can be shared. As a result, even if the shut-off valve 84 is not provided for each indoor unit 40, the refrigerant flow from the outdoor unit 10 side to the plurality of indoor units 40 can be shut off when the refrigerant leaks. For this reason, it is not necessary to arrange | position the shut-off valve 84 for every indoor unit 40 regarding a refrigerant | coolant leakage countermeasure, and it is suppressed that the number of the shut-off valves 84 increases. Such an effect can be expected particularly when the number of indoor units 40 is large as in the air conditioning system 200. Therefore, in the air conditioning system 200, a decrease in workability is particularly suppressed in connection with improving the safety against refrigerant leakage.

  Further, in the air conditioning system 200, since the number of indoor units 40 is large, if the shutoff valve 84 and the branch pipe are joined on site at the time of construction, the number of man-hours increases remarkably, so that the branch pipe unit 50 including the shutoff valve 84 is obtained. By being constructed on site, the working time and labor required for construction are particularly reduced.

  Further, in the air conditioning system 200, since the shut-off valve 84 is arranged for each group, when refrigerant leakage occurs, only the group in which refrigerant leakage has occurred is shut off, and the group in which refrigerant leakage has not occurred. Can continue driving.

  In the air conditioning system 200, shutoff valves 84 are arranged in the branch portion BP2 closest to the outdoor unit 10, the branch portion BP3 between the branch portion BP2 and the branch portion BP1, and the branch portions BP4-6 in each group. Not. That is, in the air conditioning system 200, the branch portion BP2 and the branch portion BP3 are configured by the branch pipe unit that does not have the shut-off valve 84.

  In the refrigerant circuit RC, the position (branch portion BP) where the shutoff valve 84 is arranged can be changed as appropriate. Specifically, the shut-off valve 84 is based on a refrigerant leakage amount assumed when refrigerant leakage occurs, and a part that needs to be shut off to ensure safety (for example, the branch part BP1- shown in FIG. 7). 6). For example, regarding the position (branch portion BP) where the shut-off valve 84 is disposed, the total number of indoor units 40, the total capacity, or the like that need to be shut off by the shut-off valve 84 to ensure safety when refrigerant leaks. It may be determined based on the total capacity of the end side connecting pipe. Alternatively, the shut-off valve 84 may be arranged for each device including the refrigerant filling amount corresponding to these.

That is, the shutoff valve 84 may be connected to any one of the following (a), (b), and (c) / all outdoor unit side connection pipes 81 (outdoor pipes).
(A): Outdoor unit side connection pipe 81 arranged between a plurality of indoor units 40 having a total capacity equal to or less than the first threshold value ΔTh1 and the outdoor unit 10.
(B): Outdoor unit side connection pipe 81 arranged between the plurality of indoor units 40 whose total number is equal to or smaller than the second threshold value ΔTh2 and the outdoor unit 10.
(C): Outdoor unit side connecting pipe 81 having a total capacity of communicating pipes on the other end side that is not more than the third threshold value ΔTh3

  In this case, the first threshold value ΔTh1, the second threshold value ΔTh2, and / or the third threshold value ΔTh3 is the size of any target space (for example, the narrowest target space) where the indoor unit 40 is installed and air conditioning is performed. Based on the above, it may be set in consideration of the possibility that the concentration of the leaked refrigerant becomes a dangerous value (combustion lower limit concentration or oxygen deficiency limit concentration) in the target space when the refrigerant leak occurs.

For example, the first threshold value ΔTh1, the second threshold value ΔTh2, and / or the third threshold value ΔTh3 are the refrigerant amount m (kg), the refrigerant combustion lower limit concentration G (kg / m ³ ), and the floor space A (m ² ) of the target space. ), The leakage height hr (m) may be set such that the shut-off valve 84 is arranged in a range where the following condition 1 is satisfied. Here, the refrigerant amount m is a refrigerant amount that can be charged into a device that is shut off from the outdoor unit 10 by the shut-off valve 84 in order to ensure the safety in the target space when the refrigerant leaks. The leakage height hr is a height position of a portion where the leakage refrigerant is assumed to flow out in the target space.
m ≤ G / 4 · A · hr (Condition 1)

  By determining the arrangement position of the shutoff valve 84 in such a manner, the safety (for example, the lower limit concentration of combustion and oxygen deficiency) when refrigerant leakage occurs according to the scale and environment of the facility where the air conditioning system is installed. The shut-off valve 84 can be accurately arranged at a portion where it is necessary to shut off the refrigerant in view of the limit concentration and the like. Therefore, ensuring safety against refrigerant leakage is further promoted while suppressing an increase in the number of shut-off valves 84.

(7-10) Modification 10
In the embodiment described above, the main body unit 51 of the branch pipe unit 50 is configured in a manner as shown in FIG. 2, but is not necessarily limited to such a manner and can be appropriately changed. That is, as for each part included in the main unit 51, as long as there is no contradiction in realizing the effect of the idea according to the present disclosure, the configuration, such as the shape, size, position, etc., according to the installation environment and design specifications These changes can be made and may be omitted as appropriate.

  For example, the main unit 51 may be configured as a main unit 51a shown in FIG. Hereinafter, the main unit 51a will be described with respect to portions different from the main unit 51.

  FIG. 8 is a schematic configuration diagram of the main unit 51a. The main unit 51 a has a shut-off valve 84 a instead of the shut-off valve 84. The cutoff valve 84a is different from the cutoff valve 84a in the following points.

  The shut-off valve 84a includes a second pipe connection portion 842a instead of the second pipe connection portion 842. The second pipe connection portion 842a is a tubular portion extending from the side portion of the valve main body portion 840 along a predetermined extending direction (x direction in FIG. 6). In the present embodiment, the shut-off valve 84a is substantially T-shaped and forms a substantially I-shaped refrigerant flow path 840a ′ therein. In this regard, in the shutoff valve 84a, the second pipe connection portion 842a extends in the opposite direction to the first pipe connection portion 841. That is, the extending direction (longitudinal direction) of the second pipe connecting portion 842a and the extending direction (longitudinal direction) of the first pipe connecting portion 841 are the same direction (x direction), but the extending directions of both are opposite. The extending direction of the first pipe connecting portion 841 is a direction that intersects the extending direction of the valve body N1.

  The second pipe connection part 842a communicates with the end of the refrigerant flow path 840a ′ in the valve main body part 840. One end of the second pipe connection portion 842a is joined to the side portion of the valve body portion 840. The other end of the second pipe connection part 842a is joined to the end part of the outdoor unit side connection pipe 81 (the end part on the one end side connection pipe side). More specifically, in the second pipe connection portion 842a, in the installed state, the indoor unit side connection pipes 82 are arranged along the horizontal direction, and the longitudinal direction of the indoor unit side connection pipes 82 extends along the horizontal direction. It is connected to the outdoor unit side connecting pipe 81 in a posture that enables the above.

  Such a main unit 51a may be arranged in a manner as shown in FIG. 9, for example. FIG. 9 is a schematic view showing an example of an installation mode of the branch pipe unit 50 ″ having the main body unit 51a. Hereinafter, in FIG. 9, unlike the installation mode of FIG. 3, the first pipe connection portion 841 of the shut-off valve 84 a is installed so as to extend in the left-right direction (x direction), not in the front-rear direction (z direction). . In this connection, in the ceiling space SP, the main extending direction of the other end side connecting pipe (here, the horizontal direction, that is, the horizontal direction) and the main extending direction of the one end side connecting pipe (here, the left and right direction, that is, the horizontal direction). Are substantially the same. That is, in the ceiling space SP having a small vertical length, the main body unit 51a includes the main extending direction of the other end side connecting pipe (here, the horizontal direction, that is, the horizontal direction) and the main extending direction of the one end side connecting pipe ( Here, they are arranged in such a posture that the left and right direction, that is, the horizontal direction) is substantially the same.

  The branch pipe unit 50 ″ having such a main body unit 51a can also achieve the same operational effects as the above embodiment.

(7-11) Modification 11
For example, the main unit 51 may be configured as a main unit 51b shown in FIG. Hereinafter, the main unit 51b will be described with respect to parts different from the main unit 51.

  FIG. 10 is a schematic configuration diagram of the main unit 51b. The main unit 51 b has a branch pipe 83 a instead of the branch pipe 83. The main unit 51b has three indoor unit side connecting pipes 82.

  The branch pipe 83a is different from the branch pipe 83 in the following points. The branch pipe 83a has a branch pipe main body 830a instead of the branch pipe main body 830. The branch pipe main body 830a is a substantially I-shaped header pipe. The 1st insertion part 831 is extended along the extending | stretching direction (x direction of FIG. 9) of the outdoor unit side connection pipe 81 from the part between the both ends of the branch pipe main-body part 830a. Each second insertion portion 832 is spaced apart from the other second insertion portion 832 in the z direction at a portion opposite to the arrangement position of the outdoor unit side connection pipe 81 between both ends of the branch pipe main body portion 830a. Are arranged in line. Each second insertion portion 832 extends in the opposite direction along the extending direction of the first insertion portion 831, and is disposed substantially parallel to the other second insertion portion 832.

  Even when the branch pipe unit 50 includes such a main body unit 51b, the same effect as that of the above-described embodiment can be realized. Moreover, in the main body unit 51b, since the distance between each 2nd insertion part 832 can be made smaller than the main body unit 51, even if it is a case where the number of the 2nd insertion parts 832 increases, a main body unit. 51b can be configured compactly, and in connection with this, improvement in workability can be expected.

(7-12) Modification 12
In the main unit 51, the outdoor unit side connecting pipe 81 may be omitted as appropriate. In this case, the main unit 51 may be configured as a main unit 51c shown in FIG. 11, for example. Hereinafter, the main unit 51c will be described with respect to parts different from the main unit 51.

  FIG. 11 is a schematic configuration diagram of the main unit 51c. In the main unit 51c, the outdoor unit side connecting pipe 81 is omitted. For this reason, the second pipe connection portion 842 of the shut-off valve 84 is joined (connected) to the first insertion portion 831 of the branch pipe 83.

  Even when the branch pipe unit 50 includes such a main body unit 51c, the same effects as those of the above-described embodiment can be realized.

(7-13) Modification 13
In the main unit 51, any or all of the plurality of indoor unit side connecting pipes 82 may be omitted as appropriate. In this case, the main unit 51 may be configured as a main unit 51d shown in FIG. 12, for example. Hereinafter, the main unit 51d will be described with respect to parts different from the main unit 51.

  FIG. 12 is a schematic configuration diagram of the main unit 51d. In the main unit 51d, each indoor unit side connecting pipe 82 is omitted. For this reason, in the main body unit 51d, the other end side connecting pipes (L2, L3, G2, G3) are joined to the second insertion portion 832 of the branch pipe 83.

  Even when the branch pipe unit 50 includes the main body unit 51d, the same effects as those of the above-described embodiment can be realized.

(7-14) Modification 14
Further, in the main unit 51, the outdoor unit side connecting pipe 81 may be joined to the first pipe connecting portion 841 of the shutoff valve 84. In such a case, the main unit 51 may be configured, for example, as a main unit 51e shown in FIG. Hereinafter, the main unit 51e will be described with respect to parts different from the main unit 51.

  FIG. 13 is a schematic configuration diagram of the main unit 51e. The main unit 51e further includes an outdoor unit side connecting pipe 81, and the outdoor unit side connecting pipe 81 is joined (connected) to one end of the first pipe connecting portion 841 of the shutoff valve 84. . And the one end side connection piping (L1 / G1) is joined to the other end of the outdoor unit side connection pipe 81.

  Even when the branch pipe unit 50 includes the main body unit 51e, the same effects as those of the above-described embodiment can be realized. When the outdoor unit side connecting pipe 81 is joined to the first pipe connecting portion 841 of the shut-off valve 84 as in the main unit 51e, one outdoor unit side is used as in the main unit 51c according to “Modification 3”. The connection pipe 81 may be omitted, and the second pipe connection part 842 of the cutoff valve 84 may be joined (connected) to the first insertion part 831 of the branch pipe 83.

(7-15) Modification 15
In the main unit 51, the valve main body 840 is configured such that the extending direction of the valve body N1 is the z direction, but the extending direction of the valve body N1 is not necessarily limited to the z direction. For example, the main unit 51 may be configured as, for example, a main unit 51f illustrated in FIG. Hereinafter, the main unit 51f will be described with respect to portions different from the main unit 51.

  FIG. 14 is a schematic configuration diagram of the main unit 51f. In the main unit 51f, the valve main body 840 ′ is configured such that the extending direction of the valve body N1 is the x direction. Even when the branch pipe unit 50 includes the main body unit 51f, the same effects as those of the above-described embodiment can be realized.

(7-16) Modification 16
Further, in the main unit 51, the shutoff valve 84 is located between the outdoor unit side connecting pipe 81 and the one end side connecting pipe and is connected to the outdoor unit side connecting pipe 81. However, the arrangement of the shut-off valve 84 is not necessarily limited to this, and the shut-off valve 84 is connected to the indoor unit side connecting pipe 82 as long as no contradiction arises in realizing the effect of the idea according to the present disclosure. May be.

  For example, the main unit 51 may be configured as a main unit 51g shown in FIG. 15, for example. Hereinafter, the main unit 51g will be described with respect to portions different from the main unit 51.

  FIG. 15 is a schematic configuration diagram of the main unit 51g. The main unit 51g has a plurality of shut-off valves 84a similar to the main unit 51a (the same number as the indoor unit side connecting pipes 82) instead of the shut-off valve 84. As will be described later, the shut-off valve 84a arranged in the main unit 51g has a smaller size than that arranged in the main unit 51a.

  In the main body unit 51g, each shut-off valve 84a is associated with one of the indoor unit side connecting pipes 82 on a one-to-one basis. In relation to this, in the main body unit 51g, each shut-off valve 84a is associated one-to-one or one-to-many with one of the other end side connecting pipes (indoor unit 40).

  In the main body unit 51g, one end of the first pipe connecting portion 841 of the shut-off valve 84a is joined to the side portion of the valve main body portion 840, and the other end corresponds to the end portion of the indoor unit side connecting pipe 82 (the other end side connecting pipe). Side end).

  In the main body unit 51g, one end of the second pipe connecting portion 842a of the shut-off valve 84a is joined to the side portion of the valve main body portion 840, and the other end is joined to the corresponding other end side connecting pipe. More specifically, in the second pipe connection portion 842a, in the installed state, the indoor unit side connection pipes 82 are arranged along the horizontal direction, and the longitudinal direction of the indoor unit side connection pipes 82 extends along the horizontal direction. It is connected to the other end side connecting pipe in a posture that enables the

  Such a main unit 51g may be arranged in the same manner as shown in FIG. 9, for example. That is, the main body unit 51g is installed such that the first pipe connection portion 841 of the shut-off valve 84a extends in the left-right direction (x direction) instead of the front-rear direction (z direction). , The main extending direction of the other end side connecting pipe (here, the horizontal direction, ie, the horizontal direction) and the main extending direction of the one end side connecting pipe (here, the left and right direction, ie, the horizontal direction) are substantially the same. May be. That is, in the ceiling space SP having a narrow vertical length, the main unit 51g has a main extending direction of the other end side connecting pipe (here, the horizontal direction, that is, a horizontal direction) and a main extending direction of the one end side connecting pipe ( Here, the left and right directions (ie, the horizontal direction) may be arranged so as to be substantially the same.

  In the shut-off valve 84a disposed in the main unit 51g, the first pipe connecting portion 841 is connected to the indoor unit side connecting pipe 82 having an inner diameter smaller than that of the outdoor unit side connecting pipe 81, and the second pipe connecting portion 842 is one end. It is connected to the other end side connecting pipe whose inner diameter is smaller than that of the side connecting pipe. In this connection, the shut-off valve 84a arranged in the main unit 51g has a smaller size than that arranged in the main unit 51a.

  Even when the branch pipe unit 50 (50 ') has such a main body unit 51g, the same effects as those of the above-described embodiment can be realized.

  That is, the main unit 51g connects the one end side connecting pipe and a plurality of other end side connecting pipes, and communicates with the outdoor unit side connecting pipe 81 communicating with the one end side connecting pipe and the corresponding other end side connecting pipe. A plurality of indoor unit side connection pipes 82, a branch pipe 83 communicating the outdoor unit side connection pipes 81 and the plurality of indoor unit side connection pipes 82, and a corresponding indoor unit side connection pipe 82 to be closed. And a plurality of shut-off valves 84a that prevent the flow of the refrigerant. That is, between the outdoor unit 10 and each indoor unit 40, the refrigerant flow path branches according to the number of indoor units 40 and other devices. Even when the branch pipe unit 50 includes the main body unit 51g, the refrigerant flow path The shut-off valve 84a can be disposed before the branching (more specifically, on the outdoor unit 10 side of the branch pipe 83 located on the indoor unit 40 side of the branch pipe 83). Thereby, in order to interrupt | block the flow of the refrigerant | coolant to the several indoor unit 40, it becomes possible to share the one cutoff valve 84a with respect to the several indoor unit 40. FIG. As a result, even if the shut-off valve 84a is not arranged for each indoor unit 40, the refrigerant flow from the outdoor unit 10 side to the plurality of indoor units 40 can be shut off when the refrigerant leaks. For this reason, it is not necessary to arrange | position the shut-off valve 84a for every indoor unit 40 regarding a refrigerant | coolant leakage countermeasure, and it is suppressed that the number of the shut-off valves 84a installed on refrigerant | coolant communication piping increases.

  The main unit 51g can be installed on the refrigerant communication pipe with the outdoor unit side connecting pipe 81, the plurality of indoor unit side connecting pipes 82, the branch pipe 83, and the plurality of shut-off valves 84a assembled in advance. Is possible. In this respect, if many shut-off valves 84a and branch pipes are joined on site at the time of construction, the number of man-hours increases. However, when the branch pipe unit 50 has the main body unit 51g, the work time and labor required for construction are reduced. It has become so.

  In the main unit 51g, a plurality of shut-off valves 84a are arranged. When the shut-off valve 84a is connected to the indoor unit side connecting pipe 82, the main unit 51g shuts off the outdoor unit side connecting pipe 81. It is possible to use a shut-off valve 84a having a smaller size than when the valve 84a is connected. In relation to this, in the main body unit 51g, despite the arrangement of the plurality of shut-off valves 84a, the downsizing is promoted, and the deterioration of workability is suppressed even in a narrow space.

  Therefore, in connection with improving the safety | security with respect to refrigerant | coolant leakage in an air conditioning system, the fall of workability is suppressed.

  In the main unit 51g, the outdoor unit side connecting pipe 81 is not necessarily required and can be omitted as appropriate. Further, in the main unit 51g, the one shut-off valve 84a (more specifically, the shut-off valve 84a that is one-to-one associated with the other end side connection pipe (indoor unit 40) is not necessarily required. May be omitted as appropriate.

  Of course, the main unit 51g may have a shut-off valve 84 instead of the shut-off valve 84a. In such a case, the main unit 51g may be configured like a main unit 51g ′ shown in FIG. The main unit 51g ′ has a branch pipe 83 ′ instead of the branch pipe 83. The branch pipe 83 ′ is not substantially U-shaped like the branch pipe 83, but is substantially T-shaped. In this regard, in the branch pipe 83 ′, the indoor unit side connection pipe 82 extends along the z direction (horizontal direction). In each shut-off valve 84, the first pipe connection part 841 extending along the z direction is connected to the corresponding indoor unit side connection pipe 82, and the second pipe connection part 842 extending along the x direction is connected to the other end side. Connected to piping. Further, since the main body unit 51g ′ uses the substantially T-shaped branch pipe 83 ′, the x-direction of the main body unit 51g ′ is larger than the case where the substantially U-shaped branch pipe 83 is used like the main body unit 51g. It is possible to reduce the size of the device.

(7-17) Modification 17
Further, the main unit 51 may be configured as a main unit 51h shown in FIG. 17, for example. Hereinafter, the main unit 51h will be described with respect to parts different from the main unit 51g.

  FIG. 17 is a schematic configuration diagram of the main unit 51h. In the main body unit 51h, one end of the first pipe connection portion 841 of the shutoff valve 84a is joined to the side portion of the valve main body portion 840, and the other end is joined to the branch pipe 83. In the main unit 51g, one end of the second pipe connection portion 842a of the shut-off valve 84a is joined to the side portion of the valve main body portion 840, and the other end of the second pipe connection portion 842a is the end of the indoor unit side connection pipe 82. It joins to the part (end part by the side of one end side connection piping).

  Even when the branch pipe unit 50 (50 ′) includes such a main body unit 51h, the same operational effects as when the branch pipe unit 50 includes the main body unit 51g can be realized.

(7-18) Modification 18
Further, when the branch pipe unit 50 (50 ′) has the main unit 51g (51g ′) or the main unit 51h, for example, an air conditioning system 300 shown in FIG. It may be applied to an air conditioning system that is connected to the unit 10 and in which each indoor unit 40 is arranged in series or in parallel with the other indoor units 40. FIG. 18 is a schematic configuration diagram of an air conditioning system 300 to which the main body unit 51g (51g ′) or the branch pipe unit 50 having the main body unit 51h is applied. In FIG. 18, the liquid side communication pipe La and the gas side communication pipe Ga are shown together to simplify the illustration.

  In the air conditioning system 300, like the air conditioning system 200, each connecting pipe (La, Ga) extending between the outdoor unit 10 and each indoor unit 40 branches into a plurality (here, four in large), and is arranged at the branch destination. A plurality (four) of groups (AD) are configured with respect to the indoor unit 40 to be performed. In the air conditioning system 300, each group A-D includes a plurality of indoor units 40.

  In FIG. 18, the branch portion BP1 located on the start end side (most outdoor unit 10 side) of each group AD is configured by a branch pipe unit 50 having a main body unit 51g or a main body unit 51h. In FIG. 18, one shut-off valve 84a is associated with the indoor unit 40 located closest to the outdoor unit 10 in the group on a one-to-one basis, and is controlled to the closed state to the corresponding indoor unit 40. Block the flow of refrigerant. The other shut-off valve 84a is associated with the other indoor units 40 included in the group in a one-to-many manner, and is prevented from flowing into the corresponding indoor unit 40 by being controlled to be closed. . That is, in the air conditioning system 300 as well, one shutoff valve 84 a is shared by the plurality of indoor units 40 in order to block the flow of the refrigerant to the plurality of indoor units 40.

  When the branch pipe unit 50 is configured and arranged in the manner as shown in FIG. 18, when refrigerant leakage occurs in any of the groups AD, each of the branch portions BP1 corresponding to the group in which the refrigerant leakage occurs By controlling the shut-off valve 84a to the closed state, the amount of refrigerant leaked is suppressed. As a result, even if the shut-off valve 84a is not arranged for each indoor unit 40, the refrigerant flow from the outdoor unit 10 side to the plurality of indoor units 40 can be shut off when the refrigerant leaks. For this reason, it is not necessary to arrange | position the shut-off valve 84a for every indoor unit 40 regarding a refrigerant | coolant leakage countermeasure, and it is suppressed that the number of the shut-off valves 84a increases. Such an effect can be expected particularly when the number of indoor units 40 is large as in the air conditioning system 300. Therefore, in the air conditioning system 300, a decrease in workability is particularly suppressed in connection with improving the safety against refrigerant leakage.

  Further, in the air conditioning system 300, since the number of indoor units 40 is large, if the control valve and the branch pipe are joined in the field at the time of construction, the man-hour is remarkably increased. Labor is particularly reduced.

  Further, in the air conditioning system 300, since the branch pipe unit 50 is arranged for each group, when refrigerant leakage occurs, only the group in which refrigerant leakage has occurred is blocked and the group in which refrigerant leakage does not occur Can continue driving.

  In the air conditioning system 300, the shutoff valve 84a is not arranged in the branch portion BP2 closest to the outdoor unit 10, the branch portion BP3 between the branch portion BP2 and the branch portion BP1, and the branch portions BP4-6 in each group. . That is, in the air conditioning system 300, the branch portion BP2 and the branch portion BP3 are configured by the branch pipe unit 50 that does not have the shut-off valve 84a.

  In the refrigerant circuit RC, the position (branch portion BP) where the shut-off valve 84a is disposed can be changed as appropriate. Specifically, the shut-off valve 84a is a portion that needs to be shut off for ensuring safety based on the amount of refrigerant leakage that is assumed when refrigerant leakage occurs (for example, the branch portion BP1- shown in FIG. 18). 6). For example, regarding the position (branch portion BP) where the shut-off valve 84a is disposed, the total number of indoor units 40, the total capacity, or the like that need to be shut off by the shut-off valve 84a to ensure safety when refrigerant leaks. It may be determined based on the total capacity of the end side connecting pipe. Or the cutoff valve 84a may be arrange | positioned for every apparatus in which the refrigerant | coolant filling amount equivalent to these is contained.

In other words, the shutoff valve 84a may be connected to any one or all of the following (d), (e), and (f) indoor unit side connection pipes 82 (indoor side pipes).
(D): Indoor unit side connecting pipe 82 arranged between the plurality of indoor units 40 whose total capacity is equal to or less than the fourth threshold value ΔTh4 and the outdoor unit 10.
(E): Indoor unit side connecting pipe 82 arranged between the plurality of indoor units 40 whose total number is equal to or smaller than the fifth threshold value ΔTh5 and the outdoor unit 10.
(F): The indoor unit side connecting pipe 82 in which the total capacity of the communicating pipes on the other end side is 6th threshold value ΔTh6 or less.

  In this case, the fourth threshold value ΔTh4, the fifth threshold value ΔTh5, and / or the sixth threshold value ΔTh6 is the size of any target space (for example, the narrowest target space) where the indoor unit 40 is installed and air conditioning is performed. Based on the above, it may be set in consideration of the possibility that the concentration of the leaked refrigerant becomes a dangerous value (combustion lower limit concentration or oxygen deficiency limit concentration) in the target space when the refrigerant leak occurs.

  For example, the fourth threshold value ΔTh4, the fifth threshold value ΔTh5, and / or the sixth threshold value ΔTh6 is set so that the shutoff valve 84a is arranged in a range in which the above-described condition 1 (see Modification 9) is satisfied. May be.

  By determining the arrangement position of the shut-off valve 84a in such a manner, the safety (for example, the lower limit concentration of combustion and oxygen deficiency) when refrigerant leakage occurs according to the scale and environment of the facility where the air conditioning system is installed. The shut-off valve 84a can be accurately arranged at a portion where it is necessary to shut off the refrigerant in view of the limit concentration and the like. Therefore, ensuring safety against refrigerant leakage is further promoted while suppressing an increase in the number of shutoff valves 84a.

  In FIG. 18, one shutoff valve 84a is associated with the indoor unit 40 located closest to the outdoor unit 10 in the group on a one-to-one basis, but the other shutoff valve 84a is also associated with the other shutoff valve 84a. Similarly to 84a, the indoor units 40 may be associated one-to-many. Further, the shut-off valve 84a is not necessarily required and may be omitted as appropriate.

(7-19) Modification 19
Although not specifically described in the above embodiment, the main body unit 51 and a part of the one end side connecting pipe and / or the other end side connecting pipe may be brought into the field in an integrated state and installed. Good. That is, the main unit 51 and a part of the one end side connecting pipe and / or the other end side connecting pipe may be connected (joined) in advance at a factory or the like.

  In particular, in FIG. 3, the one end side connecting pipe is curved in the vicinity of the connection portion with the main unit 51. As described above, when the refrigerant communication pipe includes a curved portion, the labor required for the construction is particularly reduced by performing the construction in a state in which the curved portion is configured integrally with the main body unit 51 in advance. That is, the workability is improved.

  In such a case, with respect to a part of the refrigerant communication pipe integrated with the main unit 51, if the viewpoint is changed, the constituent elements of the main unit 51 (for example, the outdoor unit side connection pipe 81 and / or the indoor unit side connection pipe 82). ).

(7-20) Modification 20
Although not specifically described in the above embodiment, the main body unit 51 and the heat insulating material 95 may be carried into the site and installed in an integrated state. That is, the main body unit 51 may be covered with the heat insulating material 95 in advance at a factory or the like. Thereby, the labor required for construction is reduced and the workability is improved. In such a case, the heat insulating material 95 integrated with the main body unit 51 can be interpreted as a component of the main body unit 51 from a different viewpoint.

  In addition, about the part connected with other piping in a construction site, after connecting with other piping, what is necessary is just to coat | cover with the heat insulating material 95 anew.

(7-21) Modification 21
In the above embodiment, in the electrical component unit 52, the electrical component 521 is mounted on the substrate 522. However, the electrical component 521 is not necessarily mounted on the substrate 522. For example, the electrical component 521 may be independently arranged in the unit casing 523.

(7-22) Modification 22
In the said embodiment, the electric wire 53 was comprised by the dimension of the longitudinal direction to 1.2 m. However, the electric wire 53 does not necessarily need to be configured in such a manner, and the longitudinal dimension of the electric wire 53 can be changed as appropriate. For example, the electric wire 53 may have a longitudinal dimension of 1 m or 2 m.

  In addition, in the construction site, it is possible to install the main unit 51 and the electrical component unit 52 apart from each other by 1 m or more, and according to the viewpoint of improving the degree of freedom of construction, the longitudinal dimension is 1.0 m or more. Thus, the electric wire 53 is preferably configured. However, the configuration aspect of the electric wire 53 is not necessarily limited to this, and the dimension in the longitudinal direction may be less than 1 m.

(7-23) Modification 23
In the above embodiment, the electrical component unit 52 is provided independently of the main body unit 51 so as to be freely moved with respect to the main body unit 51. In this regard, according to the viewpoint that the electrical component unit 52 is configured independently of the main body unit 51, the electrical component unit 52 can be moved at the site to increase the degree of freedom of construction and to make each unit compact. The electrical component unit 52 is preferably configured in such a manner. However, the present invention is not necessarily limited thereto, and the electrical component unit 52 may be configured integrally with the main body unit 51.

(7-24) Modification 24
In the above embodiment, the case where the outdoor unit side connecting pipe 81 and the branch pipe 83 are joined and the indoor unit side connecting pipe 82 and the branch pipe 83 are joined has been described with respect to the main body unit 51. In this regard, any / all of the outdoor unit side connecting pipe 81 and each indoor unit side connecting pipe 82 may be integrally formed with the branch pipe 83.

(7-25) Modification 25
In the above embodiment, the case where the outdoor unit side connecting pipe 81, the indoor unit side connecting pipe 82, and the branch pipe 83 are made of the same copper as the one end side connecting pipe has been described with respect to the main body unit 51. However, the material of the outdoor unit side connecting pipe 81, the indoor unit side connecting pipe 82, the branch pipe 83, and the other parts of the main unit 51 is not particularly limited, and can be appropriately selected according to the design specifications and installation environment. That's fine.

(7-26) Modification 26
In the above embodiment, the case where the main unit 51 has one outdoor unit side connection pipe 81 and two indoor unit side connection pipes 82 has been described. However, the number of outdoor unit side connection pipes 81 and the number of indoor unit side connection pipes 82 in the main unit 51 are not necessarily limited to this, and can be changed as appropriate. For example, the main unit 51 may have two or more outdoor unit side connecting pipes 81. The main unit 51 may have three or more indoor unit side connecting pipes 82. That is, the number of branches in the main unit 51 (branch portion BP) is not limited to two and may be three or more.

(7-27) Modification 27
In the above embodiment, the case where the main unit 51 is installed without being housed in a casing or the like has been described. In this respect, from the viewpoint of promoting compactness, the main unit 51 is preferably installed in such a manner. However, the installation mode of the main unit 51 is not necessarily limited to this, and may be appropriately selected according to design specifications and installation environment. For example, the main unit 51 may be installed in a state accommodated in a casing.

(7-28) Modification 28
In the above embodiment, the case where the electrical component unit 52 is suspended from the ceiling space SP by mounting the fixture 90 fixed to the ceiling surface C2 has been described. However, the installation mode of the electrical component unit 52 is not necessarily limited to this, and can be appropriately changed according to design specifications and installation environment. For example, the electrical component unit 52 may be installed by being placed on the ceiling bottom surface C1 or a beam, or may be installed by being fixed to a pillar or a wall.

(7-29) Modification 29
In the above embodiment, in the branch pipe unit 50, the outdoor unit side connection pipe 81 (outdoor pipe), the plurality of indoor unit side connection pipes 82 (indoor side pipe group), the branch pipe 83 (branch part), and the cutoff The valve 84 is integrally formed. However, the branch pipe unit 50 does not necessarily need to be configured in such a manner, and any element may be configured as a separate body and may be configured to be connected to other elements at the site.

  For example, the plurality of indoor unit side connecting pipes 82 (indoor side piping group) may be configured not to be included in the branch pipe unit 50 but to be independently carried into the construction site and connected to other pipes.

  Further, for example, the shut-off valve 84 is not necessarily configured integrally with other elements included in the branch pipe unit 50. That is, the shut-off valve 84 may be configured to be independently carried into the construction site and connected to other piping. Even in such a case, the effects described in (6-1) above can be realized.

(7-30) Modification 30
Any of the valves arranged in the refrigerant circuit RC according to the above embodiment has a liquid seal suppression structure that suppresses the formation of a liquid seal circuit in the refrigerant circuit RC when the shutoff valve 84 is closed. You may do it. For example, any / all of the indoor expansion valve 41, the shut-off valve 84, and the outdoor first electric valve 16 may have a liquid seal suppression structure. The liquid seal suppression structure is not particularly limited as long as it is a structure that suppresses the formation of the liquid seal circuit. For example, as the liquid seal suppression structure, a minute flow path that allows a small amount of refrigerant to pass in the closed state may be formed in the valve. In such a case, a minute flow path may be formed by forming a notch or the like in the valve seat or the valve body. In addition, for example, as a liquid seal suppression structure, a valve may be configured to allow a small amount of refrigerant to pass when a pressure higher than a predetermined value is applied even in a closed state.

  Further, instead of arranging / disposing a valve having a liquid seal suppression structure, a liquid seal suppression mechanism may be arranged in the refrigerant circuit RC. The liquid seal suppression mechanism is a mechanism that suppresses the formation of a liquid seal circuit in the refrigerant circuit when the control valve is closed. The liquid seal suppression mechanism is not particularly limited as long as it is a mechanism that suppresses the formation of the liquid seal circuit. For example, in the refrigerant circuit RC, a refrigerant pipe that forms a bypass circuit that bypasses the refrigerant from the flow path on one end side to the flow path on the other end side of the shutoff valve 84 may be arranged as a liquid seal suppression mechanism. In such a case, the liquid seal suppression mechanism may include a check valve that is arranged on the bypass circuit and allows the refrigerant to flow only in one direction, or an on-off valve that switches between opening and closing of the bypass circuit.

  This suppresses the formation of a liquid ring circuit in the refrigerant circuit RC when the refrigerant leaks and the shut-off valve 84 is closed. That is, in the above embodiment, the indoor expansion valve 41 is controlled to be closed in the first refrigerant leakage control, and the shutoff valve 84 is controlled to be closed in the third refrigerant leakage control. For this reason, a liquid ring circuit can be formed in the refrigerant circuit RC. For example, a liquid ring circuit can be formed between the shutoff valve 84 and the indoor expansion valve 41 of the branch pipe unit 50 (50a or 50b). Further, for example, a liquid ring circuit can be formed between the shutoff valve 84 of the branch pipe unit 50 (50a) and the outdoor first electric valve 16.

  However, for example, any / all of the indoor expansion valve 41, the shut-off valve 84, and the outdoor first electric valve 16 have a liquid seal suppression structure, so that the formation of such a liquid seal circuit is suppressed. . Further, for example, in the refrigerant circuit RC, a bypass circuit that bypasses the refrigerant from the flow path between the shut-off valve 84 and the indoor expansion valve 41 to the flow path closer to the outdoor unit 10 than the shut-off valve 84 is formed as a liquid seal suppression mechanism. By arranging the refrigerant piping to be performed, the formation of the liquid ring circuit is suppressed. Therefore, the occurrence of damage to the device due to the formation of the liquid ring circuit when the refrigerant leaks is suppressed. That is, a decrease in reliability is suppressed.

(8)
Although the embodiments have been described above, it will be understood that various changes in form and details can be made without departing from the spirit and scope described in the claims.

  The present disclosure can be used for an air conditioning system.

10: Outdoor unit
16: Outdoor first electric valves 40, 40a, 40b: Indoor unit 41: Indoor expansion valve (electric valve)
50, 50 ', 50'': Branch pipe unit 50a: First branch pipe unit 50b: Second branch pipe unit 51, 51a-h: Main unit 52: Electrical component unit 53: Electric wire unit 60: Refrigerant leakage sensor 65: Remote control 70: Controller 81: Outdoor unit side connection pipe (outdoor pipe)
82: Indoor unit side connection pipe (indoor side piping)
83, 83 ', 83a: Branch pipe (branch part)
84, 84a: shut-off valve (control valve)
90: fixture 95: heat insulating material 100, 100 ', 200, 300: air conditioning system 521: electrical component 522: substrate 523: unit casing 524: fixed portion 830: branch pipe main body 830a: branch pipe main body 831: first Insertion part 832: 2nd insertion part 840, 840 ': Valve main-body part 841: 1st piping connection part 842, 842a: 2nd piping connection part AD: Group BP, BP1-6: Branch part (1st portion)
BPa: Liquid side branch part (first part)
BPb: Gas side branch portion (first portion)
C1: Ceiling back bottom C2: Ceiling back top G1: First gas side connecting pipe G2: Second gas side connecting pipe G3: Third gas side connecting pipe Ga: Gas side connecting pipe (refrigerant connecting pipe)
L1: First liquid side connecting pipe L2: Second liquid side connecting pipe L3: Third liquid side connecting pipe La: Liquid side connecting pipe (refrigerant connecting pipe)
P1-P11: 1st piping P1- 11th piping P17-P18: 17th piping P17-18th piping RC: Refrigerant circuit RC1: Outdoor side circuit RC2: Indoor side circuit RC3: Communication circuit RC3a: Liquid side communication circuit RC3b: Gas side connection circuit SP: Ceiling space

Japanese Patent Laid-Open No. 5-118720

Claims (11)

An air conditioning system (100, 100 ', 200) that performs a refrigeration cycle in a refrigerant circuit (RC),
An outdoor unit (10);
A plurality of indoor units (40);
Refrigerant communication piping (Ga, La) connecting the outdoor unit and the indoor unit;
A control valve (84, 84a) disposed on the refrigerant communication pipe to block the flow of the refrigerant;
With
The refrigerant communication pipe is
A plurality of indoor pipes (82) communicating with the corresponding indoor unit;
On the outdoor unit side, outdoor pipes (81) communicating with the corresponding plurality of indoor pipes;
A branch section (83, 83a) for connecting an indoor pipe group (82) constituted by two or more indoor pipes and the outdoor pipe;
Including
The outdoor pipe is connected to both the refrigerant flowing from the outdoor unit side to the indoor unit side via the corresponding indoor pipe and the refrigerant flowing from the indoor unit to the outdoor unit via the corresponding indoor pipe. Forming a common refrigerant flow path,
The control valve is disposed on the outdoor pipe.
Air conditioning system (100, 100 ', 200). An air conditioning system (100, 100 ', 300) that performs a refrigeration cycle in a refrigerant circuit (RC),
An outdoor unit (10);
A plurality of indoor units (40);
Refrigerant communication piping (Ga, La) connecting the outdoor unit and the indoor unit;
A control valve (84, 84a) disposed on the refrigerant communication pipe to block the flow of the refrigerant;
With
The refrigerant communication pipe is
A plurality of indoor pipes (82) communicating with the corresponding indoor unit;
On the outdoor unit side, outdoor pipes (81) communicating with the corresponding plurality of indoor pipes;
A branch portion (83, 83 ′, 83a) connecting the indoor side pipe group (82) constituted by two or more indoor side pipes and the outdoor side pipe;
Including
The outdoor pipe is connected to both the refrigerant flowing from the outdoor unit side to the indoor unit side via the corresponding indoor pipe and the refrigerant flowing from the indoor unit to the outdoor unit via the corresponding indoor pipe. Forming a common refrigerant flow path,
The control valve is disposed on the corresponding indoor pipe.
Air conditioning system (100, 100 ', 300). The refrigerant communication pipe includes a plurality of first parts (BP) having one outdoor pipe, one branching section, and the indoor pipe group,
When the control valve is disposed on the outdoor-side piping, the control valve is disposed on the outdoor-side piping in a part of the first portion (BPb, BP1), and is disposed on the indoor-side piping. Is arranged on the indoor side piping in a part of the first part (BPb, BP1),
The air conditioning system (100 ', 200, 300) according to claim 1 or 2. The refrigerant communication pipe includes a gas side communication pipe (Ga) through which a low-pressure refrigerant flows, and a liquid side communication pipe (La) through which a high-pressure or intermediate-pressure refrigerant flows.
The control valve is arranged on the outdoor pipe included in the gas side communication pipe when arranged on the outdoor pipe, and the gas side communication when arranged on the indoor pipe. Arranged on the indoor pipe included in the pipe,
The air conditioning system (100, 100 ', 200, 300) according to any one of claims 1 to 3. The control valve is also arranged on the outdoor pipe included in the liquid side communication pipe when arranged on the outdoor pipe, and the liquid side when arranged on the indoor pipe. It is also arranged on the indoor side pipe included in the communication pipe.
The air conditioning system (100, 100 ', 200, 300) according to claim 4. The indoor unit includes an electric valve (41) that blocks the refrigerant flowing into the indoor unit by depressurizing the refrigerant according to the opening degree during the operation and closing when the refrigerant leaks.
The air conditioning system (100, 100 ', 200, 300) according to any one of claims 1 to 5. When the control valve is arranged on the outdoor pipe, it is arranged on any one of the following A, B, and C / all the outdoor pipes, and on the indoor pipe. Is arranged on any of the following D, E and F / all the indoor pipes,
A: The outdoor piping arranged between the plurality of indoor units whose total capacity is equal to or less than a first threshold, and the outdoor unit,
B: The outdoor piping arranged between the plurality of indoor units whose total number is equal to or less than a second threshold and the outdoor unit,
C: the outdoor pipe, the total capacity of the refrigerant communication pipes located on the indoor unit side being a third threshold value or less,
D: The indoor-side piping disposed between the plurality of indoor units having a total capacity equal to or less than a fourth threshold, and the outdoor unit,
E: the indoor-side piping arranged between the plurality of indoor units whose total number is equal to or less than a fifth threshold, and the outdoor unit,
F: The indoor side pipe whose total capacity of the refrigerant communication pipe located on the indoor unit side is equal to or less than a sixth threshold value,
The air conditioning system (200, 300) according to any one of claims 1 to 6. The first threshold value, the second threshold value, the third threshold value, the fourth threshold value, the fifth threshold value, and the sixth threshold value are the size of any target space in which the indoor unit is installed and air conditioning is performed. Set based on
The air conditioning system (200, 300) according to claim 7. The outdoor side pipe and / or the indoor side pipe are configured integrally with the branch portion and the control valve.
The air conditioning system (100, 100 ', 200, 300) according to any one of claims 1 to 8. The refrigerant communication pipe includes branch pipe units (50, 50 ′, 50 ″) that are pre-assembled and connected to other pipes (L1-L3, G1-G3) at a construction site,
The branch pipe unit includes the outdoor pipe and / or the indoor pipe, the branch section, and the control valve, which are integrally formed.
The air conditioning system (100, 100 ', 200, 300) according to claim 9. Any of the valves (84, 84a, 41, 16) arranged in the refrigerant circuit is a liquid seal that suppresses formation of a liquid seal circuit in the refrigerant circuit when the control valve is closed. Having a restraining structure and / or
The refrigerant circuit is provided with a liquid seal suppression mechanism that suppresses formation of a liquid seal circuit in the refrigerant circuit when the control valve is in a closed state.
The air conditioning system (100, 100 ', 200, 300) according to any one of claims 1 to 10.

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