JPWO2018092186A1 - Flow path switching valve and air conditioner using the same - Google Patents

Abstract

  The flow path switching valve is provided between the gas pipe in which the refrigerant flows in and out and the low pressure pipe in which the refrigerant flows out, and the first shut-off valve which permits or blocks the flow of the refrigerant, the high pressure where the gas pipe and the refrigerant flow A second shutoff valve provided between the gas piping and permitting or blocking the flow of the refrigerant, and at least a gas piping, a low pressure piping, and a first shutoff valve connected and connected to the gas piping, the low pressure piping and the And a drive circuit for driving the flow path switching circuit, the drive circuit driving the refrigerant flowing into the first shut off valve to the low pressure pipe The first shutoff valve is opened by connecting the flow passage communicating with the first shutoff valve in the flow passage switching circuit and the flow passage communicating with the low pressure pipe so as to draw in the first shutoff valve.

Description

  The present invention relates to a flow path switching valve applied to an air conditioner such as a multi-air conditioner for buildings, and an air conditioner using the same.

  2. Description of the Related Art Conventionally, a flow path switching valve is used which switches and supplies a refrigerant type to be supplied to an indoor unit mainly in a branch unit of a multi-air conditioner for buildings. Such a flow path switching valve includes an electromagnetic shutoff valve, and can connect the indoor unit side pipe, the high pressure gas pipe, and the low pressure pipe to switch the cooling flow path or the heating flow path (for example, patent Reference 1).

  The flow path switching valve described in Patent Document 1 includes an electromagnetic shut-off valve that shuts off the flow path from the indoor unit side to the low pressure pipe side, and an electromagnetic type that shuts off the flow path from the high pressure gas pipe side to the indoor unit side It is equipped with a shutoff valve. In addition, in order to reduce the residual pressure on the indoor unit side, a thin flow path communicating from the indoor unit side to the low pressure pipe side is provided in the flow path switching valve. The flow path switching valve further includes an electromagnetic shutoff valve that shuts off the flow path. That is, the flow path switching valve includes three flow paths and three electromagnetic shutoff valves.

Japanese Patent Laid-Open No. 5-322348

  By the way, since the above-mentioned channel switching valve has three electromagnetic shutoff valves, it is necessary to install the shutoff valves in front and back. Also, in view of accessibility when replacing the coil for driving the shutoff valve and the valve, the flow path switching valve can easily access the shutoff valve installed on both the front and rear, It is necessary to arrange structures such as piping and sheet metal. Therefore, the housing size of the branching unit becomes large, and downsizing becomes difficult. Thus, for example, when installing the branching unit on the ceiling of a building, if the height of the ceiling is low, it becomes difficult to install the branching unit, and the area of the sheet metal forming the outer shell becomes large, There is a problem that the cost is increased.

  In addition, although such an electromagnetic shutoff valve generally uses a solenoid valve coil driven at a voltage of about 200 V, there is a risk of ignition if an arc is generated in the solenoid valve coil. Therefore, it is necessary to form the outer shell structure of the branching unit using a material such as sheet metal having a low risk of combustion, and the drain pan or the surrounding sheath can not be changed to a cheap material but a foamable material such as expanded polystyrene. . As a result, condensation occurs due to the increase of the airtightness, and there is a problem that the generation of drain water due to the condensation can not be suppressed.

  This invention is made in view of the said subject, Comprising: The freedom degree of installation is improved, The flow-path switching valve which can improve workability | operativity, such as a maintenance, and the air conditioner using it are provided. The purpose is to

  The flow path switching valve according to the present invention is provided between a gas pipe in which the refrigerant flows in and out and a low pressure pipe in which the refrigerant flows out, and the first shutoff valve which permits or blocks the flow of the refrigerant; And a second shut-off valve provided between the fuel cell and the high-pressure gas pipe into which the refrigerant flows in, and which is connected to at least the gas pipe, the low-pressure pipe, and the first shut-off valve. A flow path switching circuit that switches connection of a flow path between the connected gas pipe, the low pressure pipe, and the first shutoff valve, and a drive circuit that drives the flow path switching circuit, the drive circuit Connects the flow passage communicating with the first shutoff valve in the flow passage switching circuit and the flow passage communicating with the low pressure piping so as to draw the refrigerant flowing into the first shutoff valve into the low pressure piping Causes the first shielding to It is intended to open the valve.

  As described above, according to the air conditioner of the present invention, by controlling the shutoff valve based on the operation of the flow path switching circuit, the degree of freedom of installation can be improved, and the workability such as maintenance can be improved. .

FIG. 2 is a schematic view showing an installation example of the air conditioner according to Embodiment 1. It is the schematic which shows an example of a circuit structure of the air conditioner shown in FIG. FIG. 2 is a schematic view showing an example of the configuration of a flow path switching valve according to Embodiment 1. It is the schematic which shows an example of the structure of the flow-path switching valve shown in FIG. It is the schematic which shows the other example of the structure of the flow-path switching valve shown in FIG. It is the schematic which shows the state of each flow path and cylinder in the flow-path switching valve of FIG. FIG. 8 is a schematic view showing an example of the configuration of a flow passage switching valve according to Embodiment 2. FIG. 13 is a schematic view showing an example of the configuration of a flow passage switching valve according to Embodiment 3. It is the schematic which shows an example of the structure of the flow-path switching valve shown in FIG. It is the schematic which shows the state of each flow path and cylinder in the flow-path switching valve of FIG.

Embodiment 1
Hereinafter, the air conditioner according to Embodiment 1 will be described. The air conditioner according to the first embodiment is a simultaneous heating and cooling type air conditioner in which a plurality of indoor units can simultaneously perform both the cooling operation and the heating operation.

[Installation example of air conditioner]
FIG. 1 is a schematic view showing an installation example of the air conditioner 1 according to the first embodiment. As shown in FIG. 1, the air conditioner 1 is a branch unit interposed between an outdoor unit 10 as a heat source unit, a plurality of indoor units 20A and 20B, and the outdoor unit 10 and a plurality of indoor units 20A and 20B. It has 30 and. The outdoor unit 10 and the branch unit 30 are connected by a high pressure pipe 40 and a low pressure pipe 50. Further, the branch unit 30 and the plurality of indoor units 20A and 20B are connected by the indoor unit side gas piping 60 and the refrigerant piping 70, respectively. Thus, a refrigerant circuit in which the refrigerant circulates in each of the pipes is formed.

  In this example, two indoor units 20A and 20B are connected to the branch unit 30. In the following description, the indoor units 20A and 20B are simply referred to as "indoor units 20" as appropriate, unless it is necessary to distinguish them. Moreover, when calling it "indoor unit 20", both single or multiple shall be included.

  The outdoor unit 10 is usually installed in a space outside the building 2 such as a building, for example, the outdoor space 3 which is a rooftop or the like. The outdoor unit 10 generates cold or warm heat, and supplies the generated cold or warm heat to the indoor unit 20 via the branch unit 30.

  The indoor unit 20 uses the cooling or heating air supplied from the outdoor unit 10 via the branching unit 30 in a space inside the building 2, for example, in an air conditioning target space such as a room or a server room, by cooling air or heating air. Supply to a certain indoor space 4. In this example, the indoor unit 20 is installed in a space 5 such as a ceiling, which is a space inside the building 2 but different from the indoor space 4. The indoor unit 20 can also be used, for example, as floor heating which is installed under the floor and warms the floor surface by the heat supplied during heating operation.

  The branch unit 30 is configured to be able to be installed at a position different from the outdoor space 3 and the indoor space 4, for example, the space 5 or the like, as a casing different from the outdoor unit 10 and the indoor unit 20. The branch unit 30 is connected to the outdoor unit 10 by the high pressure piping 40 and the low pressure piping 50, and is connected to the indoor units 20 by the indoor unit side gas piping 60 and the refrigerant piping 70, respectively. The branch unit 30 is for transferring the cold or warm heat generated by the outdoor unit 10 to the indoor unit 20.

  The number of indoor units 20 connected to the branch unit 30 is not limited to this example, and one indoor unit 20 may be connected, for example, or three or more indoor units 20 may be connected. . Also, for example, a plurality of outdoor units 10 may be provided, and one or more indoor units 20 may be connected to the plurality of outdoor units 10. That is, the number of outdoor units 10 and the number of indoor units 20 can be appropriately determined according to the size of the building 2 in which the air conditioner 1 is installed.

  Here, in the air conditioner 1 of Embodiment 1, for example, a non-azeotropic mixture refrigerant, a pseudo-azeotropic mixture refrigerant, a single refrigerant, or the like can be used as the refrigerant to be circulated through the refrigerant circuit. The non-azeotropic mixed refrigerant includes R-407C, which is a HFC (hydrofluorocarbon) refrigerant. Since this non-azeotropic mixture refrigerant is a refrigerant having a different boiling point, it has a characteristic that the composition ratio of the liquid phase refrigerant and the gas phase refrigerant is different. The pseudo-azeotropic mixture refrigerant includes HFC refrigerant R-410A or R-404A. This quasi-azeotropic mixed refrigerant has the characteristic of about 1.6 times the operating pressure of R-22, which is a single refrigerant, in addition to the same characteristics as the non-azeotropic mixed refrigerant. Examples of the single refrigerant include R-22 which is a HCFC (hydrochlorofluorocarbon) refrigerant, R-134a which is an HFC refrigerant, and the like. This single refrigerant is characterized as being easy to handle because it is not a mixture.

Besides this, natural refrigerants such as CO ₂ (carbon dioxide), propane, isobutane, ammonia and the like can also be used as the refrigerant to be circulated through the refrigerant circuit, and the refrigerant according to the application and purpose of the air conditioner 1 Can be used.

[Circuit configuration of air conditioner]
FIG. 2: is schematic which shows an example of a circuit structure of the air conditioner 1 shown in FIG. In the example of FIG. 2, the case where the air conditioner 1 is comprised by one outdoor unit 10, one branch unit 30, and two indoor units 20A and 20B is shown. As described above, the numbers of the outdoor units 10 and the indoor units 20 are not limited to this example.

(Outdoor unit)
The outdoor unit 10 includes a compressor 11, a refrigerant flow switching device 12, a heat source side heat exchanger 13, an accumulator 14, and four check valves 15a to 15d.

  The compressor 11 sucks in a low-temperature low-pressure refrigerant, compresses the refrigerant to a high-temperature high-pressure state, and discharges the refrigerant. As the compressor 11, for example, an inverter compressor or the like capable of controlling the capacity, which is the refrigerant delivery amount per unit time, can be used by arbitrarily changing the drive frequency.

  The refrigerant flow switching device 12 is, for example, a four-way valve, and switches the cooling operation and the heating operation by switching the flow direction of the refrigerant. The refrigerant flow switching device 12 is not limited to the four-way valve described above, and may be used in combination with other valves, for example.

  The heat source side heat exchanger 13 performs heat exchange between air and a refrigerant supplied from an air blower (not shown) such as a fan (hereinafter referred to as "outdoor air" as appropriate). Specifically, the heat source side heat exchanger 13 functions as a condenser that radiates the heat of the refrigerant to the outdoor air and condenses the refrigerant during the cooling operation. The heat source side heat exchanger 13 functions as an evaporator that evaporates the refrigerant during the heating operation and cools the outdoor air by the heat of vaporization at that time.

  The accumulator 14 is provided on the low pressure side which is the suction side of the compressor 11. The accumulator 14 stores surplus refrigerant generated due to the difference between the cooling operation and the heating operation, surplus refrigerant with respect to transient operation change, and the like.

  The check valves 15a to 15d allow the flow of the refrigerant flowing in the refrigerant circuit only in a predetermined direction. The check valve 15 a is provided in the low pressure pipe 50 between the branch unit 30 and the refrigerant flow switching device 12, and the refrigerant is separated from the branch unit 30 to the outdoor unit 10 during cooling operation including full cooling operation and cooling main operation described later. Distribute in the direction of The check valve 15b is provided in a first connection pipe 31a that connects the high pressure pipe 40 and the low pressure pipe 50, and the compressor returns the refrigerant returned from the branch unit 30 during heating operation including heating only operation and heating main operation. Distribute to the 11 suction side.

  The check valve 15 c is provided in a second connection pipe 31 b that connects the high pressure pipe 40 and the low pressure pipe 50, and distributes the refrigerant discharged from the compressor 11 to the branch unit 30 during the heating operation. The check valve 15 d is provided in the high pressure pipe 40 between the heat source side heat exchanger 13 and the branch unit 30 and distributes the refrigerant in the direction from the outdoor unit 10 to the branch unit 30 during the cooling operation.

(Indoor unit)
The indoor units 20A and 20B, for example, perform cooling and heating of the air in the space to be air conditioned. The indoor unit 20A is configured of the expansion device 21A and the use side heat exchanger 22A. The indoor unit 20B is configured by the expansion device 21B and the use side heat exchanger 22B.

  In the following description, when it is not necessary to distinguish the expansion devices 21A and 21B in particular, the expansion devices 21A and 21B will be referred to simply as “the expansion device 21”. Similarly, the use side heat exchangers 22A and 22B will be simply referred to as the “use side heat exchanger 22”. When referred to as the “throttling device 21” or the “use-side heat exchanger 22”, each includes one or more of them.

  The expansion device 21 decompresses and expands the refrigerant by adjusting the flow rate of the refrigerant. The expansion device 21 is configured of, for example, a valve capable of controlling the opening degree such as an electronic expansion valve. In addition, as the expansion device 21, not only this but other expansion devices, such as a capillary, can also be used, for example.

  The use side heat exchanger 22 performs heat exchange between the air and the refrigerant supplied by a blower such as a fan (not shown). As a result, the heating air or the cooling air supplied to the indoor space 4 is generated. Specifically, the use-side heat exchanger 22 functions as an evaporator when the refrigerant is carrying cold energy during the cooling operation, and cools air by cooling the air in the indoor space 4 that is the space to be air-conditioned. Do. In addition, the use side heat exchanger 22 functions as a condenser when the refrigerant conveys heat during heating operation, and heats the air in the indoor space 4 by heating.

(Branch unit)
The branch unit 30 has a function of supplying the indoor unit 20 with cold or warm heat supplied from the outdoor unit 10. The branch unit 30 includes a gas-liquid separator 31, flow path switching valves 100A and 100B, and throttling devices 32 and 33. The flow path switching valves 100A and 100B are provided in the number corresponding to the number of indoor units 20 connected to the branch unit 30.

  The flow path switching valves 100A and 100B switch the flow of the refrigerant supplied to the indoor unit 20. By switching the refrigerant flow paths by the flow path switching valves 100A and 100B, the indoor units 20A and 20B connected to the branch unit 30 can simultaneously execute the cooling operation and the heating operation. The flow path switching valves 100A and 100B are configured by, for example, three-way valves. The details of the flow path switching valves 100A and 100B will be described later. In the following description, when it is not necessary to distinguish between the flow passage switching valves 100A and 100B, the flow passage switching valve 100 will be referred to as appropriate.

  One of the flow path switching valves 100A is connected to the low pressure pipe 50, the other is connected to the high pressure gas pipe 80, and the other is connected to the indoor unit side pipe 60a. Further, one of the flow path switching valve 100B is connected to the low pressure pipe 50, the other is connected to the high pressure gas pipe 80, and the other is connected to the indoor unit side pipe 60b. The flow control valves 90A and 100B are controlled by the controller 90 to open and close the valves.

  The gas-liquid separator 31 is connected to the high pressure piping 40 and is connected to each of the inflow and the outflow of the indoor unit 20. The gas-liquid separator 31 has a function of separating the inflowing refrigerant into a gas refrigerant and a liquid refrigerant.

  The expansion device 32 is provided between the gas-liquid separator 31 and the expansion device 21A of the indoor unit 20A and the expansion device 21B of the indoor unit 20B, and decompresses and expands the refrigerant. The throttling device 33 is provided in a connecting pipe that connects the low pressure piping 50 and the piping between the throttling device 32 and the throttling device 21A of the indoor unit 20A and the throttling device 21B of the indoor unit 20B. It is to expand. The throttling device 32 and the throttling device 33 are constituted by, for example, valves capable of controlling the opening degree such as a capillary or an electronic expansion valve. When the throttle device 32 and the throttle device 33 are expansion valves, the valve opening degree is controlled by the controller 90.

(Control device)
The air conditioner 1 is provided with a control device 90. The control device 90 is composed of, for example, software executed on an arithmetic device such as a microcomputer and a CPU (Central Processing Unit), hardware such as a circuit device for realizing various functions, and the like. Control. For example, the control device 90 controls the compressor frequency of the compressor 11, the valve opening degree of the expansion device 21, the switching of the flow path switching valves 100A and 100B, and the like based on the operation content and the like instructed by the user.

[Configuration of flow path switching valve]
FIG. 3 is a schematic view showing an example of the configuration of the flow path switching valve 100 according to the first embodiment. As shown in FIG. 3, the flow path switching valve 100 includes shutoff valves 101 and 102, a flow path switching circuit 103, and a flow path switching valve drive circuit 110. Further, in the first embodiment, the flow path switching valve 100 is formed in a state in which the low pressure pipe 50 and the high pressure gas pipe 80 are also included in the components.

  The shutoff valve 101 is provided between the flow passage 105 a branched from the indoor unit side gas piping 60 and the low pressure piping 50. The shutoff valve 101 is connected to a bleed port 106 a as a refrigerant suction pipe. The shutoff valve 101 allows or blocks the flow of the refrigerant between the flow passage 105 a and the low pressure piping 50 by opening and closing according to the differential pressure between the pressure on the flow passage 105 a side and the pressure on the low pressure piping 50 side. For example, the shutoff valve 101 is in the "closed" state when the refrigerant is drawn into the bleed port 106a and the above-described differential pressure is reduced, and is in the "opened" state when the differential pressure is increased.

  The shutoff valve 102 is provided between the high pressure gas pipe 80 and the flow path 105 b branched from the indoor unit side gas pipe 60. The shutoff valve 102 is connected to a bleed port 106b as a refrigerant suction pipe. The shutoff valve 102 allows or blocks the flow of the refrigerant between the flow passage 105b and the high pressure gas piping 80 by opening and closing according to the differential pressure between the pressure on the flow passage 105b and the pressure on the high pressure gas piping 80 side. Do. For example, the shutoff valve 102 is in the “closed” state when the refrigerant is drawn into the bleed port 106 b and the above-described differential pressure is reduced, and is in the “opened” state when the differential pressure is increased.

  The indoor unit side gas pipe 60 is connected to the indoor unit 20. During the cooling operation, low-pressure gas refrigerant flows from the indoor unit 20 into the flow path switching valve 100 via the indoor unit side gas pipe 60. Further, during the heating operation, high-pressure gas refrigerant flows out from the flow path switching valve 100 to the indoor unit 20 via the indoor unit side gas pipe 60.

  The low pressure pipe 50 is connected to the outdoor unit 10 on the downstream side, and the gas refrigerant or the two-phase refrigerant flows out of the flow path switching valve 100 to the outdoor unit 10 through the low pressure pipe 50. The high-pressure gas pipe 80 is connected to the gas-liquid separator 31 on the upstream side, and a high-pressure gas refrigerant flows from the gas-liquid separator 31 into the flow path switching valve 100 via the high-pressure gas pipe 80.

  The flow path switching circuit 103 is connected to the low pressure side suction flow path 104 connected to the low pressure pipe 50, the flow path 105c, and the bleed ports 106a and 106b. In the flow path switching circuit 103, a cylinder whose inside is hollow is provided in the valve. The flow path switching circuit 103 can switch the flow path through which the refrigerant flows by moving the cylinder.

  The flow path switching valve drive circuit 110 is provided to drive a cylinder in the flow path switching circuit 103, and generates a voltage for operating the cylinder. Although the output system of the voltage in the flow path switching valve drive circuit 110 is not limited, in this example, the flow path switching valve drive circuit 110 outputs, for example, a voltage of about DC 20 V which has no possibility of firing. Further, for example, when it is not necessary to consider ignition, the flow path switching valve drive circuit 110 may output a voltage of, for example, about 200 V AC.

[Structure of flow path switching valve]
FIG. 4 is a schematic view showing an example of the structure of the flow path switching valve 100 shown in FIG. In the following, the vertical direction when viewing FIG. 4 from the front is referred to as the “height direction”, the horizontal direction is referred to as the “width direction”, and the direction from the front to the back is referred to as the “depth method” Do. Moreover, in the following drawings, the relationship of the magnitude | size of each structural member may differ from an actual thing including FIG.

  As shown in FIG. 4, in the flow path switching valve 100, the shutoff valves 101 and 102, the flow path switching circuit 103, and the flow path switching valve drive circuit 110 are accommodated in a valve main body 120 that forms an outer shell. Further, a low pressure pipe 50, an indoor unit side gas pipe 60, and a high pressure gas pipe 80 are connected to the flow path switching valve 100. The shutoff valves 101 and 102, the flow path switching circuit 103, the low pressure piping 50, the indoor unit side gas piping 60, and the high pressure gas piping 80 are made of a valve body 120 using a flame retardant material such as brass or aluminum. It is integrally formed with.

  Each of the shutoff valves 101 and 102 and the flow path switching circuit 103 is disposed to face the front. In this example, the shutoff valve 101 and the flow path switching circuit 103 are arranged on the bottom side of the valve body 120 so as to be aligned in the width direction, and the shutoff valve 102 is arranged on the top side of the valve body 120.

  The low pressure piping 50 and the high pressure gas piping 80 are formed, for example, in the depth direction so as to be parallel to each other. Further, the indoor unit side gas piping 60 is formed, for example, to be orthogonal to the low pressure piping 50 and the high pressure gas piping 80 and to be horizontal to the bottom surface of the valve body 120. Thus, by forming the indoor unit side gas pipe 60 so as to be horizontal to the bottom surface of the valve main body 120, the height of the flow path switching valve 100 can be suppressed.

  The flow path switching circuit 103 is provided with a flow path switching valve coil 111. The flow path switching valve coil 111 is provided to receive the voltage output from the flow path switching valve drive circuit 110 and operate the cylinder of the flow path switching circuit 103.

  Vibration prevention springs 112 and 113 are provided for the shutoff valves 101 and 102, respectively. Generally, in the shutoff valves 101 and 102, when the flow of the circulating refrigerant is small, the self-oscillation operation of the valve may occur. Since the self-oscillating vibration operation of the valve generates so-called "catastrophic noise", for example, when the branching unit 30 is installed in a space such as a ceiling of a living room, there is a possibility that the occupant may feel uncomfortable. Therefore, in the first embodiment, vibration preventing springs 112 and 113 are provided to prevent the self-excited vibration operation of the valves generated when the flow rate of the refrigerant flowing to each of shut off valves 101 and 102 is small. It is done.

  In addition, when the self-oscillation vibration operation of such a valve does not have a problem, or when the flow path switching valve 100 is not used in a region where the self-oscillation vibration operation occurs, the vibration prevention springs 112 and 113 are not used. It is also good.

  FIG. 5 is a schematic view showing another example of the structure of the flow path switching valve 100 shown in FIG. In the flow path switching valve 100 shown in FIG. 5, the direction in which the indoor unit side gas pipe 60 is formed is different from the flow path switching valve 100 shown in FIG. 4. The other parts are formed in the same manner as the flow path switching valve 100 shown in FIG.

  The indoor unit side gas pipe 60 is formed to be, for example, perpendicular to the bottom surface of the valve body 120. Thus, by forming the indoor unit side gas piping 60 so as to be perpendicular to the bottom surface of the valve main body 120, the length in the width direction of the flow path switching valve 100 can be suppressed.

[Operation of air conditioner]
Next, the operation of the refrigerant in various operation modes in the air conditioner 1 having the above configuration will be described. As the operation mode in the air conditioner 1 according to the first embodiment, a cooling only operation mode in which both indoor units 20A and 20B perform cooling operation, a heating only operation mode in which heating operation is performed, indoor units 20A and 20B There are a cooling main operation mode and a heating main operation mode in which both the cooling operation and the heating operation are simultaneously performed, and either one operation is mainly performed.

(Full cooling operation mode)
First, the operation of the refrigerant in the cooling only operation mode will be described. In the cooling only operation mode, the indoor units 20A and 20B both perform the cooling operation.

  In the cooling only operation mode, the refrigerant flow switching device 12 in the outdoor unit 10 is switched to the state shown by the solid line in FIG. Then, the low-temperature low-pressure refrigerant is compressed by the compressor 11 and discharged as a high-temperature high-pressure gas refrigerant.

  The high temperature and high pressure gas refrigerant discharged from the compressor 11 flows into the heat source side heat exchanger 13 via the refrigerant flow switching device 12. The high-temperature, high-pressure gas refrigerant flowing into the heat source side heat exchanger 13 exchanges heat with the outdoor air, condenses while radiating heat, becomes high-pressure liquid refrigerant, and flows out from the heat source side heat exchanger 13.

  The high-pressure liquid refrigerant flowing out of the heat source side heat exchanger 13 flows out of the outdoor unit 10 via the check valve 15 d and flows into the branch unit 30. The high-pressure liquid refrigerant flowing into the branch unit 30 flows out of the branch unit 30 through the gas-liquid separator 31 and the expansion device 32, and flows into the indoor units 20A and 20B.

  The high pressure liquid refrigerant flowing into the indoor unit 20A is decompressed and expanded by the expansion device 21A to become a low pressure gas-liquid two-phase refrigerant or liquid refrigerant, and flows into the use side heat exchanger 22A. The low-pressure gas-liquid two-phase refrigerant or liquid refrigerant flowing into the use side heat exchanger 22A exchanges heat with room air, absorbs heat and evaporates to cool the room air, and becomes a low-pressure gas refrigerant to use side heat It flows out of the exchanger 22A.

  The high-pressure liquid refrigerant flowing into the indoor unit 20B is decompressed and expanded by the expansion device 21B to become a low-pressure gas-liquid two-phase refrigerant or liquid refrigerant, and flows into the use-side heat exchanger 22B. The low-pressure gas-liquid two-phase refrigerant or liquid refrigerant flowing into the use side heat exchanger 22B exchanges heat with room air, absorbs heat and evaporates to cool the room air, and becomes a low-pressure gas refrigerant to use side heat It flows out of the exchanger 22B.

  The low-pressure gas refrigerant flowing out of the use side heat exchanger 22A flows out of the branch unit 30 via the flow path switching valve 100A and flows into the outdoor unit 10. Further, the low pressure gas refrigerant flowing out of the use side heat exchanger 22B flows out of the branch unit 30 via the flow path switching valve 100B, and flows out of the branch unit 30 via the flow path switching valve 100A. And flows into the outdoor unit 10.

  The low-pressure gas refrigerant that has flowed into the outdoor unit 10 passes through the check valve 15 a, the refrigerant flow switching device 12 and the accumulator 14 and is drawn into the compressor 11. Then, the above-described circulation is repeated.

(All heating operation mode)
Next, the operation of the refrigerant in the heating only operation mode will be described. In the heating only operation mode, the indoor units 20A and 20B both perform heating operation.

  In the heating only operation mode, the refrigerant flow switching device 12 in the outdoor unit 10 is switched to the state shown by the dotted line in FIG. Then, the low-temperature low-pressure refrigerant is compressed by the compressor 11 and discharged as a high-temperature high-pressure gas refrigerant.

  The high temperature and high pressure gas refrigerant discharged from the compressor 11 flows out of the outdoor unit 10 through the refrigerant flow switching device 12 and the check valve 15 c and flows into the branch unit 30. The high temperature and high pressure gas refrigerant flowing into the branch unit 30 flows out of the branch unit 30 through the gas-liquid separator 31 and the flow path switching valves 100A and 100B, and flows into the indoor units 20A and 20B.

  The high-temperature, high-pressure gas refrigerant flowing into the indoor unit 20A flows into the use-side heat exchanger 22A, exchanges heat with the room air, condenses while radiating heat, heats the room air, and becomes a high-pressure liquid refrigerant It flows out from use side heat exchanger 22A. The high-pressure liquid refrigerant flowing out of the use side heat exchanger 22A is decompressed and expanded by the expansion device 21A to become a low-pressure gas-liquid two-phase refrigerant or liquid refrigerant, and flows out from the indoor unit 20A.

  In addition, the high temperature / high pressure gas refrigerant flowing into the indoor unit 20B flows into the use side heat exchanger 22B, exchanges heat with the room air, condenses while radiating heat, and heats the room air, so that high pressure liquid refrigerant And then flow out of the use side heat exchanger 22B. The high-pressure liquid refrigerant flowing out of the use side heat exchanger 22B is decompressed and expanded by the expansion device 21B to become a low-pressure gas-liquid two-phase refrigerant or liquid refrigerant, and flows out from the indoor unit 20B.

  The low-pressure gas-liquid two-phase refrigerant or liquid refrigerant flowing out of the indoor units 20A and 20B flows into the branch unit 30, flows out of the branch unit via the expansion device 33, and flows into the outdoor unit 10.

  The low-pressure gas-liquid two-phase refrigerant or liquid refrigerant flowing into the outdoor unit 10 flows into the heat source side heat exchanger 13 via the check valve 15 b. The low-pressure gas-liquid two-phase refrigerant or liquid refrigerant flowing into the heat source side heat exchanger 13 exchanges heat with outdoor air, absorbs heat and evaporates, and turns out as a low-temperature low-pressure gas refrigerant and flows out from the heat source side heat exchanger 13 .

  The low-temperature low-pressure gas refrigerant flowing out of the heat source side heat exchanger 13 passes through the refrigerant flow switching device 12 and the accumulator 14 and is sucked into the compressor 11. Then, the above-described circulation is repeated.

(Cooling-based operation mode)
Next, the operation of the refrigerant in the cooling main operation mode will be described. Here, the case where the indoor unit 20A performs the cooling operation and the indoor unit 20B performs the heating operation will be described as an example.

  In the cooling main operation mode, the refrigerant flow switching device 12 in the outdoor unit 10 is switched to the state shown by the solid line in FIG. Then, the low-temperature low-pressure refrigerant is compressed by the compressor 11 and discharged as a high-temperature high-pressure gas refrigerant.

  The high temperature and high pressure gas refrigerant discharged from the compressor 11 flows into the heat source side heat exchanger 13 via the refrigerant flow switching device 12. The high temperature and high pressure gas refrigerant flowing into the heat source side heat exchanger 13 exchanges heat with the outdoor air, condenses while radiating heat, and becomes a high pressure gas-liquid two-phase refrigerant and flows out from the heat source side heat exchanger 13.

  The high-pressure gas-liquid two-phase refrigerant flowing out of the heat source side heat exchanger 13 flows out of the outdoor unit 10 via the check valve 15 d and flows into the branch unit 30. The high-pressure gas-liquid two-phase refrigerant flowing into the branch unit 30 flows into the gas-liquid separator 31, and is separated into a high-pressure gas refrigerant and a high-pressure liquid refrigerant.

  The high-pressure gas refrigerant separated by the gas-liquid separator 31 flows out of the branch unit 30 via the flow path switching valve 100B and flows into the indoor unit 20B. The high-pressure gas refrigerant that has flowed into the indoor unit 20B flows into the use-side heat exchanger 22B, exchanges heat with the room air, condenses while radiating heat, thereby heating the room air and using it as a high-pressure liquid refrigerant It flows out from the side heat exchanger 22B. The high pressure liquid refrigerant flowing out of the use side heat exchanger 22B is decompressed and expanded by the expansion device 21B to become a gas-liquid two-phase refrigerant or liquid refrigerant at an intermediate pressure, and flows out from the indoor unit 20B.

  On the other hand, the high-pressure liquid refrigerant separated by the gas-liquid separator 31 and the gas-liquid two-phase refrigerant or liquid refrigerant having an intermediate pressure flowing out of the indoor unit 20B flow out of the branch unit 30 and flow into the indoor unit 20A. The high-pressure liquid refrigerant flowing into the indoor unit 20A and the gas-liquid two-phase refrigerant or liquid refrigerant having an intermediate pressure flowing out from the indoor unit 20B are decompressed and expanded by the expansion device 21A and the low-pressure gas-liquid two-phase refrigerant or liquid refrigerant And flows into the use side heat exchanger 22A.

  The low-pressure gas-liquid two-phase refrigerant or liquid refrigerant flowing into the use side heat exchanger 22A exchanges heat with room air, absorbs heat and evaporates to cool the room air, and becomes a low-pressure gas refrigerant to use side heat It flows out of the exchanger 22A. The low-pressure gas refrigerant flowing out of the use side heat exchanger 22A flows out of the branch unit 30 via the flow path switching valve 100A and flows into the outdoor unit 10.

  The low-pressure gas refrigerant that has flowed into the outdoor unit 10 passes through the check valve 15 a, the refrigerant flow switching device 12 and the accumulator 14 and is drawn into the compressor 11. Then, the above-described circulation is repeated.

(Heating main operation mode)
Next, the operation of the refrigerant in the heating main operation mode will be described. Here, as in the cooling main operation mode, the case where the indoor unit 20A performs the cooling operation and the indoor unit 20B performs the heating operation will be described as an example.

  In the heating main operation mode, the refrigerant flow switching device 12 in the outdoor unit 10 is switched to the state shown by the dotted line in FIG. Then, the low-temperature low-pressure refrigerant is compressed by the compressor 11 and discharged as a high-temperature high-pressure gas refrigerant.

  The high temperature and high pressure gas refrigerant discharged from the compressor 11 flows out of the outdoor unit 10 through the refrigerant flow switching device 12 and the check valve 15 c and flows into the branch unit 30. The high temperature and high pressure gas refrigerant flowing into the branch unit 30 flows out of the branch unit 30 via the gas-liquid separator 31 and the flow path switching valve 100B.

  The high-temperature and high-pressure gas refrigerant flowing out of the branch unit 30 flows into the indoor unit 20B. The high-temperature, high-pressure gas refrigerant flowing into the indoor unit 20B flows into the use-side heat exchanger 22B, exchanges heat with the room air, condenses while radiating heat and heats the room air, and becomes a high-pressure liquid refrigerant It flows out of the use side heat exchanger 22B. The high pressure liquid refrigerant flowing out of the use side heat exchanger 22B is decompressed and expanded by the expansion device 21B to become a gas-liquid two-phase refrigerant or liquid refrigerant at an intermediate pressure, and flows out from the indoor unit 20B.

  The gas-liquid two-phase refrigerant or liquid refrigerant having an intermediate pressure that has flowed out of the indoor unit 20B flows into the indoor unit 20A. The gas-liquid two-phase refrigerant or liquid refrigerant having an intermediate pressure flowing into the indoor unit 20A is decompressed and expanded by the expansion device 21A to become a low pressure gas-liquid two-phase refrigerant or liquid refrigerant, and flows into the use side heat exchanger 22A.

  The low-pressure gas-liquid two-phase refrigerant or liquid refrigerant flowing into the use side heat exchanger 22A exchanges heat with room air, absorbs heat and evaporates to cool the room air, and becomes a low-pressure gas refrigerant to use side heat It flows out of the exchanger 22A. The low-pressure gas refrigerant flowing out of the use side heat exchanger 22A flows out of the branch unit 30 via the flow path switching valve 100A and flows into the outdoor unit 10.

  The low-pressure gas refrigerant that has flowed into the outdoor unit 10 flows into the heat source side heat exchanger 13 via the check valve 15 b. The low-pressure gas refrigerant that has flowed into the heat source side heat exchanger 13 exchanges heat with the outdoor air, absorbs heat and evaporates, and becomes a low-temperature low-pressure gas refrigerant and flows out of the heat source side heat exchanger 13.

  The low-temperature low-pressure gas refrigerant flowing out of the heat source side heat exchanger 13 passes through the refrigerant flow switching device 12 and the accumulator 14 and is sucked into the compressor 11. Then, the above-described circulation is repeated.

[Operation of flow path switching valve]
Next, operations in the various operation modes of the flow path switching valve 100 will be described. Here, the operation of the flow path switching valve 100 in the cooling operation mode, the heating operation mode, and the case where the heating operation mode is switched to the cooling operation mode will be described. FIG. 6 is a schematic view showing the state of each flow passage and cylinder in the flow passage switching valve 100 of FIG.

(In the cooling operation mode)
In the cooling operation mode, first, the states of the respective flow paths and cylinders in the flow path switching valve 100 are set as shown in FIG. When the low pressure gas refrigerant flows from the indoor unit side gas pipe 60 into the flow path switching valve 100, the refrigerant is drawn from the bleed port 106a into the low pressure side suction flow path 104, and the shutoff valve 101 is in the "open" state. As a result, the refrigerant flowing from the indoor unit side gas pipe 60 passes through the shutoff valve 101 and flows out to the low pressure pipe 50.

  The refrigerant flowing from the indoor unit side gas pipe 60 also flows into the flow path 105 c and flows out to the low pressure pipe 50 via the flow path 105 c and the low pressure side suction flow path 104. Then, the refrigerant flowing out through the two paths merges in the low pressure pipe 50.

(In heating operation mode)
In the heating operation mode, first, the states of the flow paths and the cylinders in the flow path switching valve 100 are set as shown in FIG. When the high pressure gas refrigerant flows from the high pressure gas pipe 80 into the flow path switching valve 100, the refrigerant is drawn from the bleed port 106b into the low pressure side suction flow path 104, and the shutoff valve 102 is in the "open" state. Thus, the refrigerant flowing from the high pressure gas pipe 80 passes through the shutoff valve 102 and flows out from the indoor unit side gas pipe 60.

(When switching from heating operation mode to cooling operation mode)
When the operation mode is switched from the heating operation mode to the cooling operation mode, the high pressure refrigerant is not discharged but retained in the indoor unit side gas piping 60, and the residual pressure remains. Therefore, when the cooling operation is performed immediately after the heating operation, the difference between the residual pressure due to the refrigerant staying in the indoor unit side gas piping 60 and the pressure of the low pressure piping 50 is large. Therefore, when the operation mode is switched to open the shutoff valve 101, a loud flow noise of the gas refrigerant may be generated due to the pressure difference. Such flow noise may cause discomfort to the resident. Therefore, in the first embodiment, when the operation mode is switched from the heating operation mode to the cooling operation mode, the residual pressure of the indoor unit side gas piping 60 is reduced using the flow path 105c.

  In this case, specifically, first, the cylinder in the flow path switching circuit 103 is set as shown in FIG. When the cylinder is set in this manner, the indoor unit side gas pipe 60 and the low pressure side lead-in channel 104 are connected, and a path is formed where the indoor unit side gas pipe 60 and the low pressure pipe 50 are connected. Then, the refrigerant accumulated in the indoor unit side gas piping 60 flows out to the low pressure piping 50 via the low pressure side inlet channel 104. Thereby, the residual pressure of the indoor unit side gas piping 60 is reduced. Therefore, generation | occurrence | production of the flow noise by the refrigerant | coolant which stays in indoor unit side gas piping 60 which was mentioned above can be suppressed.

  In addition, it is possible to suppress generation | occurrence | production of the flow noise by the refrigerant | coolant which stays in the indoor unit side gas piping 60 not only by the method mentioned above but using the cutoff valve 101, for example. However, if the flow passage diameter is large as in the case of the shutoff valve 101, the above-described gas flow noise is generated when control is performed to extract the refrigerant remaining in the indoor unit side gas pipe 60. In order to suppress the generation of gas flow noise, it is not appropriate to use the shutoff valve 101 in this way because a valve for discharging the low flow rate refrigerant is required.

  As described above, the flow path switching valve 100 according to the first embodiment is provided between the indoor unit side gas pipe 60 in which the refrigerant flows in and out and the low pressure pipe 50 in which the refrigerant flows out, and allows the refrigerant to flow. Alternatively, the shutoff valve 101 for shutting off, the shutoff valve 102 provided between the indoor unit side gas piping 60 and the high pressure gas piping 80 where the refrigerant flows in, and for permitting or blocking the flow of the refrigerant, at least the indoor unit side gas piping 60 A flow path switching circuit 103 for switching the connection of the flow path between the low-pressure pipe 50 and the shut-off valve 101 connected to the indoor unit side gas pipe 60, the low-pressure pipe 50 and the shut-off valve 101; And a flow path switching valve drive circuit 110 for driving the flow path switching valve drive circuit 110 so as to draw the refrigerant flowing into the shutoff valve 101 into the low pressure pipe 50. By connecting the flow path and the low-pressure pipe 50 which communicates with the shut-off valve 101 in the road 103 and a flow path communicating, to open the shut-off valve 101.

  As described above, in the first embodiment, the flow path switching circuit 103 is driven to control the opening and closing of the shutoff valve 101. The voltage required to drive the flow path switching circuit 103 may be lower than, for example, the voltage required to drive the solenoid valve, so that ignition due to the occurrence of an arc can be suppressed.

  Further, since the ignition can be suppressed, the drain pan or the exterior provided in the branch unit 30 provided with the flow path switching valve 100 can be changed to an inexpensive material such as foamable polystyrene having a burning property.

  Further, in the flow path switching valve 100 according to the first embodiment, the indoor unit side gas piping 60 is formed to be parallel to the bottom surface of the valve main body 120. Thereby, the height of the flow path switching valve 100 can be suppressed, and the degree of freedom of installation of the branch unit 30 provided with the flow path switching valve 100 can be improved.

  Furthermore, in the flow path switching valve 100 according to the first embodiment, the indoor unit side gas piping 60 is formed to be perpendicular to the bottom surface of the valve main body 120. Thus, the length in the width direction of the flow path switching valve 100 can be suppressed, and the degree of freedom in the installation of the branch unit 30 provided with the flow path switching valve 100 can be improved.

  Furthermore, in the flow path switching valve 100 according to the first embodiment, the shutoff valves 101 and 102 and the flow path switching circuit 103 are arranged to face the front of the valve body 120. Thereby, the accessibility of the valve and the coil for driving the valve by the operator can be improved, and the operation such as maintenance can be easily performed.

Second Embodiment
Next, an air conditioner according to Embodiment 2 will be described. The air conditioner according to the second embodiment differs from the first embodiment in the configuration of the flow path switching valve 100. In the following description, parts in common with the first embodiment described above are assigned the same reference numerals and descriptions thereof will be omitted.

  The air conditioner 1 in the second embodiment has the configuration of FIG. 1 and FIG. 2 as in the first embodiment, so the description is omitted here.

[Configuration of flow path switching valve]
FIG. 7 is a schematic view showing an example of the configuration of the flow path switching valve 100 according to the second embodiment. As shown in FIG. 7, the flow path switching valve 100 includes shutoff valves 101 and 102, a flow path switching circuit 103, and a flow path switching valve drive circuit 110. Unlike the flow path switching valve 100 according to the first embodiment, the flow path switching valve 100 excludes the low pressure pipe 50 and the high pressure gas pipe 80 from the components. Thereby, the material used for flow-path switching valve 100, such as brass or aluminum, can be reduced.

  As described above, in the second embodiment, the same effect as the first embodiment can be obtained. Moreover, since the low pressure piping 50 and the high pressure gas piping 80 which are formed in the flow path switching valve 100 can be removed from the components and the material used for the flow path switching valve 100 can be reduced, the cost can be suppressed.

Third Embodiment
Next, an air conditioner according to Embodiment 3 will be described. The air conditioner according to Embodiment 3 is different from Embodiments 1 and 2 in that the shutoff valve 102 in the flow path switching valve 100 is configured by a solenoid valve. In the following description, parts in common with the first and second embodiments described above are assigned the same reference numerals and descriptions thereof will be omitted.

  The air conditioner 1 in the third embodiment has the configuration of FIG. 1 and FIG. 2 as in the first embodiment, so the description is omitted here.

[Configuration of flow path switching valve]
FIG. 8 is a schematic view showing an example of the configuration of the flow path switching valve 100 according to the third embodiment.
As shown in FIG. 8, the flow path switching valve 100 includes shutoff valves 101 and 102, a flow path switching circuit 103, and a flow path switching valve drive circuit 110.

  As in the first embodiment, the shutoff valve 101 is provided between the flow passage 105a and the low pressure pipe 50, and the bleed port 106a is connected. The shutoff valve 101 allows or blocks the flow of the refrigerant between the flow passage 105 a and the low pressure piping 50 by opening and closing according to the differential pressure between the pressure on the flow passage 105 a side and the pressure on the low pressure piping 50 side. For example, the shutoff valve 101 is in the "closed" state when the refrigerant is drawn into the bleed port 106a and the above-described differential pressure is reduced, and is in the "opened" state when the differential pressure is increased.

  The shutoff valve 102 is provided between the flow passage 105 b and the high pressure gas pipe 80. The shutoff valve 102 is, for example, an electromagnetic valve whose opening and closing are controlled by a flow path switching valve drive circuit 110 described later, and allows or blocks the flow of the refrigerant between the flow path 105b and the high pressure gas pipe 80. .

  To the flow path switching circuit 103, the low pressure side suction flow path 104, the flow path 105c, and the bleed port 106a are connected. In the flow path switching circuit 103, a cylinder is provided in the valve. The flow path switching circuit 103 can switch the flow path through which the refrigerant flows by moving the cylinder.

  The flow path switching valve drive circuit 110 is provided to drive a cylinder in the shutoff valve 102 and the flow path switching circuit 103, and generates a voltage for operating the shutoff valve 102 and the cylinder.

[Structure of flow path switching valve]
FIG. 9 is a schematic view showing an example of the structure of the flow path switching valve 100 shown in FIG. In FIG. 9, detailed description of the parts common to the flow passage switching valve 100 in the first embodiment shown in FIGS. 4 and 5 will be omitted.

  As shown in FIG. 9, the flow path switching valve 100 includes the shutoff valves 101 and 102, the flow path switching circuit 103, the low pressure pipe 50, and the indoor unit side gas pipe 60 in the valve body 120 as in the first embodiment. And a high pressure gas pipe 80 is provided. The shutoff valves 101 and 102, the flow path switching circuit 103, the low pressure piping 50, the indoor unit side gas piping 60, and the high pressure gas piping 80 are made of a valve body 120 using a flame retardant material such as brass or aluminum. It is integrally formed with.

  Each of the shutoff valves 101 and 102 and the flow path switching circuit 103 is disposed to face the front. In this example, the shutoff valve 101 and the flow path switching circuit 103 are arranged on the bottom side of the valve body 120 so as to be aligned in the width direction, and the shutoff valve 102 is arranged on the top side of the valve body 120.

  Here, in this example, the coil for operating the valve of the shutoff valve 102 and the flow path switching valve coil 111 for operating the cylinder of the flow path switching circuit 103 are provided to the right, ie, in the same direction. . Thus, by arranging the shutoff valve 102 and the flow path switching circuit 103 so that the respective coils are positioned in the same direction, the accessibility to the coils can be improved.

  The indoor unit side gas piping 60 is formed, for example, to be orthogonal to the low pressure piping 50 and the high pressure gas piping 80 and to be horizontal to the bottom surface of the valve body 120. Thereby, the height of the flow path switching valve 100 can be suppressed. The indoor unit side gas piping 60 is not limited to this example, and may be formed, for example, to be perpendicular to the bottom surface of the valve body 120. Thereby, the length of the flow direction switching valve 100 in the width direction can be suppressed.

[Operation of flow path switching valve]
Next, operations in the various operation modes of the flow path switching valve 100 having the above configuration will be described. Here, the operation of the flow path switching valve 100 in the cooling operation mode, the heating operation mode, and the case where the heating operation mode is switched to the cooling operation mode will be described. FIG. 10 is a schematic view showing the state of each flow passage and cylinder in the flow passage switching valve 100 of FIG.

(In the cooling operation mode)
In the cooling operation mode, as in the first embodiment, first, the states of the flow paths and cylinders in the flow path switching valve 100 are set as shown in FIG. When the low pressure gas refrigerant flows from the indoor unit side gas pipe 60 into the flow path switching valve 100, the refrigerant is drawn from the bleed port 106a into the low pressure side suction flow path 104, and the shutoff valve 101 is in the "open" state. As a result, the refrigerant flowing from the indoor unit side gas pipe 60 passes through the shutoff valve 101 and flows out to the low pressure pipe 50.

  The refrigerant flowing from the indoor unit side gas pipe 60 also flows into the flow path 105 c and flows out to the low pressure pipe 50 via the flow path 105 c and the low pressure side suction flow path 104. Then, the refrigerant flowing out through the two paths merges in the low pressure pipe 50.

(In heating operation mode)
In the heating operation mode, first, the shutoff valve 102 is brought into the “open” state by the control of the flow path switching valve drive circuit 110. When the high-pressure gas refrigerant flows from the high-pressure gas pipe 80 into the flow path switching valve 100, it passes through the shut-off valve 102 in the "open" state and flows out from the indoor unit side gas pipe 60 via the flow path 105b.

(When switching from heating operation mode to cooling operation mode)
When the operation mode is switched from the heating operation mode to the cooling operation mode, first, the cylinder in the flow path switching circuit 103 is set as shown in FIG. When the cylinder is set in this manner, the indoor unit side gas pipe 60 and the low pressure side lead-in channel 104 are connected, and a path is formed where the indoor unit side gas pipe 60 and the low pressure pipe 50 are connected. Then, the refrigerant accumulated in the indoor unit side gas piping 60 flows out to the low pressure piping 50 via the low pressure side inlet channel 104. Thereby, the residual pressure of the indoor unit side gas piping 60 is reduced. Therefore, generation | occurrence | production of the flow noise by the refrigerant | coolant which stays in indoor unit side gas piping 60 which was mentioned above can be suppressed.

  As described above, in the flow path switching valve 100 according to the third embodiment, the same effect as that of the first embodiment can be obtained. Further, since the shutoff valve 102 is constituted by an electromagnetic valve as in the conventional flow path switching valve, the flow of this configuration is considered in consideration of the function and cost required of the branch unit 30 provided with the flow path switching valve 100. The road switching valve 100 can be selected.

  As mentioned above, although Embodiment 1-3 was described, this invention is not limited to Embodiment 1-3 mentioned above, A various deformation | transformation and application are possible within the range which does not deviate from the summary of this invention. .

  Reference Signs List 1 air conditioner, 2 buildings, 3 outdoor spaces, 4 indoor spaces, 5 spaces, 10 outdoor units, 11 compressors, 12 refrigerant flow switching devices, 13 heat source side heat exchangers, 14 accumulators, 15a, 15b, 15c, 15d check valve, 20, 20A, 20B indoor unit, 21, 21A, 21B throttling device, 22, 22A, 22B utilization side heat exchanger, 30 branching unit, 31 gas liquid separator, 32, 33 throttling device, 40 high pressure Piping, 50 low pressure piping, 60, 60a, 60b indoor unit side gas piping, 70 refrigerant piping, 80 high pressure gas piping, 90 control device, 100, 100A, 100B flow switching valve, 101, 102 shutoff valve, 103 flow switching Circuit, 104 low pressure side inlet channel, 105a, 105b, 105c channel, 106a, 106b bleed port, 1 10 flow path switching valve drive circuit, 111 flow path switching valve coil, 112, 113 anti-vibration spring, 120 valve body.

Claims (13)

A first shut-off valve provided between a gas pipe in which the refrigerant flows in and out and a low-pressure pipe in which the refrigerant flows out, and allowing or blocking the flow of the refrigerant;
A second shut-off valve provided between the gas pipe and a high pressure gas pipe into which the refrigerant flows, for permitting or blocking the flow of the refrigerant;
A flow path switching circuit that switches connection of a flow path between at least the gas pipe, the low pressure pipe, and the first shutoff valve, and the connected gas pipe, the low pressure pipe, and the first shutoff valve. When,
A drive circuit for driving the flow path switching circuit;
The drive circuit is
A flow path communicating with the first shutoff valve in the flow path switching circuit is connected with a flow path communicating with the low pressure pipe so that the refrigerant flowing into the first shutoff valve is drawn into the low pressure pipe. A flow path switching valve which causes the first shutoff valve to open. The flow path switching circuit is
Furthermore, it is connected to the second shutoff valve,
The drive circuit is
A flow path communicating with the second shutoff valve in the flow path switching circuit is connected with a flow path communicating with the low pressure pipe so that the refrigerant flowing into the second shutoff valve is drawn into the low pressure pipe. The flow path switching valve according to claim 1, wherein the second shutoff valve is opened by the valve. The second shutoff valve is a solenoid valve,
The flow path switching valve according to claim 1, wherein the drive circuit controls permission or shutoff of the refrigerant flowing through the second shutoff valve. The flow path switching circuit is
The flow path switching valve according to any one of claims 1 to 3, wherein the connection of the flow path communicating with the connected pipe is switched by the operation of a cylinder provided inside. A valve body in which each of the gas pipe, the low pressure pipe, and the high pressure gas pipe is connected, and the first shutoff valve, the second shutoff valve, the flow path switching circuit, and the drive circuit are accommodated. The flow path switching valve according to any one of claims 1 to 4, further comprising: The flow path switching valve according to claim 5, wherein the gas pipe is connected to the valve body so as to be parallel to a bottom surface of the valve body. The flow passage switching valve according to claim 5, wherein the gas pipe is connected to the valve body so as to be perpendicular to the bottom surface of the valve body. The flow according to any one of claims 5 to 7, wherein the first shut-off valve, the second shut-off valve, and the flow path switching circuit are arranged to face the front of the valve body. Road switching valve. The flow passage switching valve according to any one of claims 5 to 8, wherein the first shutoff valve, the second shutoff valve, and the flow passage switching circuit are integrally formed with the valve body. The gas pipe, the low pressure pipe, and the high pressure gas pipe are further provided.
The flow path switching valve according to claim 9, wherein the gas pipe, the low pressure pipe, and the high pressure gas pipe are further integrally formed with the valve body. 11. The flow passage switching valve according to claim 9, wherein each of the valve body and each portion integrally formed with the valve body is formed of brass or aluminum. The flow path switching valve according to any one of claims 1 to 11, wherein the drive circuit drives the flow path switching circuit by a direct current voltage. At least one outdoor unit generating cold or warm heat,
A plurality of indoor units performing air conditioning operation with cold energy or heat energy generated by the outdoor unit;
And a branching unit provided between the outdoor unit and the indoor unit for switching the flow of the refrigerant.
The branching unit is
The flow path switching valve according to any one of claims 1 to 11 is installed by the number corresponding to the number of the indoor units,
The gas pipe is connected to the indoor unit,
An air conditioner, wherein the low pressure piping is connected to the outdoor unit.

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