WO2018092186A1

WO2018092186A1 - Flow path switching valve and air conditioner using same

Info

Publication number: WO2018092186A1
Application number: PCT/JP2016/083802
Authority: WO
Inventors: 智一川越; 幸志東; 要平馬場
Original assignee: 三菱電機株式会社
Priority date: 2016-11-15
Filing date: 2016-11-15
Publication date: 2018-05-24
Also published as: JPWO2018092186A1; JP6605156B2

Abstract

This flow path switching valve comprises: a first shutoff valve which is provided between a gas pipe that allows a refrigerant to flow in and out and a low-pressure pipe that allows the refrigerant to flow out, and which permits or shuts off the flow of the refrigerant; a second shutoff valve which is provided between the gas pipe and a high-pressure gas pipe that allows the refrigerant to flow in, and which permits or shuts off the flow of the refrigerant; a flow path switching circuit which is connected to at least the gas pipe, the low-pressure pipe, and the first shutoff valve, and switches the connection of the flow paths among the connected gas pipe, low-pressure pipe, and first shutoff valve; and a drive circuit which drives the flow path switching circuit. The drive circuit opens the first shutoff valve by connecting the flow path communicating with the first shutoff valve and the flow path communicating with the low-pressure pipe in the flow path switching circuit so that the refrigerant flowing into the first shutoff valve is drawn into the low-pressure pipe.

Description

Flow path switching valve and air conditioner using the same

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

Conventionally, a flow path switching valve for switching the type of refrigerant supplied to an indoor unit is mainly used in a branch unit of a building multi-air conditioner. Such a flow path switching valve includes an electromagnetic shut-off valve, and can switch between a cooling flow path or a heating flow path by connecting an indoor unit side pipe, a high pressure gas pipe, and a low pressure pipe (for example, a 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 valve that shuts off the flow path from the high-pressure gas pipe side to the indoor unit side. And a shut-off valve. Actually, 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 cutoff valve that blocks the flow path. That is, the flow path switching valve includes three flow paths and three electromagnetic shut-off valves.

JP-A-5-322348

Incidentally, since the above-described flow path switching valve has three electromagnetic shut-off valves, it is necessary to install the shut-off valves at the front and rear. Also, considering the accessibility when exchanging the coil and valve for driving the shut-off valve, the flow path switching valve can be easily accessed to the shut-off valves installed both front and rear, It is necessary to arrange structures such as piping and sheet metal. For this reason, the housing size of the branch unit is increased, and it is difficult to reduce the size. Thereby, for example, when installing a branch unit on the ceiling of a building or the like, if the height of the ceiling behind is low, it becomes difficult to install the branch unit, and the area of the sheet metal that forms the outer shell increases, There is a problem that the cost increases.

In addition, such an electromagnetic shut-off valve generally uses an electromagnetic valve coil that is driven at a voltage of about 200 V. However, if an arc is generated in this electromagnetic valve coil, there is a risk of ignition. Therefore, it is necessary to form the outer structure of the branch unit using a material such as a sheet metal that is less likely to burn, and the drain pan or the surrounding exterior cannot be changed to a material such as foamed polystyrene having combustibility although it is inexpensive. . Thereby, dew condensation occurs due to increased airtightness, and there is a problem that the generation of drain water due to this dew condensation cannot be suppressed.

The present invention has been made in view of the above problems, and provides a flow path switching valve capable of improving the flexibility of installation and improving workability such as maintenance, and an air conditioner using the same. The purpose is to do.

The flow path switching valve according to the present invention is provided between a gas pipe through which refrigerant flows in and out and a low pressure pipe through which refrigerant flows out, and a first cutoff valve that allows or blocks the flow of the refrigerant, and the gas pipe And a high pressure gas pipe into which the refrigerant flows, and is connected to at least the gas pipe, the low pressure pipe, and the first cutoff valve, which allows or blocks the flow of the refrigerant. A drive circuit for switching the connection between the gas pipe, the low-pressure pipe and the first shut-off valve, and a drive circuit for driving the flow switch circuit; Connects the flow path communicating with the first shut-off valve in the flow path switching circuit and the flow path communicating with the low-pressure pipe so that the refrigerant flowing into the first shut-off valve is drawn into the low-pressure pipe. By making the first It is intended for opening the sectional 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, it is possible to improve the degree of freedom of installation and improve workability such as maintenance. .

It is the schematic which shows the example of installation of the air conditioner which concerns on Embodiment 1. FIG. It is the schematic which shows an example of the circuit structure of the air conditioner shown in FIG. 3 is a schematic diagram illustrating an example of a configuration of a flow path switching valve according to Embodiment 1. FIG. 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. 6 is a schematic diagram illustrating an example of a configuration of a flow path switching valve according to Embodiment 2. FIG. 6 is a schematic diagram illustrating an example of a configuration of a flow path switching valve according to Embodiment 3. FIG. 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 FIG.
Hereinafter, the air conditioner according to the first embodiment will be described. The air conditioner according to Embodiment 1 is a cooling / heating simultaneous type air conditioner in which a plurality of indoor units can simultaneously perform both cooling operation and heating operation.

[Example of air conditioner installation]
FIG. 1 is a schematic diagram illustrating an installation example of the air conditioner 1 according to the first embodiment. As shown in FIG. 1, the air conditioner 1 includes an outdoor unit 10 as a heat source unit, a plurality of

indoor units

20A and 20B, and a branch unit interposed between the outdoor unit 10 and the plurality of indoor units 20A and 20B. 30. The outdoor unit 10 and the branch unit 30 are connected by a high pressure pipe 40 and a low pressure pipe 50. Each of the branch unit 30 and the plurality of

indoor units

20A and 20B is connected by an indoor unit side gas pipe 60 and a refrigerant pipe 70. Thereby, a refrigerant circuit in which the refrigerant circulates in each pipe is formed.

In this example, two

indoor units

20A and 20B are connected to the branch unit 30. In the following description, when it is not necessary to particularly distinguish the

indoor units

20A and 20B, they are simply referred to as “indoor unit 20” as appropriate. Further, when referred to as “indoor unit 20”, it includes both one or a plurality.

The outdoor unit 10 is usually installed in a space outside the building 2 such as a building, for example, an outdoor space 3 such as a rooftop. 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 cooling or heating supplied from the outdoor unit 10 via the branch unit 30 to convert cooling air or heating air into a space inside the building 2, such as a living room or a server room. It supplies to a certain indoor space 4. In this example, the indoor unit 20 is installed in a space 5 such as the back of the ceiling, which is inside the building 2 but is different from the indoor space 4. Moreover, the indoor unit 20 can also be used, for example as floor heating which is installed under the floor and warms a floor surface with the heat supplied at the time of heating operation.

The branch unit 30 is configured as a housing different from the outdoor unit 10 and the indoor unit 20 so that it can be installed at a position different from the outdoor space 3 and the indoor space 4, for example, the space 5. The branch unit 30 is connected to the outdoor unit 10 by a high-pressure pipe 40 and a low-pressure pipe 50, and is connected to each of the plurality of indoor units 20 by an indoor unit-side gas pipe 60 and a refrigerant pipe 70. The branch unit 30 is for transmitting the cold or warm heat generated by the outdoor unit 10 to the indoor unit 20.

Note that the number of indoor units 20 connected to the branch unit 30 is not limited to this example. For example, one indoor unit 20 may be connected, or three or more indoor units 20 may be connected. . Further, for example, a plurality of outdoor units 10 may be provided, and one or a plurality of indoor units 20 may be connected to the plurality of outdoor units 10. That is, the number of outdoor units 10 and indoor units 20 can be appropriately determined according to the scale of the building 2 where the air conditioner 1 is installed.

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

In addition, CO ₂ (carbon dioxide), propane, isobutane, ammonia, etc., which are natural refrigerants, can be used as the refrigerant circulating in the refrigerant circuit, and the refrigerant depends on the use and purpose of the air conditioner 1. Can be used.

[Circuit configuration of air conditioner]
FIG. 2 is a schematic diagram illustrating an example of a circuit configuration of the air conditioner 1 illustrated in FIG. 1. In the example of FIG. 2, the case where the air conditioner 1 is configured by one outdoor unit 10, one branch unit 30, and two

indoor units

20A and 20B is shown. As described above, the number of outdoor units 10 and indoor units 20 is 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 a low-temperature and low-pressure refrigerant, compresses the refrigerant, and discharges it in a high-temperature and high-pressure state. As the compressor 11, for example, an inverter compressor or the like that can control the capacity that is the refrigerant delivery amount per unit time by arbitrarily changing the drive frequency can be used.

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

The heat source side heat exchanger 13 performs heat exchange between air (hereinafter referred to as “outdoor air” as appropriate) supplied by a blower such as a fan (not shown) and the refrigerant. 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 that is the suction side of the compressor 11. The accumulator 14 stores surplus refrigerant generated due to a difference in operating state between the cooling operation and the heating operation, surplus refrigerant with respect to a transient change in operation, and the like.

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

The check valve 15 c is provided in the second connection pipe 31 b that connects the high pressure pipe 40 and the low pressure pipe 50, and causes the refrigerant discharged from the compressor 11 to flow through the branch unit 30 during the heating operation. The check valve 15d is provided in the high-pressure pipe 40 between the heat source side heat exchanger 13 and the branch unit 30, and causes the refrigerant to flow 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 perform, for example, cooling and heating of air in an air-conditioning target space. The indoor unit 20A is composed of an expansion device 21A and a use side heat exchanger 22A. The indoor unit 20B is composed of an expansion device 21B and a use side heat exchanger 22B.

In the following description, when it is not necessary to distinguish between the

diaphragm devices

21A and 21B, they will be simply referred to as “the diaphragm device 21” as appropriate. Similarly, the use

side heat exchangers

22A and 22B are simply referred to as “use side heat exchanger 22” as appropriate. When referred to as “the expansion device 21” or “the use-side heat exchanger 22”, each includes both one or a plurality.

The expansion device 21 decompresses and expands the refrigerant by adjusting the flow rate of the refrigerant. The expansion device 21 is constituted by a valve capable of controlling the opening, such as an electronic expansion valve. The diaphragm device 21 is not limited to this, and other diaphragm devices such as capillaries can also be used.

The use side heat exchanger 22 performs heat exchange between air and a refrigerant supplied by a blower such as a fan (not shown). Thereby, heating air or cooling air supplied to the indoor space 4 is generated. Specifically, the use-side heat exchanger 22 functions as an evaporator when the refrigerant carries cold heat during the cooling operation, and cools the air in the indoor space 4 that is the air-conditioning target space by cooling the air. Do. In addition, the use side heat exchanger 22 functions as a condenser when the refrigerant is transporting warm heat during the heating operation, and heats the air in the indoor space 4 to perform heating.

(Branch unit)
The branch unit 30 has a function of supplying the cold or hot heat supplied from the outdoor unit 10 to the indoor unit 20. The branch unit 30 includes a gas-liquid separator 31, flow path switching valves 100 A and 100 B, and

throttle devices

32 and 33. The number of flow path switching valves 100 A and 100 B corresponding to the number of indoor units 20 connected to the branch unit 30 is provided.

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 path using the flow

path switching valves

100A and 100B, each of the

indoor units

20A and 20B connected to the branch unit 30 can simultaneously perform the cooling operation and the heating operation. The flow

path switching valves

100A and 100B are composed of, for example, three-way valves. Details of the flow

path switching valves

100A and 100B will be described later. In the following description, when it is not necessary to particularly distinguish the flow

path switching valves

100A and 100B, the flow path switching valve 100 will be appropriately referred to as “flow path switching valve 100”.

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. In addition, one of the flow path switching valves 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 opening and closing of the flow

path switching valves

100A and 100B is controlled by the control device 90.

The gas-liquid separator 31 is connected to the high-pressure pipe 40 and to each of the inflow / outflow sides of the indoor unit 20. The gas-liquid separator 31 has a function of separating the flowing 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 expands the refrigerant by decompressing it. The expansion device 33 is provided in a connection pipe that connects the low-pressure pipe 50 and the piping between the expansion device 32 and the expansion device 21A of the indoor unit 20A and the expansion device 21B of the indoor unit 20B. Inflate. The throttling device 32 and the throttling device 33 are configured by, for example, valves capable of controlling the opening degree, such as capillaries or electronic expansion valves. When the expansion device 32 and the expansion device 33 are expansion valves, the valve opening degree is controlled by the control device 90.

(Control device)
The air conditioner 1 is provided with a control device 90. The control device 90 includes, for example, software executed on an arithmetic device such as a microcomputer or a CPU (Central Processing Unit), hardware such as a circuit device that realizes various functions, and the like. To 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 100 A and 100 B, and the like based on the operation content instructed by the user.

[Configuration of flow path switching valve]
FIG. 3 is a schematic diagram illustrating 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 shut-off

valves

101 and 102, a flow path switching circuit 103, and a flow path switching valve drive circuit 110. In the first embodiment, the flow path switching valve 100 is formed with the low-pressure pipe 50 and the high-pressure gas pipe 80 included in the constituent elements.

The shutoff valve 101 is provided between the flow path 105 a branched from the indoor unit side gas pipe 60 and the low pressure pipe 50. The shutoff valve 101 is connected to a bleed port 106a as a refrigerant intake pipe. The shut-off valve 101 opens or closes according to the pressure difference between the pressure on the flow path 105a side and the pressure on the low pressure pipe 50 side, thereby permitting or blocking the refrigerant flow between the flow path 105a and the low pressure pipe 50. For example, the shutoff valve 101 enters a “closed” state when the refrigerant is drawn into the bleed port 106a and the above-described differential pressure decreases, and enters an “open” state when the differential pressure increases.

The shutoff valve 102 is provided between the flow path 105 b branched from the indoor unit side gas pipe 60 and the high pressure gas pipe 80. A bleed port 106b is connected to the shutoff valve 102 as a refrigerant intake pipe. The shutoff valve 102 opens or closes according to the pressure difference between the pressure on the flow path 105b side and the pressure on the high pressure gas pipe 80 side, thereby permitting or shutting off the refrigerant flow between the flow path 105b and the high pressure gas pipe 80. To do. For example, the shutoff valve 102 enters the “closed” state when the refrigerant is drawn into the bleed port 106b and the above-described differential pressure decreases, and enters the “open” state when the differential pressure increases.

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, a high-pressure gas refrigerant flows out from the flow path switching valve 100 to the indoor unit 20 through the indoor unit side gas pipe 60.

The downstream side of the low-pressure pipe 50 is connected to the outdoor unit 10, and the gas refrigerant or the two-phase refrigerant flows out from the flow path switching valve 100 to the outdoor unit 10 through the low-pressure pipe 50. The upstream side of the high-pressure gas pipe 80 is connected to the gas-liquid separator 31, and 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 low-pressure side lead-in flow path 104, the flow path 105c, and the

bleed ports

106a and 106b connected to the low-pressure pipe 50 are connected to the flow path switching circuit 103. The flow path switching circuit 103 is provided with a cylinder having a hollow inside 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 the cylinder in the flow path switching circuit 103, and generates a voltage for operating the cylinder. The voltage output method in the flow path switching valve drive circuit 110 is not limited, but in this example, the flow path switching valve drive circuit 110 outputs a voltage of about DC 20 V, for example, which does not cause a fire. For example, when it is not necessary to consider ignition, the flow path switching valve drive circuit 110 may output a voltage of about AC 200 V, for example.

[Structure of flow path switching valve]
FIG. 4 is a schematic diagram showing an example of the structure of the flow path switching valve 100 shown in FIG. In the following, the vertical direction when FIG. 4 is viewed 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”. To do. Moreover, in the following drawings, including FIG. 4, the relationship of the size of each component may be different from the actual one.

As shown in FIG. 4, in the flow path switching valve 100,

shutoff valves

101 and 102, a flow path switching circuit 103, and a flow path switching valve drive circuit 110 are accommodated in a valve body 120 that forms an outer shell. Further, the low-pressure pipe 50, the indoor unit side gas pipe 60, and the 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 pipe 50, the indoor unit side gas pipe 60, and the high pressure gas pipe 80 are made of a valve body 120 using a flame-retardant material such as brass or aluminum. And is formed integrally.

Each of the shut-off

valves

101 and 102 and the flow path switching circuit 103 are arranged so as to face the front. In this example, the shut-off valve 101 and the flow path switching circuit 103 are arranged on the bottom side of the valve main body 120 so as to be aligned in the width direction, and the shut-off valve 102 is arranged on the upper side of the valve main body 120.

The low-pressure pipe 50 and the high-pressure gas pipe 80 are formed in the depth direction so as to be parallel to each other, for example. Further, the indoor unit side gas pipe 60 is formed, for example, so as to be orthogonal to the low pressure pipe 50 and the high pressure gas pipe 80 and to be horizontal with the bottom surface of the valve body 120. Thus, by forming the indoor unit side gas pipe 60 so as to be horizontal with the bottom surface of the valve 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.

The anti-vibration springs 112 and 113 are provided in the shut-off

valves

101 and 102, respectively. Generally, in the shut-off

valves

101 and 102, when the circulation of the circulating refrigerant is small, the self-excited vibration operation of the valve may occur. Since the self-excited vibration operation of the valve generates a so-called “flickering sound”, for example, when the branch unit 30 is installed in a space such as the ceiling of a living room, there is a possibility that the resident may feel uncomfortable. Therefore, in the first embodiment,

vibration preventing springs

112 and 113 are provided in order to prevent the self-excited vibration operation of the valve that occurs when the flow rate of the refrigerant flowing through the

shutoff valves

101 and 102 is small. It has been.

Note that when the self-excited vibration operation of such a valve is not a problem or when the flow path switching valve 100 is not used in a region where the self-excited vibration operation occurs, the

vibration preventing springs

112 and 113 need not be used. 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 that of the flow path switching valve 100 shown in FIG. Other portions 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 perpendicular to the bottom surface of the valve body 120, for example. Thus, by forming the indoor unit side gas pipe 60 so as to be perpendicular to the bottom surface of the valve main body 120, the length of the flow path switching valve 100 in the width direction can be suppressed.

[Air conditioner operation]
Next, the operation | movement of the refrigerant | coolant in the various operation modes in the air conditioner 1 which has the said structure is demonstrated. As the operation mode in the air conditioner 1 according to Embodiment 1, the

indoor unit

20A and 20B are both in the cooling operation mode in which the cooling operation is performed, the heating operation mode in which the heating operation is performed, and the

indoor units

20A and 20B. However, there are a cooling main operation mode and a heating main operation mode in which both the cooling operation and the heating operation are performed at the same time, and either one of the operations is mainly performed.

(Cooling mode only)
First, the operation of the refrigerant in the cooling only operation mode will be described. In the all-cooling operation mode, both the

indoor units

20A and 20B 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. The low-temperature and low-pressure refrigerant is compressed by the compressor 11 and discharged as a high-temperature and 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 that has flowed into the heat source side heat exchanger 13 condenses while exchanging heat with the outdoor air and dissipates heat, and flows out of the heat source side heat exchanger 13 as a high-pressure liquid refrigerant.

The high-pressure liquid refrigerant that has flowed 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 that has flowed into the branch unit 30 flows out of the branch unit 30 via the gas-liquid separator 31 and the expansion device 32, and flows into the

indoor units

20A and 20B.

The high-pressure liquid refrigerant that has flowed 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 that has flowed into the use-side heat exchanger 22A exchanges heat with the room air to absorb heat and evaporate, thereby cooling the room air and becoming a low-pressure gas refrigerant. It flows out of the exchanger 22A.

Also, the high-pressure liquid refrigerant that has flowed 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 that has flowed into the use side heat exchanger 22B exchanges heat with the room air to absorb heat and evaporate, thereby cooling the room air and becoming a low pressure gas refrigerant. It flows out of the exchanger 22B.

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

The low-pressure gas refrigerant flowing into the outdoor unit 10 passes through the check valve 15a, the refrigerant flow switching device 12, and the accumulator 14, and is sucked into the compressor 11. Thereafter, 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 all heating operation mode, both the

indoor units

20A and 20B perform the heating operation.

In the heating only operation mode, the refrigerant flow switching device 12 in the outdoor unit 10 is switched to the state indicated by the dotted line in FIG. The low-temperature and low-pressure refrigerant is compressed by the compressor 11 and discharged as a high-temperature and 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 that has flowed into the branch unit 30 flows out of the branch unit 30 via 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 and high-pressure gas refrigerant that has flowed into the indoor unit 20A flows into the use-side heat exchanger 22A, heats the indoor air and condenses while dissipating heat, thereby heating the indoor air to become a high-pressure liquid refrigerant. It flows out of the use side heat exchanger 22A. The high-pressure liquid refrigerant that has flowed out of the use-side heat exchanger 22A is decompressed and expanded by the expansion device 21A, becomes a low-pressure gas-liquid two-phase refrigerant or liquid refrigerant, and flows out of the indoor unit 20A.

The high-temperature and high-pressure gas refrigerant that has flowed into the indoor unit 20B flows into the use-side heat exchanger 22B, heats the indoor air and condenses while dissipating heat, thereby heating the indoor air, And flows out from the use side heat exchanger 22B. The high-pressure liquid refrigerant that has flowed out of the use-side heat exchanger 22B is decompressed and expanded by the expansion device 21B, becomes a low-pressure gas-liquid two-phase refrigerant or liquid refrigerant, and flows out of the indoor unit 20B.

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

The low-temperature and low-pressure gas refrigerant flowing out from 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. Thereafter, the above-described circulation is repeated.

(Cooling 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. The low-temperature and low-pressure refrigerant is compressed by the compressor 11 and discharged as a high-temperature and 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 that has flowed into the heat source side heat exchanger 13 condenses while exchanging heat with outdoor air and dissipates heat, and then flows out of the heat source side heat exchanger 13 as a high-pressure gas-liquid two-phase refrigerant.

The high-pressure gas-liquid two-phase refrigerant that has flowed out of the heat source side heat exchanger 13 flows out of the outdoor unit 10 through the check valve 15 d and flows into the branch unit 30. The high-pressure gas-liquid two-phase refrigerant that has flowed 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 from 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, heats the indoor air and condenses while dissipating heat, thereby heating the indoor air and using it as a high-pressure liquid refrigerant. It flows out from the side heat exchanger 22B. The high-pressure liquid refrigerant that has flowed out of the use-side heat exchanger 22B is decompressed and expanded by the expansion device 21B, becomes an intermediate-pressure gas-liquid two-phase refrigerant or liquid refrigerant, and flows out of the indoor unit 20B.

On the other hand, the high-pressure liquid refrigerant separated by the gas-liquid separator 31 and the intermediate-pressure gas-liquid two-phase refrigerant or liquid refrigerant 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 intermediate-pressure gas-liquid two-phase refrigerant or liquid refrigerant flowing out of the indoor unit 20B are depressurized 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 that has flowed into the use-side heat exchanger 22A exchanges heat with the room air to absorb heat and evaporate, thereby cooling the room air and becoming a low-pressure gas refrigerant. It flows out of the exchanger 22A. The low-pressure gas refrigerant that has flowed 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.

(Heating main operation mode)
Next, the operation of the refrigerant in the heating 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, as in the cooling main operation mode.

In the heating main operation mode, the refrigerant flow switching device 12 in the outdoor unit 10 is switched to the state indicated by the dotted line in FIG. The low-temperature and low-pressure refrigerant is compressed by the compressor 11 and discharged as a high-temperature and 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 that has flowed 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 that has flowed out of the branch unit 30 flows into the indoor unit 20B. The high-temperature and high-pressure gas refrigerant that has flowed into the indoor unit 20B flows into the use-side heat exchanger 22B, heats the indoor air and condenses while dissipating heat, thereby heating the indoor air to become a high-pressure liquid refrigerant. It flows out from the use side heat exchanger 22B. The high-pressure liquid refrigerant that has flowed out of the use-side heat exchanger 22B is decompressed and expanded by the expansion device 21B, becomes an intermediate-pressure gas-liquid two-phase refrigerant or liquid refrigerant, and flows out of the indoor unit 20B.

The intermediate-pressure gas-liquid two-phase refrigerant or liquid refrigerant that has flowed out of the indoor unit 20B flows into the indoor unit 20A. The intermediate-pressure gas-liquid two-phase refrigerant or liquid refrigerant that has flowed 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 refrigerant flowing into the outdoor unit 10 flows into the heat source side heat exchanger 13 via the check valve 15b. The low-pressure gas refrigerant that has flowed into the heat source side heat exchanger 13 exchanges heat with outdoor air, absorbs heat and evaporates, and becomes a low-temperature and low-pressure gas refrigerant that flows out of the heat source side heat exchanger 13.

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

(In cooling operation mode)
In the cooling operation mode, first, the state of each flow path and cylinder in the flow path switching valve 100 is set as shown in FIG. When a 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 intake flow path 104, and the shut-off 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.

Further, the refrigerant that has flowed in from the indoor unit side gas pipe 60 also flows into the flow path 105c, and flows out to the low pressure pipe 50 via the flow path 105c and the low pressure side intake flow path 104. Then, the refrigerant that has flowed out through the two paths merges in the low-pressure pipe 50.

(In heating mode)
In the heating operation mode, first, the state of each flow path and cylinder in the flow path switching valve 100 is set as shown in FIG. When a 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 intake flow path 104, and the shutoff valve 102 is in the “open” state. Thereby, the refrigerant flowing in 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 remains in the indoor unit side gas pipe 60 without being discharged, 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 pipe 60 and the pressure of the low pressure pipe 50 is large. Therefore, when the operation mode is switched and the shut-off valve 101 is in the “open” state, a large flow noise of the gas refrigerant due to the pressure difference may occur. Such a flowing sound 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 in the indoor unit side gas pipe 60 is reduced using the flow path 105c.

In this case, specifically, the cylinder in the flow path switching circuit 103 is first set as shown in FIG. When the cylinder is set in this way, the indoor unit side gas pipe 60 and the low pressure side intake passage 104 are connected, and a path is formed in which the indoor unit side gas pipe 60 and the low pressure pipe 50 are connected. Then, the refrigerant staying in the indoor unit side gas pipe 60 flows out to the low pressure pipe 50 via the low pressure side intake passage 104. Thereby, the residual pressure of the indoor unit side gas pipe 60 is reduced. Therefore, it is possible to suppress the generation of flow noise due to the refrigerant that stays in the indoor unit side gas pipe 60 as described above.

It should be noted that the present invention is not limited to the above-described method, and it is conceivable to suppress the generation of a flow noise caused by the refrigerant staying in the indoor unit side gas pipe 60 using, for example, the shutoff valve 101. However, when the flow path diameter is large like the shut-off valve 101, the above-described gas flow noise is generated when the control for removing the refrigerant staying in the indoor unit side gas pipe 60 is performed. In order to suppress the generation of gas flow noise, a valve that allows a low flow rate refrigerant to flow out is required. Therefore, it is not appropriate to use the shut-off valve 101 in this way.

As described above, the flow path switching valve 100 according to the first embodiment is provided between the indoor unit side gas pipe 60 through which the refrigerant flows in and out and the low pressure pipe 50 through which the refrigerant flows out, and allows the refrigerant to flow. Alternatively, the shut-off valve 101 that shuts off, the shut-off valve 102 that is provided between the indoor unit side gas pipe 60 and the high-pressure gas pipe 80 into which the refrigerant flows and allows or shuts off the refrigerant flow, and at least the indoor unit side gas pipe 60. A flow path switching circuit 103 that is connected to the low-pressure pipe 50 and the shut-off valve 101 and switches the connection between the connected indoor unit side gas pipe 60, the low-pressure pipe 50, and the shut-off valve 101; A flow path switching valve drive circuit 110 for driving the flow path 103, and the flow path switching valve drive circuit 110 is configured to draw the refrigerant flowing into the shutoff valve 101 into the low pressure pipe 50. By connecting the flow path communicating with the passage and the low pressure piping 50 communicating with the shut-off valve 101 in the circuit 103, to open the shut-off valve 101.

Thus, in the first embodiment, the flow path switching circuit 103 is driven to control the opening / closing of the shutoff valve 101. Since the voltage required to drive the flow path switching circuit 103 may be lower than the voltage required to drive the solenoid valve, for example, ignition due to the occurrence of an arc can be suppressed.

Moreover, by suppressing ignition, the drain pan or the exterior provided in the branch unit 30 including the flow path switching valve 100 can be changed to an inexpensive material such as styrene foam having combustibility.

Further, in the flow path switching valve 100 according to the first embodiment, the indoor unit side gas pipe 60 is formed to be parallel to the bottom surface of the valve 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 Embodiment 1, the indoor unit side gas pipe 60 is formed to be perpendicular to the bottom surface of the valve body 120. Thereby, the length of the width direction of the flow-path switching valve 100 can be suppressed, and the freedom degree of installation of the branch unit 30 provided with this 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 so as to face the front surface of the valve main body 120. Thereby, the accessibility to the valve and the coil for driving the valve by the operator is improved, and work such as maintenance can be easily performed.

Embodiment 2. FIG.
Next, an air conditioner according to Embodiment 2 will be described. The air conditioner according to the second embodiment is different from the first embodiment in the configuration of the flow path switching valve 100. In the following description, portions common to the above-described first embodiment are denoted by the same reference numerals and description thereof is omitted.

Since the air conditioner 1 according to the second embodiment has the configuration shown in FIGS. 1 and 2 as in the first embodiment, the description thereof is omitted here.

[Configuration of flow path switching valve]
FIG. 7 is a schematic diagram illustrating 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 shut-off

valves

101 and 102, a flow path switching circuit 103, and a flow path switching valve drive circuit 110. Note that the flow path switching valve 100 differs from the flow path switching valve 100 according to Embodiment 1 in that the low pressure pipe 50 and the high pressure gas pipe 80 are excluded from the constituent elements. Thereby, the material used for the flow path switching valves 100 such as brass or aluminum can be reduced.

As described above, the second embodiment can provide the same effects as the first embodiment. Further, the low pressure pipe 50 and the high pressure gas pipe 80 formed in the flow path switching valve 100 can be removed from the constituent elements, and the material used for the flow path switching valve 100 can be reduced, so that the cost can be suppressed.

Embodiment 3 FIG.
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 an electromagnetic valve. In the following description, parts common to those in the first and second embodiments described above are denoted by the same reference numerals and description thereof is omitted.

Since the air conditioner 1 according to the third embodiment has the configuration shown in FIGS. 1 and 2 as in the first embodiment, the description thereof is omitted here.

[Configuration of flow path switching valve]
FIG. 8 is a schematic diagram illustrating 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 shut-off

valves

101 and 102, a flow path switching circuit 103, and a flow path switching valve drive circuit 110.

The shut-off valve 101 is provided between the flow path 105a and the low-pressure pipe 50, and the bleed port 106a is connected, as in the first embodiment. The shut-off valve 101 opens or closes according to the pressure difference between the pressure on the flow path 105a side and the pressure on the low pressure pipe 50 side, thereby permitting or blocking the refrigerant flow between the flow path 105a and the low pressure pipe 50. For example, the shutoff valve 101 enters a “closed” state when the refrigerant is drawn into the bleed port 106a and the above-described differential pressure decreases, and enters an “open” state when the differential pressure increases.

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

The flow path switching circuit 103 is connected to a low-pressure side intake flow path 104, a flow path 105c, and a bleed port 106a. The flow path switching circuit 103 is provided with a cylinder 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 the cylinders in the cutoff valve 102 and the flow path switching circuit 103, and generates a voltage for operating the cutoff valve 102 and the cylinder.

[Structure of flow path switching valve]
FIG. 9 is a schematic diagram showing an example of the structure of the flow path switching valve 100 shown in FIG. In FIG. 9, detailed description of portions common to the flow path switching valve 100 in Embodiment 1 shown in FIGS. 4 and 5 is omitted.

As shown in FIG. 9, the flow path switching valve 100 includes a

shutoff valve

101 and 102, a flow path switching circuit 103, a low pressure pipe 50, an indoor unit side gas pipe 60, as in the first embodiment. In addition, a high-pressure gas pipe 80 is provided. The

shutoff valves

Each of the shut-off

valves

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 in the right direction, that is, in the same direction. . Thus, the accessibility to the coil can be improved by arranging the shutoff valve 102 and the flow path switching circuit 103 so that the coils are positioned in the same direction.

The indoor unit side gas pipe 60 is formed, for example, so as to be orthogonal to the low pressure pipe 50 and the high pressure gas pipe 80 and to be horizontal with the bottom surface of the valve body 120. Thereby, the height of the flow path switching valve 100 can be suppressed. In addition, the indoor unit side gas piping 60 is not restricted to this example, For example, you may form so that it may become perpendicular | vertical with the bottom face of the valve main body 120. FIG. Thereby, the length of the width direction of the flow path switching valve 100 can be suppressed.

[Operation of flow path switching valve]
Next, the operation | movement at the time of various operation modes in the flow-path switching valve 100 which has the said structure is demonstrated. Here, the operation of the flow path switching valve 100 in the cooling operation mode, in the heating operation mode, and when the heating operation mode is switched to the cooling operation mode will be described. FIG. 10 is a schematic diagram showing the state of each flow path and cylinder in the flow path switching valve 100 of FIG.

(In cooling operation mode)
In the cooling operation mode, as in the first embodiment, first, the state of each flow path and cylinder in the flow path switching valve 100 is set as shown in FIG. When a 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 intake flow path 104, and the shut-off 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.

(In heating mode)
In the heating operation mode, first, the shutoff valve 102 is set to the “open” state under the control of the flow path switching valve drive circuit 110. When high-pressure gas refrigerant flows from the high-pressure gas pipe 80 into the flow path switching valve 100, the high-pressure gas refrigerant passes through the shut-off valve 102 in the “open” state and flows out from the indoor unit side gas pipe 60 through 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 way, the indoor unit side gas pipe 60 and the low pressure side intake passage 104 are connected, and a path is formed in which the indoor unit side gas pipe 60 and the low pressure pipe 50 are connected. Then, the refrigerant staying in the indoor unit side gas pipe 60 flows out to the low pressure pipe 50 via the low pressure side intake passage 104. Thereby, the residual pressure of the indoor unit side gas pipe 60 is reduced. Therefore, it is possible to suppress the generation of flow noise due to the refrigerant that stays in the indoor unit side gas pipe 60 as described above.

As described above, the flow path switching valve 100 according to the third embodiment can achieve the same effects as those of the first embodiment. Further, since the shutoff valve 102 is configured by an electromagnetic valve in the same manner as a conventional flow path switching valve, the flow and flow of this configuration are considered in consideration of the function and cost required of the branch unit 30 provided with the flow path switching valve 100. The path switching valve 100 can be selected.

While the first to third embodiments have been described above, the present invention is not limited to the first to third embodiments described above, and various modifications and applications can be made without departing from the scope of the present invention. .

1 air conditioner, 2 building, 3 outdoor space, 4 indoor space, 5 space, 10 outdoor unit, 11 compressor, 12 refrigerant flow switching device, 13 heat source side heat exchanger, 14 accumulator, 15a, 15b, 15c, 15d check valve, 20, 20A, 20B indoor unit, 21, 21A, 21B throttle device, 22, 22A, 22B use side heat exchanger, 30 branch unit, 31 gas-liquid separator, 32, 33 throttle 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 path switching valve, 101, 102 Shutoff valve, 103 Flow path switching Circuit, 104 Low-pressure side lead-in channel, 105a, 105b, 105c Channel, 106a, 106 Bleed port, 110 channel switching valve driving circuit, 111 the channel switching valve coils, 112 and 113 antivibration spring, 120 valve body.

Claims

A first shut-off valve provided between a gas pipe into which the refrigerant flows in and out and a low pressure pipe from which the refrigerant flows out, and allows or blocks the flow of the refrigerant;
A second shut-off valve provided between the gas pipe and the high-pressure gas pipe into which the refrigerant flows, and allows or blocks the flow of the refrigerant;
A flow path switching circuit that is connected to at least the gas pipe, the low pressure pipe, and the first shut-off valve, and switches connection of the flow path between the connected gas pipe, the low-pressure pipe, and the first shut-off valve. When,
A drive circuit for driving the flow path switching circuit,
The drive circuit is
The flow path communicating with the first shut-off valve in the flow path switching circuit and the flow path communicating with the low-pressure pipe are connected so that the refrigerant flowing into the first shut-off valve is drawn into the low-pressure pipe. A flow path switching valve for opening the first shut-off valve.
The flow path switching circuit is
And is connected to the second shut-off valve,
The drive circuit is
The flow path communicating with the second shut-off valve in the flow path switching circuit and the flow path communicating with the low-pressure pipe are connected so that the refrigerant flowing into the second shut-off valve is drawn into the low-pressure pipe. The flow path switching valve according to claim 1, wherein the second shut-off valve is opened.
The second shut-off valve is a solenoid valve;
2. The flow path switching valve according to claim 1, wherein the drive circuit controls the allowance or blockage 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 connection of a flow path communicating with a connected pipe is switched by an 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 shut-off valve, the second shut-off 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 that the gas pipe is parallel to the bottom surface of the valve body.
The flow path switching valve according to claim 5, wherein the gas pipe is connected to the valve body so that the gas pipe is 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 so as to face a front surface of the valve body. Road switching valve.
The flow path switching valve according to any one of claims 5 to 8, wherein the first cutoff valve, the second cutoff valve, and the flow path switching circuit are formed integrally with the valve body.
The gas pipe, the low-pressure pipe, and the high-pressure gas pipe,
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 formed integrally with the valve body.
The flow path switching valve according to claim 9 or 10, wherein each of the valve body and each part formed integrally 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 with a DC voltage.
At least one outdoor unit that generates cold or warm heat;
A plurality of indoor units that perform air-conditioning operation with cold or hot heat generated by the outdoor unit;
A branch unit that is provided between the outdoor unit and the indoor unit, and switches a refrigerant flow;
The branch unit is
The flow path switching valve according to any one of claims 1 to 11 is installed in a number corresponding to the number of the indoor units,
The gas pipe is connected to the indoor unit;
An air conditioner in which the low-pressure pipe is connected to the outdoor unit.