WO2018012036A1

WO2018012036A1 - Refrigerant flow passage switching unit and air conditioner provided with same

Info

Publication number: WO2018012036A1
Application number: PCT/JP2017/010941
Authority: WO
Inventors: 一紀福田; 内藤　宏治; 一浩土橋
Original assignee: 日立ジョンソンコントロールズ空調株式会社
Priority date: 2016-07-11
Filing date: 2017-03-17
Publication date: 2018-01-18
Also published as: JP2018009707A

Abstract

The present invention is provided with: a high-pressure header 15 and a gas pipe 11a that are connected to the discharge side of a compressor included in an outdoor unit 2; a high-pressure valve 9 that controls, by opening and closing, the flow of a refrigerant passing through the high-pressure header 15 and the gas pipe 11a; a low-pressure header 6 and a gas pipe 11b that branch from the gas pipe 11a and that are connected to the suction side of a compressor included in an outdoor unit 3; a low-pressure valve 10 that controls, by opening and closing, the flow of the refrigerant passing through the low-pressure header 6 and the gas pipe 11b and that is provided at the same position in the height direction as the high-pressure valve 9; and a gas pipe 11c that further branches from the above branch to be connected to a heat exchanger included in the outdoor unit 3 and that has a part extending downward in a direction toward the heat exchanger.

Description

Refrigerant flow path switching unit and air conditioner provided with the same

The present invention relates to a refrigerant flow switching unit and an air conditioner provided with the same, and more particularly, to a refrigerant flow switching unit capable of suppressing the height dimension and suppressing the accumulation of refrigerant therein, and an air conditioner provided with the same. About.

There is known a so-called multi-type air conditioner in which indoor units are provided in each room, and cooling and heating can be operated independently and simultaneously in each indoor unit. Such air conditioners are used, for example, in buildings and commercial facilities. In the multi-type air conditioner, the flow direction of the refrigerant is controlled for each indoor unit, so that the cooling and heating in each indoor unit can be changed.

In the multi-type air conditioner, a refrigerant flow switching unit is provided between the outdoor unit and the plurality of indoor units to switch the flow direction of the refrigerant to the respective indoor units. In this refrigerant flow path switching unit, a collective type in which a plurality of indoor units are connected to one refrigerant flow path switching unit, and (one or more in total) refrigerant flow path switching for each indoor unit Two types are known, of which individual units are provided. Among these, the high-pressure gas pipe and the low-pressure gas pipe connected to the outdoor unit, and the gas pipes connected to the respective indoor units are connected to the former collective type refrigerant channel switching unit. A high pressure valve is provided in the middle of the high pressure gas pipe, and a low pressure valve is provided in the middle of the low pressure gas pipe, and opening and closing of these valves are controlled to allow refrigerant flow in the indoor units. The direction is controllable.

In the air conditioner, a structure in which the refrigerant does not easily stagnate is adopted so that the so-called "refrigerant stagnation" which is a phenomenon of accumulation of the refrigerant does not occur at the time of thermo-off or indoor shutdown of the indoor unit. Thereby, refrigerant stagnation is prevented and stable operation is possible. Therefore, it is preferable that the refrigerant flow switching unit also have a structure in which the refrigerant does not easily stagnate.

The technology described in Patent Document 1 is related to the technology for preventing the stagnation of the refrigerant in the flow path switching unit. Patent Document 1 discloses a refrigerant flow switching unit which is disposed between a heat source unit forming a refrigerant circuit and a utilization unit to switch the flow of the refrigerant, and is connected to a suction gas communication pipe extending from the heat source unit. First refrigerant pipe, a second refrigerant pipe connected to a high and low pressure gas communication pipe extending from the heat source unit, a third refrigerant pipe connected to a gas pipe extending to the utilization unit, and the first refrigerant pipe It is connected to the 2nd refrigerant piping and the 3rd refrigerant piping, and it distributes to the connection part which connects the 1st refrigerant piping, the 2nd refrigerant piping, and the 3rd refrigerant piping, and the 1st refrigerant piping. And a second switching valve disposed in the second refrigerant pipe, wherein the second switching valve is disposed at a position higher than the first switching valve, The third refrigerant pipe is located at the lowest position It has a bottom, wherein connected to said connecting portion at the bottom, the refrigerant flow path switching unit is described.

JP, 2015-114049, A

A cold refrigerant flows through piping etc. which comprise a refrigerant | coolant flow-path switching unit. Therefore, in order to prevent condensation on the surface of the pipe or the like, a heat insulating material is often disposed around the pipe or the like. However, the connection structure such as piping is complicated. Then, for example, the piping etc. which comprise a refrigerant | coolant flow-path switching unit are accommodated in a housing | casing, and the whole inside of piping etc. is thermally insulated by filling the inside of the said housing with the foaming agent as a heat insulating material and solidifying. It will be.

Here, in the refrigerant channel switching unit described in Patent Document 1, the position of the second motor-operated valve Ev2 (high-pressure valve) provided on the high-pressure-side first header 55 side is the low-pressure-side second header 56 or the like. It is higher than the position of the first motor operated valve Ev1 (low pressure valve) provided on the side of the third header 57 (see particularly FIG. 6). Then, when the position of the second motor-operated valve Ev2 is higher than the position of the first motor-operated valve Ev1, as in the technique described in Patent Document 1, the dimension in the height direction of the refrigerant channel switching unit becomes large. . Along with this, the dimension in the height direction of the casing for accommodating the piping and the like that constitutes the refrigerant flow path switching unit also becomes large.

And if the dimension of the height direction of a case becomes large, the volume of the space filled with a foaming agent will become large. In this case, the amount of the foaming agent filled in the inside of the casing is increased, and air is easily mixed in the inside of the casing when the foaming agent is filled. Then, if air is mixed in, air bubbles will be generated in the heat insulating material after solidification, and if the air bubble portion faces the piping etc., condensation water may be generated in this portion. And this dew condensation water causes a water leak.

The present invention has been made in view of such problems, and the problem to be solved by the present invention is to prevent the retention of the refrigerant to enable stable operation and to perform reliable thermal insulation. It is providing a refrigerant | coolant flow-path switching unit which can prevent a water leak, and an air conditioner provided with the same.

MEANS TO SOLVE THE PROBLEM As a result of earnestly examining in order to solve the said subject, the present inventors found out that the said subject can be solved by doing as follows. That is, the gist of the present invention comprises a plurality of use side units capable of independent cooling and heating operation and a heat source side unit, and a refrigeration cycle is formed between the plurality of use side units and the heat source side unit The refrigerant flow path switching device controls the flow direction of the refrigerant to the plurality of use side units by being disposed in the air conditioner and disposed between the plurality of use side units and the heat source side unit. A unit, a first refrigerant pipe connected to the discharge side of the compressor provided in the heat source side unit, and a refrigerant flowing through the first refrigerant pipe provided by opening and closing the first refrigerant pipe A first on-off valve for controlling the flow, a second refrigerant pipe branched from the first refrigerant pipe and connected to the suction side of the compressor provided in the heat source side unit, and provided in the second refrigerant pipe Opening and closing Thus, the flow of the refrigerant flowing through the second refrigerant pipe is controlled, and a second on-off valve provided at the same position in the height direction as the first on-off valve, the first refrigerant pipe, and the first refrigerant pipe Providing a third refrigerant pipe having a portion further branched from the branch with the second refrigerant pipe and connected to the heat exchanger provided in the use-side unit and extending downward in the direction toward the heat exchanger; The present invention relates to a refrigerant channel switching unit characterized by the above. Other solutions will be described later in the Detailed Description of the Invention.

According to the present invention, it is possible to provide a refrigerant flow switching unit capable of preventing the retention of the refrigerant to enable stable operation and performing reliable thermal insulation to prevent water leakage, and an air conditioner including the same. be able to.

It is a systematic diagram of an air conditioner provided with a refrigerant channel switching unit of this embodiment. It is a top view which shows the connection form of each piping which comprises the refrigerant | coolant flow path switching unit of this embodiment. It is a side view which shows the connection form of each piping which comprises the refrigerant | coolant flow path switching unit of this embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. The respective drawings are schematic, and in order to facilitate understanding of the present invention, a part of the members may be appropriately omitted or simplified, or the internal structure may be shown within the scope of the present invention. May be visualized and shown.

FIG. 1 is a system diagram of an air conditioner 100 provided with a refrigerant flow path switching unit 1 of the present embodiment. The air conditioner 100 is a multi-type air conditioner of simultaneous heating and cooling type that can simultaneously operate cooling and heating for each indoor unit 3. The air conditioner 100 connects the refrigerant flow switching unit 1, the outdoor unit 2, a plurality of indoor units 3 (3 a, 3 b, 3 c, 3 d), a high pressure connecting the refrigerant flow switching unit 1 and the outdoor unit 2. The gas pipe 4, the low pressure gas pipe 5 and the liquid pipe 6, and the gas pipe 7 (7 a, 7 b, 7 c, 7 d) connecting the refrigerant flow path switching unit 1 and the plurality of indoor units 3 are provided. Among these, the high pressure gas pipe 4 is also referred to as a discharge gas pipe, and the low pressure gas pipe 5 is also referred to as a suction gas pipe. And, since the refrigerant channel switching unit 1 and the outdoor unit 2 are connected by three pipes of the high pressure gas pipe 4, the low pressure gas pipe 5 and the liquid pipe 6, the air conditioner 100 is a so-called three pipe system Air conditioner.

Although not shown, the outdoor unit 2 includes a compressor for compressing the refrigerant supplied to the refrigerant channel switching unit 1, an outdoor heat exchanger for exchanging heat between outdoor air and the refrigerant, and the outdoor heat exchanger. An outdoor expansion valve that expands the refrigerant before or after heat exchange in the outdoor heat exchanger (different depending on whether the main cooling or heating is performed) and the flow path of the refrigerant is switched according to the main cooling or main heating. A four-way valve is provided. The high pressure gas pipe 4 is connected to the discharge side of the compressor provided in the outdoor unit 2. On the other hand, the low pressure gas pipe 5 and the liquid pipe 6 are connected to the suction side of the compressor.

Furthermore, although not shown, the indoor unit 3 is an indoor heat exchanger that exchanges heat between indoor air and a refrigerant, and before or after heat exchange is performed in the indoor heat exchanger (indoor And an indoor expansion valve for expanding the refrigerant (depending on the operation mode of the unit). Incidentally, a gas pipe 7 is connected to this indoor heat exchanger.

And these are mutually connected by piping and a refrigerating cycle is formed between the outdoor unit 2 and the indoor unit 3 by flowing a refrigerant through the inside of the said piping. In particular, in the refrigerant flow path switching unit 1 disposed between the outdoor unit 2 and the indoor unit 3, the flow direction of the refrigerant supplied from the outdoor unit 2 to the indoor unit 3 is controlled, whereby the indoor unit 3 is Cooling and heating can be operated at the same time independently of each other.

Specifically, in the indoor unit 3 performing the cooling operation, the flow path is controlled such that the liquid refrigerant in the liquid pipe 6 flows to the indoor unit 3. Then, the liquid refrigerant that has flowed into the indoor unit 3 is expanded (decompressed) by the indoor expansion valve to become a low temperature gas refrigerant, and then the indoor heat exchanger exchanges heat with indoor air to cool the room. Be done. The gas refrigerant heat-exchanged in the indoor heat exchanger is returned to the low pressure gas pipe 5. Further, in the indoor unit 3 performing the heating operation, the flow path is controlled so that the gas refrigerant of the high pressure gas pipe 4 flows to the indoor unit 3. The high temperature gas refrigerant flowing to the indoor unit 3 exchanges heat with indoor air in the above-mentioned indoor heat exchanger, whereby the room is heated. The liquid refrigerant condensed by heat exchange in the indoor heat exchanger is returned to the liquid pipe 6.

FIG. 2 is a top view showing a connection form of the pipes constituting the refrigerant channel switching unit 1 of the present embodiment. In the refrigerant flow switching unit 1, the high pressure gas pipe 4 and the low pressure gas pipe 5 are connected in parallel to the gas pipes 7a to 7d via the high pressure header 15 and the low pressure header 16, respectively. Also, the high pressure gas pipe 4 and the high pressure header 15 are connected via the connection portion 13. Furthermore, the low pressure gas pipe 5 and the low pressure header 16 are connected via the connection portion 14. Each of the high-pressure header 15 and the low-pressure header 16 is provided with a strainer 20. The strainer 20 is for removing foreign matter in the flowing refrigerant. And these are all accommodated in the housing | casing 1a which comprises the refrigerant | coolant flow-path switching unit 1. As shown in FIG. In addition, a circuit board (not shown) for controlling driving of the high-pressure valve electromagnetic coil 17 and the low-pressure valve electromagnetic coil 18 (both will be described later with reference to FIG. 3) is housed on the side of the housing 1a. An electric box 1b is provided.

The connection of the pipes constituting the refrigerant flow switching unit 1 and the configurations of the devices constituting the refrigerant flow switching unit 1 will be described with reference to FIG.

FIG. 3: is a side view which shows the connection form of each piping which comprises the refrigerant | coolant flow path switching unit 1 of this embodiment. The high pressure header 15 connected to the high pressure gas pipe 4 (not shown in FIG. 3) described with reference to FIG. A valve 9 is provided. Incidentally, below the high pressure valve 9, a gas pipe 11a described later is connected. The high pressure header 15 and the high pressure valve 9 are connected at the connection portion 9a. The high pressure valve 9 is a solenoid valve, and the opening and closing of the high pressure valve 9 is controlled by a high pressure valve electromagnetic coil 17 disposed above the high pressure valve 9. Specifically, by controlling the energization of the high pressure valve electromagnetic coil 17, the opening and closing of the high pressure valve 9 is controlled. Then, the flow of the high pressure gas refrigerant from the high pressure gas pipe 4 is controlled by controlling the opening and closing of the high pressure valve 9.

In the low pressure header 15 connected to the low pressure gas pipe 5 (not shown in FIG. 3) described with reference to FIG. 2, the low pressure header 15 at the upper right viewed from the low pressure gas pipe 5 and its connecting portion 14 A valve 10 is provided. Incidentally, the low pressure valve 10 is connected to a gas pipe 11b described later at the connection portion 10a. The low pressure valve 10 is a solenoid valve, and the opening and closing of the low pressure valve 10 is controlled by a low pressure valve electromagnetic coil 18 disposed above the low pressure valve 10. Specifically, the control of energization of the low pressure valve electromagnetic coil 18 controls the opening and closing of the low pressure valve 10. By controlling the opening and closing of the low pressure valve 10, the flow of low pressure gas refrigerant from the low pressure gas pipe 5 is controlled.

In the refrigerant flow path control unit 1 of the present embodiment, the high pressure valve 9 and the low pressure valve 10 have the same specifications and the same size (shape). Further, both the high pressure valve electromagnetic coil 17 and the low pressure valve electromagnetic coil 18 have the same specifications and the same size (shape). The same specification here means that the performance such as the relationship between the opening degree and the flow rate is the same. Moreover, the same shape here means that the external shape is the same, and in the side view, the height dimension and the width dimension are the same. Therefore, the same specifications and the same size (shape) refer to, for example, the same manufacturer of the same model number or the like. The integrated body of the high pressure valve 9 and the high pressure valve electromagnetic coil 17 and the integrated body of the low pressure valve 10 and the low pressure valve electromagnetic coil 18 are disposed at the same position in the height direction. Therefore, in FIG. 3, the broken line connecting the upper end of the high pressure valve electromagnetic coil 17 and the upper end of the low pressure valve electromagnetic coil 18 and the broken line connecting the lower end of the high pressure valve 9 and the lower end (Details will be described later, but “parallel” as used herein is a concept including “substantially parallel”).

With such a positional relationship between the high pressure valve 9 and the low pressure valve 10, the upper surface (ceiling) of the housing 1a can be lowered because one of the valves does not protrude upward. Therefore, it is prevented that a waste space arises inside the housing | casing 1a, and the quantity of the foaming agent as a heat insulating material 19 (after-mentioned) filled with an inside can be reduced. Therefore, it is fully prevented that air mixes at the time of filling of a foaming agent, and it can aim at heat insulation more reliably and can prevent generation | occurrence | production of dew condensation water.

Further, a gas pipe 11 a extends below the high pressure valve 9, and the pipe branches in the left-right direction at a branch portion 22 existing at the lower end of the pipe. Of the pipes branched at the branch portion 22, the pipe extending to the right is the gas pipe 11b, and the pipe extending to the left is the gas pipe 11c. Among these, the side of the gas pipe 11 b is the side facing the low pressure valve 10. The low pressure gas pipe 5 and the indoor unit 3 are mainly connected via the low pressure header 16 and the

gas pipes

11b and 11c. On the other hand, the side of the gas pipe 11 c is the side facing the indoor unit 3. The high pressure gas pipe 4 and the indoor unit 3 are mainly connected via the high pressure header 15 and the

gas pipes

11a and 11c.

The gas pipe 11b extending rightward from the branched portion 22 has a portion extending vertically upward in addition to a portion extending to the horizontal portion. Specifically, the gas pipe 11 b extends horizontally rightward from the branch portion 22 and then vertically upward, and is configured to further extend rightward at its upper end. Therefore, as a whole, the gas pipe 11b constituting the branch portion 22 to the low pressure valve 10 extends upward. Thus, the flow path is controlled such that the flow direction of the refrigerant to the outdoor expansion valve in the outdoor unit 2 is in only one direction.

Further, the gas pipe 11 c extending to the left from the branch portion 22 is formed horizontally in the vicinity of the branch portion 22. However, the gas pipe 11c includes, in addition to the portion formed in the horizontal direction, a portion having a slope that descends in the left direction (the direction of the indoor heat exchanger of the indoor unit 3). A gas pipe 7 connected to the indoor unit 3 is connected via a connecting portion 22 at the end of the horizontal portion disposed on the left side of the portion having the falling slope. In this way, when the air conditioner 100 is turned off or shut down, the refrigerant present inside the pipe of the refrigerant flow switching unit 1 naturally becomes an indoor unit due to the inclined portion under the gas pipe 11c. It will flow to 3 direction. Therefore, the refrigerant is prevented from staying in the refrigerant channel switching unit 1.

And the strainer 20 is equipped in the part which has the inclination which descend | falls in the gas pipe 11c. As described above, the strainer 20 removes foreign matter in the flowing refrigerant. The sloped arrangement of the strainer 20 prevents the refrigerant from staying in the strainer 20 as well.

Further, a heat insulating material 19 is disposed inside the housing 1a so that all the members other than the high pressure valve electromagnetic coil 17 and the low pressure valve electromagnetic coil 18 are covered. The heat insulating material 19 is, for example, urethane foam. The heat insulating material 19 is formed by filling the urethane foam (foaming agent) through an opening (not shown) or the like formed on the surface of the housing 1a and then solidifying it after housing the piping etc. inside the housing 1a. Ru.

The position in the height direction of connection portion 21 (the position of the lowermost dashed line in FIG. 3), the position in the height direction of branch portion 22 (the position of the alternate long and short dash line in FIG. 3), and the height of connection portion 10a The respective members are arranged so as to be higher in this order with the longitudinal position (the position of the uppermost dashed line in FIG. 3). That is, as shown in FIG. 3, the position in the height direction of the branched portion 22 of the

gas pipes

11b and 11c is longer than the position in the height direction of the connecting portion 21 between the gas pipe 11c and the gas pipe 7 It is only at a high position. Further, the positions in the height direction of the connection portion 9a in the high pressure valve 9 and the connection portion 10a in the low pressure valve 10 are higher by the length B than the positions in the height direction of the branched portions 22 of the

gas pipes

11b and 11c. It has become. As described above, since the high pressure valve 9 and the low pressure valve 10 have the same specifications and the same size (shape), the positions in the height direction of the connecting portion 9a and the connecting portion 10a are the same.

In this way, when the air conditioner 100 is turned off or shut down, the refrigerant in the refrigerant channel switching unit 1 is sent to the indoor unit 3 through the connection portion 21 and the gas pipe 7 disposed at the lowermost position. I will head. Therefore, stagnation of the refrigerant is unlikely to occur, and stable operation is possible even when the air conditioner 100 is operated again. Moreover, since it becomes difficult to also hold refrigeration oil besides a refrigerant, corrosion of piping etc. can be controlled.

Furthermore, the positions in the height direction of the connection portion 9a and the connection portion 10a are the same, and the positions in the height direction of the high pressure valve 9 and the low pressure valve 10 are the same. The dimension of the switching unit 1 in the height direction can be reduced. Therefore, when filling the foaming agent which comprises the heat insulating material 19, the filling amount of a foaming agent can be reduced. Thereby, mixing of air is prevented at the time of filling, and since reliable thermal insulation can be performed, generation | occurrence | production of dew condensation water can be suppressed and a water leak can be prevented.

As mentioned above, although this embodiment was described referring to drawings suitably, this embodiment is not limited at all to the above-mentioned example.

For example, although the gas pipe 11c is configured to extend downward toward the indoor heat exchanger of the indoor unit 3, the gas pipe 11c is inclined downward in the direction toward the left direction (indoor heat exchanger), but extends downward. If there is, it may be done in any way. For example, the gas pipe 11c may be formed by connecting a first pipe extending in the horizontal direction, a second pipe extending in the vertical direction, and a third pipe extending in the horizontal direction in this order. In this case, the connection portion 21 is connected to the left end of the first pipe, the second pipe is connected to the right end of the first pipe, and the left end of the third pipe is connected to the upper end of the second pipe. And the branched portion 22 is connected to the right end of the third pipe.

Also, for example, the strainer 20 provided in the gas pipe 11c is provided at a portion having a slope downward to the left, but in addition to being provided at this portion, or at being provided at this portion Alternatively, the strainer 20 may be provided in a horizontally extending portion other than the portion. The strainer 20 is provided on the horizontal portion, which facilitates processing.

Furthermore, for example, although the high pressure valve 9 and the low pressure valve 10 have the same specifications and the same size (shape), for example, this does not have to be the case. That is, if the upper ends of the two valves (or upper ends of the electromagnetic coils) have the same height (may be substantially the same height) even if they have different specifications and sizes, the dimension in the height direction of the housing 1a And the effects of the present invention are exhibited.

Further, although the high pressure valve 9 and the low pressure valve 10 are disposed at the same position in the height direction, they do not have to be at the same height position (that is, the broken line shown in FIG. Some deviation (ie, the broken lines shown in FIG. 3 are, for example, approximately parallel) within a range that does not significantly impair the effects of the present invention, for example, several mm, is acceptable.

1 refrigerant flow path switching unit 1a case 1b electric box 2 outdoor unit (heat source side unit)
3, 3a, 3b, 3c, 3d Indoor unit (user side unit)
4 High pressure gas pipe (first refrigerant piping)
5 Low pressure gas pipe (second refrigerant piping)
6

Liquid pipes

7, 7a, 7b, 7c, 7d Gas pipes (third refrigerant piping)
9 High pressure valve (1st on-off valve)
10 Low pressure valve (1st on-off valve)
11a Gas pipe (first refrigerant piping)
11b Gas pipe (second refrigerant piping)
11c Gas pipe (third refrigerant piping)
12 gas pipe 13 connecting high pressure valve and low pressure valve connection 14 connection 15 high pressure header (first refrigerant piping)
16 Low pressure header (second refrigerant piping)
17 high pressure valve electromagnetic coil 18 low pressure valve electromagnetic coil 19 heat insulator 20 strainer 22 branch portion (branch)
100 air conditioner

Claims

The air conditioner includes a plurality of use side units capable of cooling and heating independently and a heat source side unit, and a refrigeration cycle is formed between the plurality of use side units and the heat source side unit. A refrigerant channel switching unit, which is disposed between the plurality of use side units and the heat source side unit to control the flow direction of the refrigerant to the plurality of use side units,
A first refrigerant pipe connected to a discharge side of a compressor provided in the heat source side unit;
A first on-off valve provided in the first refrigerant pipe and controlling the flow of the refrigerant flowing through the first refrigerant pipe by opening and closing the first refrigerant pipe;
A second refrigerant pipe which is branched from the first refrigerant pipe and connected to the suction side of the compressor provided in the heat source side unit;
The second refrigerant pipe is provided in the second refrigerant pipe and controls opening / closing of the refrigerant flowing through the second refrigerant pipe by opening and closing, and a second opening and closing provided at the same position as the first opening / closing valve in the height direction With the valve,
A third refrigerant having a portion further branched from the branch between the first refrigerant pipe and the second refrigerant pipe and connected to a heat exchanger provided in the use-side unit and extending downward in the direction toward the heat exchanger And a pipe.
The refrigerant flow switching unit according to claim 1, wherein the downwardly extending portion formed in the third refrigerant pipe is a portion having a slope which is lowered toward the heat exchanger.
The refrigerant channel switching unit according to claim 1 or 2, wherein the third refrigerant pipe is provided with a strainer for removing foreign matter in the flowing refrigerant in the portion extending downward. .
The third refrigerant pipe has a horizontally extending portion in addition to the downwardly extending portion,
The refrigerant | coolant flow-path switching unit of Claim 1 or 2 characterized by the strainer which removes the foreign material in the flowing refrigerant | coolant in the part extended in the said horizontal part.
The refrigerant flow switching unit according to claim 1, wherein the first on-off valve and the second on-off valve have the same specifications and the same size.
Multiple user-side units that can be independently operated by cooling and heating, and
A heat source side unit in which a refrigeration cycle is formed between the plurality of user side units;
The first refrigerant pipe connected to the discharge side of the compressor provided in the heat source side unit and the first refrigerant pipe are provided, and the flow of the refrigerant flowing through the first refrigerant pipe is controlled by opening and closing the first refrigerant pipe It is provided in one on-off valve, a second refrigerant pipe which is branched from the first refrigerant pipe and connected to the suction side of the compressor provided in the heat source side unit, and is provided in the second refrigerant pipe and is opened and closed by opening and closing. A second on-off valve provided at the same position in the height direction as the first on-off valve while controlling the flow of the refrigerant flowing through the second refrigerant pipe, the first refrigerant pipe, and the second refrigerant pipe And a third refrigerant pipe having a portion further branched from the branch and connected to the heat exchanger provided in the use side unit and extending downward in the direction toward the heat exchanger; Unit and the heat source side unit By being disposed between, characterized in that and a refrigerant flow path switching unit for controlling the flow direction of the refrigerant to the plurality of utilization side units, the air conditioner.