CN111448424A

CN111448424A - Air conditioner

Info

Publication number: CN111448424A
Application number: CN201880078660.8A
Authority: CN
Inventors: 松本祥志; 吉冈俊
Original assignee: Daikin Industries Ltd
Current assignee: Daikin Industries Ltd
Priority date: 2017-12-05
Filing date: 2018-11-28
Publication date: 2020-07-24
Anticipated expiration: 2038-11-28
Also published as: AU2018380495A1; US20210231343A1; AU2018380495B2; EP3722686A4; CN111448424B; JP2019100643A; WO2019111783A1; JP6673318B2; EP3722686A1

Abstract

An air conditioner includes an outdoor unit having an outdoor heat exchanger, an indoor unit (20) having an indoor heat exchanger (25) and an indoor fan (28) that supplies air to the indoor heat exchanger, a gas refrigerant communication tube (GP) that connects the outdoor unit and the indoor unit, and a liquid refrigerant communication tube (L P). The air conditioner circulates a refrigerant in a refrigerant circuit including the outdoor heat exchanger, the indoor heat exchanger, and the refrigerant communication tubes (GP, L P) to perform air conditioning of an air conditioning target space in which the indoor unit is disposed.A refrigerant circuit includes refrigerant tubes (21, 22) made of a metal material, refrigerant communication tubes (GP, L P) made of a metal material different from the refrigerant tubes (21, 22), and connections (21a, 22a) between the refrigerant tubes (21, 22) and the liquid refrigerant communication tubes (GP, L P). The connections are disposed in a non-ventilation space (90).

Description

Air conditioner

Technical Field

The present disclosure relates to an air conditioner, and more particularly, to an air conditioner having a connection portion to which different types of metal pipes are connected.

Background

Conventionally, a refrigerant circuit of an air conditioner is sometimes provided with a different metal connecting portion to which different kinds of metal pipes are connected. Electrolytic corrosion may occur between dissimilar metals due to differences in ionization tendency of the metals. In particular, when dew condensation occurs in the pipe and water droplets containing metal ions of one metal come into contact with the pipe made of the other metal material, electrolytic corrosion of the pipe tends to be a problem.

In order to solve the above problem, patent document 1 (japanese patent laid-open No. 2012-184870) describes a technique of providing a pipe with a U-shaped portion or an inverted U-shaped portion that suppresses movement of condensed water and the like.

Disclosure of Invention

Technical problem to be solved by the invention

However, patent document 1 (japanese patent laid-open No. 2012-184870) does not describe the suppression of dew condensation at the dissimilar metal joint.

The technical problem of the present disclosure is to provide an air conditioner in which condensed water is not easily generated at a connection portion to which different types of metal pipes are connected, and electrolytic corrosion at the connection portion is easily suppressed.

Technical scheme for solving technical problem

The air conditioner includes a heat source-side unit, a usage-side unit, and a refrigerant communication tube. The heat source side unit has a heat source side heat exchanger. The use-side unit includes a use-side heat exchanger and a use-side fan that supplies air to the use-side heat exchanger. The refrigerant communication tube connects the heat-source-side unit and the usage-side unit. The air conditioner circulates a refrigerant in a refrigerant circuit including the heat source-side heat exchanger, the usage-side heat exchanger, and the refrigerant communication tube, and air-conditions an air-conditioned space in which the usage-side unit is disposed. The refrigerant circuit includes a first pipe made of a metal material, a second pipe made of a metal material different from the metal material of the first pipe, and a connection portion between the first pipe and the second pipe. The connecting part is arranged in the non-ventilation space.

In the air conditioner, the connection portion of the dissimilar metal is disposed in the non-ventilation space. Therefore, in the air conditioner, condensed water is less likely to be generated at the connection portion, and electrolytic corrosion at the connection portion is more likely to be suppressed.

Preferably, in the air conditioner, the utilization-side unit further has a casing. The housing accommodates the use-side heat exchanger and the use-side fan. The air conditioner further includes a wind shielding member forming a non-ventilation space in the casing. The connecting portion is disposed in a non-ventilation space formed in the housing by the wind shielding member.

Here, since the non-ventilation space is formed in the housing by the wind shielding member, the connection portion can be disposed even in the housing in which the flow of air is likely to occur due to the presence of the use-side fan.

Preferably, in the air conditioner, the wind shielding member is disposed downstream of the usage-side fan and upstream of the connection portion in the air blowing direction of the usage-side fan. The wind blocking member forms a non-ventilation space in which the connection portion is disposed on a downstream side of the wind blocking member in a blowing direction of air by the side fan.

Here, the presence of the wind shielding member suppresses the collision of the air blown out from the side fan against the connection portion. Therefore, electrolytic corrosion at the connection portion can be suppressed.

Preferably, the air conditioner further includes a condensation prevention member disposed around the connection portion and different from the wind shielding member.

Here, since the connection portion is disposed in the non-air-permeable space in the housing formed by the wind shielding member and the dew condensation preventing member is provided around the connection portion, electrolytic corrosion at the connection portion is particularly easily suppressed.

Preferably, the air conditioner further includes a cover member that covers a periphery of the connection portion and forms a non-ventilation space inside the cover member.

Here, by forming the non-ventilation space around the connection portion, the promotion of electrolytic corrosion at the connection portion can be suppressed.

Preferably, in the air conditioner, the first pipe is a pipe provided in the use-side unit. The utilization side unit also has a housing. The housing accommodates the use-side heat exchanger and the use-side fan. The connecting part is arranged outside the shell.

Here, since the connection portion is disposed outside the casing that houses the usage-side fan and in which the air flows, the connection portion can be easily disposed in the non-ventilation space.

Preferably, in the air conditioner, the non-ventilation space is a space in which the air speed is 0.5 m/sec or less when the air conditioner is operating.

Here, since the wind speed in the non-ventilation space is 0.5 m/sec or less even when the air conditioner is operating, electrolytic corrosion at the connection portion can be suppressed.

Preferably, in the air conditioner, the non-ventilation space is a space: the wind speed in the non-ventilation space at which the usage-side fan has the maximum wind volume is not higher than 1/5 of the wind speed in the ventilation space at which the air blown by the usage-side fan passes when the usage-side fan has the maximum wind volume.

Here, the non-air-space is a space in which the wind speed when the maximum wind volume is set by the utilization-side fan is equal to or less than 1/5 of the wind speed of the air-space, and therefore electrolytic corrosion at the connection portion can be suppressed.

Preferably, in the air conditioner, one of the metal material of the first pipe and the metal material of the second pipe is aluminum or an aluminum alloy, and the other is copper or a copper alloy.

Here, electrolytic corrosion of the connection portion between the aluminum/aluminum alloy pipe and the copper/copper alloy pipe at the connection portion can be suppressed.

Preferably, in the air conditioner, the usage-side unit is a ceiling-mounted unit that is mounted on a ceiling of the space to be air-conditioned.

Drawings

Fig. 1 is a schematic configuration diagram of an air conditioner according to an embodiment.

Fig. 2 is a perspective view of an indoor unit of the air conditioner of fig. 1.

Fig. 3 is a schematic sectional view of the indoor unit in a state of being mounted on a ceiling in the direction of the arrow iii-iii of fig. 2.

Fig. 4 is a bottom view schematically showing a schematic structure of the indoor unit of fig. 2. Fig. 4 shows an indoor unit with the decorative panel removed.

Fig. 5 is a schematic cross-sectional view in the direction of the arrows v-v of fig. 4.

Fig. 6 is a bottom view schematically showing a schematic structure of an indoor unit according to modification B. Fig. 6 shows an indoor unit with the decorative panel removed.

Fig. 7 is a perspective view of the indoor heat exchanger of fig. 6.

Fig. 8 is a bottom view schematically showing a schematic structure of an indoor unit according to modification C. Fig. 8 shows an indoor unit with the decorative panel removed.

Fig. 9 is a bottom view schematically showing a schematic configuration of an indoor unit according to modification E. Fig. 9 shows an indoor unit with the decorative panel removed.

Detailed Description

Hereinafter, an air conditioner 100 according to an embodiment will be described with reference to the drawings.

In the following embodiments, expressions of up, down, left, right, front, and rear may be used to describe the direction and positional relationship, but the directions indicated by the expressions follow the directions indicated by arrows in the drawings.

(1) Overview

Fig. 1 is a schematic configuration diagram of an air conditioner 100.

The air conditioner 100 is a device that performs cooling operation or heating operation to air-condition a target space. Specifically, the air conditioner 100 includes a refrigerant circuit RC and performs a vapor compression refrigeration cycle.

The air conditioner 100 mainly includes an outdoor unit 10 as an example of a heat source-side unit, an indoor unit 20 as an example of a usage-side unit, a gas refrigerant communication tube GP as an example of a refrigerant communication tube connecting the outdoor unit 10 and the indoor unit 20, and a liquid refrigerant communication tube L P.

The gas refrigerant communication tube GP and the liquid refrigerant communication tube L P are pipes laid at the installation site of the air conditioner 100, the pipe diameters and the pipe lengths of the gas refrigerant communication tube GP and the liquid refrigerant communication tube L P are independently selected in accordance with the design specifications and the installation environment, and in the present embodiment, the gas refrigerant communication tube GP and the liquid refrigerant communication tube L P are pipes made of copper or a copper alloy.

In the air conditioner 100, the outdoor unit 10 and the indoor unit 20 are connected by the gas refrigerant connection tube GP and the liquid refrigerant connection tube L P, and the refrigerant circuit RC., which constitutes the refrigerant circuit RC, includes the outdoor heat exchanger 13, which will be described later, of the outdoor unit 10, the indoor heat exchanger 25, which will be described later, of the indoor unit 20, the gas refrigerant connection tube GP, and the liquid refrigerant connection tube L P, the air conditioner 100 circulates the refrigerant in the refrigerant circuit RC, and air conditioning of the air-conditioning target space in which the indoor unit 20 is disposed is performed.

Further, HFC refrigerant such as R32 or R410A is sealed in the refrigerant circuit RC. However, the type of the refrigerant is not limited to R32 or R410A, and may be HFO1234yf, HFO1234ze (E), a mixed refrigerant of these refrigerants, or the like.

The refrigerant circuit RC includes a first pipe made of a metal material, a second pipe made of a metal material different from the metal material of the first pipe, and a connection portion between the first pipe and the second pipe.

Specifically, the refrigerant circuit RC has the gas refrigerant tube 21 of the indoor unit 20 made of aluminum or an aluminum alloy, the gas refrigerant communication tube GP made of copper or a copper alloy, and the connection 21a between the gas refrigerant tube 21 and the gas refrigerant communication tube GP, and further, the refrigerant circuit RC has the liquid refrigerant tube 22 of the indoor unit 20 made of aluminum or an aluminum alloy, the liquid refrigerant communication tube L P made of copper or a copper alloy, and the connection 22a between the liquid refrigerant tube 22 and the liquid refrigerant communication tube L P, and since the connection 21a and the connection 22a are connections of dissimilar metals, electrolytic corrosion is likely to occur.

The details of the outdoor unit 10, the indoor unit 20, and the

connection units

21a and 22a will be described below.

(2) Detailed structure

(2-1) outdoor Unit

The outdoor unit 10 is a unit installed outdoors.

The outdoor unit 10 mainly includes a compressor 11, a flow direction switching mechanism 12, an outdoor heat exchanger 13, an expansion mechanism 14, and an outdoor fan 15 (see fig. 1).

The outdoor unit 10 includes a suction pipe 16a, a discharge pipe 16b, a first gas refrigerant pipe 16c, a liquid refrigerant pipe 16d, and a second gas refrigerant pipe 16e (see fig. 1), the suction pipe 16a connects the flow direction switching mechanism 12 and the suction side of the compressor 11, the discharge pipe 16b connects the discharge side of the compressor 11 and the flow direction switching mechanism 12, the first gas refrigerant pipe 16c connects the flow direction switching mechanism 12 and the gas side end of the outdoor heat exchanger 13, the liquid refrigerant pipe 16d connects the liquid side end of the outdoor heat exchanger 13 and the liquid refrigerant communication pipe L p, the expansion mechanism 14 is provided in the liquid refrigerant pipe 16d, the second gas refrigerant pipe 16e connects the flow direction switching mechanism 12 and the gas refrigerant communication pipe GP.

(2-1-1) compressor

The compressor 11 is a device that sucks in, compresses, and discharges a low-pressure gas refrigerant. The compressor 11 is a compressor that is frequency-variable controlled and can adjust the rotation speed of the motor (can adjust the capacity). The rotation speed of the compressor 11 is adjusted by a control unit, not shown, according to the operating conditions. The compressor 11 may be a compressor in which the rotational speed of the motor is constant.

(2-1-2) flow direction switching mechanism

The flow direction switching mechanism 12 is a mechanism that switches the flow direction of the refrigerant in the refrigerant circuit RC according to the operation mode (cooling operation mode/heating operation mode). In the present embodiment, the flow direction switching mechanism 12 is a four-way selector valve.

In the cooling operation mode, the flow direction switching mechanism 12 switches the flow direction of the refrigerant in the refrigerant circuit RC such that the refrigerant discharged from the compressor 11 is sent to the outdoor heat exchanger 13. Specifically, in the cooling operation mode, the flow direction switching mechanism 12 causes the suction pipe 16a to communicate with the second gas refrigerant pipe 16e, and causes the discharge pipe 16b to communicate with the first gas refrigerant pipe 16c (see the solid line in fig. 1). In the heating operation mode, the flow direction switching mechanism 12 switches the flow direction of the refrigerant in the refrigerant circuit RC such that the refrigerant discharged from the compressor 11 is sent to the indoor heat exchanger 25. Specifically, in the heating operation mode, the flow direction switching mechanism 12 causes the suction pipe 16a to communicate with the first gas refrigerant pipe 16c, and causes the discharge pipe 16b to communicate with the second gas refrigerant pipe 16e (see the broken line in fig. 1).

The flow direction switching mechanism 12 is not limited to a four-way selector valve, and may be configured by combining a plurality of solenoid valves and refrigerant tubes to switch the flow direction of the refrigerant.

(2-1-3) outdoor Heat exchanger

The outdoor heat exchanger 13 is an example of a heat source side heat exchanger. The outdoor heat exchanger 13 is a heat exchanger that functions as a condenser of the refrigerant during the cooling operation and functions as an evaporator of the refrigerant during the heating operation. The outdoor heat exchanger 13 includes a plurality of heat transfer tubes and a plurality of heat transfer fins (not shown).

(2-1-4) expansion mechanism

The expansion mechanism 14 is a mechanism for decompressing the high-pressure refrigerant flowing thereinto. In the present embodiment, the expansion mechanism 14 is an electrically operated valve whose opening degree can be adjusted. The opening degree of the expansion mechanism 14 is appropriately adjusted according to the operating conditions. The expansion mechanism 14 is not limited to an electrically operated valve, and may be a capillary tube or the like.

(2-1-5) outdoor Fan

The outdoor fan 15 is a blower that generates an air flow that flows into the outdoor unit 10 from the outside, flows through the outdoor heat exchanger 13, and flows out of the outdoor unit 10. The outdoor fan 15 is driven under control by a control unit, not shown, during operation, and the rotation speed thereof is appropriately adjusted.

(2-2) indoor Unit

Fig. 2 is a perspective view of the indoor unit 20, fig. 3 is a schematic sectional view of the indoor unit 20 in a state of being attached to a ceiling surface C L in the direction of the arrow iii-iii in fig. 2, and fig. 4 is a schematic view showing a schematic configuration of the indoor unit 20 when viewed from below.

The indoor unit 20 is a ceiling-mounted unit that is mounted on the ceiling of the air-conditioned space. In particular, the indoor unit 20 is a so-called ceiling-embedded type unit. The indoor unit 20 mainly includes a casing 30, an indoor heat exchanger 25, and an indoor fan 28 (see fig. 2 to 4).

(2-2-1) outer case

The casing 30 is a housing that accommodates various structures of the indoor unit 20. The casing 30 mainly houses the indoor heat exchanger 25 and the indoor fan 28 (see fig. 3).

As shown in fig. 3, the housing 30 is inserted into an opening of a ceiling surface C L formed in the target space, and is provided in a ceiling back side space cs formed between the ceiling surface C L and an upper floor surface or a roof, the housing 30 includes a ceiling panel 31a, side walls 31b, a bottom panel 31C, and a decorative panel 32 (see fig. 2 and 3).

The top plate 31a is a member constituting the top surface portion of the housing 30, and is formed in a substantially octagonal shape in which long sides and short sides are alternately continuous (see fig. 4). However, the shape of the top plate 31a is an example, and may be, for example, a substantially quadrangular shape.

The side wall 31b is a member that constitutes a side portion of the housing 30, and is configured in an approximately octagonal pillar shape corresponding to the shape of the top plate 31a, an opening 30a is formed in the side wall 31b, and this opening 30a is used to insert (pull) the gas refrigerant communication tube GP and the liquid refrigerant communication tube L P into the housing 30 (see fig. 4). in the present embodiment, the gas refrigerant communication tube GP and the liquid refrigerant communication tube L P are inserted from the opening 30a of the side wall 31b, and in the housing 30, the gas refrigerant communication tube GP is connected to the gas refrigerant tube 21, and the liquid refrigerant communication tube L P is connected to the liquid refrigerant tube 22. that is, in the present embodiment, the connection portion 21a and the connection portion 22a are disposed within the housing 30. the bottom plate 31c is a member that constitutes a bottom portion of the housing 30, and in the center thereof, an approximately quadrangular large opening 311 (see fig. 3) is formed, and a plurality of openings 312 (see fig. 3 and 4) are formed around the large opening 311 that is located on the bottom surface side (target space side) of the bottom plate 31 c.

The decorative panel 32 is a plate-like member exposed to the target space, and has a substantially quadrangular shape in plan view, the decorative panel 32 is fitted into an opening (see fig. 3) provided in the ceiling surface C L, the decorative panel 32 is formed with an air inlet 33 and a plurality of air outlets 34, the air inlet 33 is formed in a substantially quadrangular shape at a position in the central portion of the decorative panel 32 that partially overlaps the large opening 311 of the bottom plate 31C in plan view, the plurality of air outlets 34 are formed so as to surround the air inlet 33 around the air inlet 33, each air outlet 34 is disposed at a position corresponding to the opening 312 of the bottom plate 31C, and air sucked from the air inlet 33, passed through the indoor heat exchanger 25, and blown out from each opening 312 is blown out from the air outlet 34 corresponding to the opening 312 (see fig. 3).

(2-2-2) indoor Heat exchanger

The indoor heat exchanger 25 is an example of a use-side heat exchanger. The entire indoor heat exchanger 25 (including the heat exchange portion 40 described later and the header connecting the gas refrigerant tube 21 and the liquid refrigerant tube 22) is made of aluminum or an aluminum alloy. One ends of the gas refrigerant pipe 21 and the liquid refrigerant pipe 22 made of aluminum or an aluminum alloy are connected to the indoor heat exchanger 25.

The indoor heat exchanger 25 includes a plurality of rows (two rows in this case) of heat exchange portions 40, and the heat exchange portions 40 are formed by stacking a plurality of flat multi-hole tubes 45 in an up-down direction. The rows of the heat exchange portions 40 are arranged along the indoor air flow AF generated by the indoor fan 28 (see fig. 5) described later. Each heat exchange portion 40 mainly includes a plurality of flat perforated tubes 45 and a plurality of heat transfer fins 48 (see fig. 5).

The flat perforated tube 45 has a flat shape in cross section. A plurality of refrigerant flow paths (flat tube flow paths 451) extending in the extending direction of the flat multi-hole tubes 45 are formed inside the flat multi-hole tubes 45 (see fig. 5). The plurality of flat tube channels 451 are arranged in the direction of the indoor air flow AF in the flat perforated tube 45 (see fig. 5).

The heat transfer fins 48 are flat plate-like members that increase the heat transfer area between the flat perforated tubes 45 and the indoor air flow AF. The heat transfer fins 48 are made of aluminum or aluminum alloy. Each of the heat transfer fins 48 extends so as to intersect the flat multi-hole tubes 45 with the stacking direction (vertical direction) of the flat multi-hole tubes 45 as the longitudinal direction. The heat transfer fin 48 has a plurality of slits 48a formed therein in a vertically spaced arrangement. A flat perforated tube 45 (see fig. 5) is inserted into each slit 48 a. In each heat exchange portion 40, a plurality of heat transfer fins 48 are arranged at intervals in the extending direction of the flat perforated tubes 45.

The indoor heat exchanger 25 (heat exchange portion 40) is bent at three positions at approximately 90 degrees in a plan view, and is arranged in a substantially quadrangular shape (see fig. 3). The indoor heat exchanger 25 is disposed so as to surround the suction port 33 and be surrounded by the discharge port 34 in a plan view. In other words, the indoor heat exchanger 25 is formed in an approximate "ロ" shape. The indoor heat exchanger 25 is disposed so as to surround the indoor fan 28. When the refrigerant flows into the indoor heat exchanger 25 from the gas refrigerant pipe 21, the refrigerant flowing through the flat tube flow paths 451 exchanges heat with air passing through the indoor heat exchanger 25 from the inside toward the outside, and flows out from the liquid refrigerant pipe 22. When the refrigerant flows into the indoor heat exchanger 25 from the liquid refrigerant tube 22, the refrigerant flowing through the flat tube flow paths 451 exchanges heat with air passing through the indoor heat exchanger 25 from the inside toward the outside, and flows out from the gas refrigerant tube 21.

(2-2-3) indoor Fan

The indoor fan 28 is an example of a utilization-side fan. The indoor fan 28 supplies air to the indoor heat exchanger 25, which is one example of the use-side heat exchanger.

The indoor fan 28 is a blower that generates an air flow (indoor air flow AF, see fig. 5, etc.) that flows into the indoor unit 20 from outside the casing 30, flows through the outdoor heat exchanger 25, and flows out of the indoor unit 20. The indoor fan 28 is driven under control by a control unit, not shown, during operation, and the rotation speed thereof is appropriately adjusted.

An indoor fan 28 is disposed in the center portion of the casing 30, and the indoor heat exchanger 25 is disposed so as to surround the indoor fan 28. The indoor fan 28 partially overlaps the intake port 33 in a plan view (see fig. 4).

In the casing 30, there are formed an intake flow path FP1 for guiding the indoor air flow AF flowing into the casing 30 through the intake port 33 to the indoor heat exchanger 25, and an outlet flow path FP2 for sending the indoor air flow AF passing through the indoor heat exchanger 25 to the outlet port 34 (see fig. 3) through the outlet flow path FP 2. The outlet flow path FP2 is arranged outside the suction flow path FP1 so as to surround the suction flow path FP 1. The suction flow path FP1 and the discharge flow path FP2 are examples of the ventilation space.

In the above-described embodiment, by disposing the intake port 33, the discharge port 34, the intake flow path FP1, the discharge flow path FP2, the indoor heat exchanger 25, and the indoor fan 28, the indoor air flow AF flows through the following path in the indoor unit 20 during operation of the indoor fan 28.

The indoor air flow AF generated by the indoor fan 28 flows into the casing 30 through the suction port 33. The indoor air flow AF blown out from the indoor fan 28 is blown out radially from the indoor fan 28 in a bottom view (see fig. 4), and is guided to the indoor heat exchanger 25 through the suction flow path FP 1. The indoor air flow AF guided to the indoor heat exchanger 25 exchanges heat with the refrigerant in the indoor heat exchanger 25, is sent to the outlet port 34 via the outlet flow path FP2, and is blown out from the outlet port 34 to the target space.

(2-3) connecting part

The connection portion 21a is a connection portion between the gas refrigerant tube 21 of the indoor unit 20, which is an example of the first pipe, and the gas refrigerant communication tube GP, which is an example of the second pipe. The gas refrigerant pipe 21 is a pipe made of aluminum or aluminum alloy as described above. The gas refrigerant communication tube GP is a tube made of copper or a copper alloy as described above.

The connection portion 21a is a connection portion of a dissimilar metal. In the present embodiment, the gas refrigerant tube 21 and the gas refrigerant communication tube GP are brazed using a brazing material. Note that brazing is merely an example of a method of connecting the gas refrigerant tube 21 and the gas refrigerant communication tube GP. For the connection of the gas refrigerant tube 21 and the gas refrigerant communication tube GP, a connection method such as a friction welding method or a eutectic welding method may be employed. Further, as for the connection between the gas refrigerant tube 21 and the gas refrigerant communication tube GP, any method other than the examples may be appropriately selected as long as it satisfies the design specifications (for example, a required connection strength can be secured).

The connection portion 22a is a connection portion between the liquid refrigerant tube 22 of the indoor unit 20, which is an example of the first pipe, and the liquid refrigerant communication tube L P, which is an example of the second pipe, the liquid refrigerant tube 22 is a pipe made of aluminum or an aluminum alloy as described above, the liquid refrigerant communication tube L P is a pipe made of copper or a copper alloy as described above, the connection portion 22a is also a connection portion of a different metal, and the connection of the liquid refrigerant tube 22 and the liquid refrigerant communication tube L P at the connection portion 22a may be performed by the same connection method as the connection portion 21 a.

In order to prevent electrolytic corrosion by suppressing the generation of condensed water at the

connection portions

21a and 22a, the

connection portions

21a and 22a are disposed in the non-ventilation space 90.

In particular, in the present embodiment, the connection portion 21a and the connection portion 22a are disposed in the non-ventilation space 90 formed in the housing 30. The non-ventilation space 90 is a space outside the ventilation space in the casing 30 including the suction inflow FP1 and the blowing flow path FP 2. The non-ventilated space 90 is a space in which the wind speed is slower than that of the ventilated space. The non-ventilation space 90 is, for example, a space through which air blown out from the indoor fan 28 does not pass as it is (without hitting any obstacle).

The non-air-permeable space 90 is preferably a space in which the air speed is 0.5 m/sec or less when the air conditioner 100 is operating. In other words, the non-ventilated space 90 is a space that: when the indoor fan 28 is operated, particularly, even when the indoor fan 28 is operated at the maximum air flow rate, the air speed in the air conditioner 100 is 0.5 m/sec or less in the non-ventilation space 90. More preferably, the non-air-space 90 is a space in which the wind speed (particularly, even when the indoor fan 28 is operated at the maximum wind volume) when the air conditioner 100 is operated is 0.25 m/sec or less. More preferably, the non-air-space 90 is a space in which the wind speed (particularly, even when the indoor fan 28 is operated at the maximum wind volume) is 0.15 m/sec or less when the air conditioner 100 is operated.

Further, the non-ventilated space 90 is preferably a space: in the non-air-flow space 90, the wind speed when the indoor fan 28 has the maximum wind volume is equal to or less than 1/5 of the wind speed of the air-flow space through which the air blown by the indoor fan 28 passes when the indoor fan 28 has the maximum wind volume. For example, the non-ventilated space 90 is a space: in the non-air-flow space 90, the average wind speed when the indoor fan 28 has the maximum wind volume is equal to or less than 1/5 of the average wind speed of the air-flow space through which the air blown by the indoor fan 28 passes when the indoor fan 28 has the maximum wind volume.

In the present embodiment, the non-ventilation space 90 is formed by a wind shielding member 92 inside the casing 30. The wind shielding member 92 is disposed on the downstream side of the indoor fan 28 and on the upstream side of the connection portion 21a and the connection portion 22a in the air blowing direction (the flow direction of the indoor air flow AF) of the indoor fan 28 (see fig. 4). The wind shielding member 92 forms the non-ventilation space 90 in which the connection portion 21a and the connection portion 22a are disposed on the downstream side of the wind shielding member 92. That is, the air blown out from the indoor fan 28 does not directly collide at least with the connection portion 21a and the connection portion 22a disposed in the non-ventilation space 90.

For example, in the present embodiment, the wind shielding member 92 includes two

flat plates

921, 922 extending downward from the top plate 31a of the housing 30 to the vicinity of the upper surface of the bottom plate 31c and intersecting with each other. The plate 921 extends rightward from the left side wall 31b, and the plate 922 extends rearward from the right end of the plate 921 to the rear side wall 31 b. The length of the

flat plates

921, 922 in the vertical direction and the length in the horizontal direction may be determined appropriately so that the air blown out from the indoor fan 28 does not directly hit at least the connection portion 21a and the connection portion 22 a.

The

flat plates

921, 922 may be made of metal or resin. The material of the wind shielding member 92 is not limited to metal or resin, and may be selected as appropriate.

Further, it is preferable that the condensation preventing member 98 for preventing condensation be provided around the connection portion 21a and the connection portion 22a, the condensation preventing member 98 be, for example, a condensation preventing cylinder formed in a hollow cylindrical shape, the condensation preventing member 98 be attached to the pipes (the gas refrigerant pipe 21, the gas refrigerant communication pipe GP, the liquid refrigerant pipe 22, and the liquid refrigerant communication pipe L P) so as to cover the connection portion 21a and the connection portion 22a (see fig. 5), the material of the condensation preventing member 98 is not limited, and, for example, rock wool or polystyrene foam may be used.

(3) Flow of refrigerant in air conditioner

In the air conditioner, when the cooling operation and the heating operation are performed, the refrigerant circulates through the refrigerant circuit RC in the manner described below.

(3-1) during Cooling operation

During the cooling operation, the flow direction switching mechanism 12 is in the state shown by the solid line in fig. 1, and the discharge side of the compressor 11 communicates with the gas side of the outdoor heat exchanger 13, and the suction side of the compressor 11 communicates with the gas side of the indoor heat exchanger 25.

In the above state, when the compressor 11 is driven, the low-pressure gas refrigerant is compressed in the compressor 11 to become a high-pressure gas refrigerant, the high-pressure gas refrigerant is sent to the outdoor heat exchanger 13 via the discharge pipe 16b, the flow direction switching mechanism 12, and the first gas refrigerant pipe 16c, then, the high-pressure gas refrigerant is heat-exchanged with outdoor air in the outdoor heat exchanger 13 and condensed to become a high-pressure liquid refrigerant (super-cooled liquid refrigerant), the high-pressure liquid refrigerant flowing out of the outdoor heat exchanger 13 is sent to the expansion mechanism 14, the low-pressure refrigerant decompressed in the expansion mechanism 14 flows through the liquid refrigerant pipe 16d, the liquid refrigerant communication pipe L P, and the liquid refrigerant pipe 22, flows into the indoor heat exchanger 25, the refrigerant flowing into the indoor heat exchanger 25 is heat-exchanged with indoor air to be evaporated to become a gas refrigerant (super-heated gas state), and flows out of the indoor heat exchanger 25, and the refrigerant flowing out of the indoor heat exchanger 25 flows through the gas refrigerant pipe 21, the gas refrigerant communication pipe GP, the second gas refrigerant pipe 16e, and the suction pipe 16a to be sucked into the compressor 11 again.

(3-2) heating operation

During the heating operation, the flow direction switching mechanism 12 is in a state shown by a broken line in fig. 1, and the discharge side of the compressor 11 communicates with the gas side of the indoor heat exchanger 25, and the suction side of the compressor 11 communicates with the gas side of the outdoor heat exchanger 13.

In the above state, when the compressor 11 is driven, the low-pressure gas refrigerant is compressed by the compressor 11 to become a high-pressure gas refrigerant, and is sent to the indoor heat exchanger 25 via the discharge pipe 16b, the flow direction switching mechanism 12, the second gas refrigerant pipe 16e, the gas refrigerant communication pipe GP, and the gas refrigerant pipe 21, the gas refrigerant in a high-pressure superheated state sent to the indoor heat exchanger 25 exchanges heat with the indoor air to be condensed into a high-pressure liquid refrigerant (a supercooled liquid refrigerant), and then flows out of the indoor heat exchanger 25, the refrigerant flowing out of the indoor heat exchanger 25 is sent to the expansion mechanism 14 via the liquid refrigerant pipe 22, the liquid refrigerant communication pipe L P, and the liquid refrigerant pipe 16d, the high-pressure liquid refrigerant sent to the expansion mechanism 14 is decompressed according to the valve opening degree of the expansion mechanism 14 when passing through the expansion mechanism 14, flows into the outdoor heat exchanger 13 via the low-pressure refrigerant of the expansion mechanism 14, the low-pressure refrigerant flowing into the outdoor heat exchanger 13 exchanges heat with the outdoor air to be evaporated into a low-pressure gas refrigerant, and is again flowed into the first gas refrigerant pipe 16c, the flow direction switching mechanism.

(4) Feature(s)

(4-1)

The air conditioner 100 of the present embodiment includes an outdoor unit 10 as an example of a heat source-side unit, an indoor unit 20 as an example of a usage-side unit, a gas refrigerant communication tube GP as a refrigerant communication tube, and a liquid refrigerant communication tube L P, the outdoor unit 10 has an outdoor heat exchanger 13 as an example of a heat source-side heat exchanger, the indoor unit 20 has an indoor heat exchanger 25 as an example of a usage-side heat exchanger, an indoor fan 28 as an example of a usage-side fan that supplies air to the indoor heat exchanger 25, the gas refrigerant communication tube GP and the liquid refrigerant communication tube L P connect the outdoor unit 10 and the indoor unit 20, the air conditioner 100 circulates refrigerant in a refrigerant circuit RC including the outdoor heat exchanger 13, the indoor heat exchanger 25, the gas refrigerant communication tube GP, and the liquid refrigerant communication tube L P to condition air in an air-conditioned space in which the indoor unit 20 is disposed, the refrigerant circuit RC includes a first tube made of a metal material, a second tube made of a metal material different from the metal material of the first tube, a second tube made of a metal material from the metal material of the first tube, a refrigerant circuit RC, and a refrigerant connection portion 22 made of the metal material of the metal refrigerant gas refrigerant communication tube 21, and liquid refrigerant connection portion 22a refrigerant connection portion of the metal material of the metal refrigerant communication tube 21a refrigerant communication tube 21, and the liquid refrigerant connection portion 22a refrigerant connection portion 22 made of the metal material of the metal refrigerant communication tube 21a refrigerant connection portion 22.

In the present air conditioner 100, the dissimilar

metal connection portions

21a and 22a are disposed in the non-air-permeable space 90. Therefore, in the present air conditioner 100, condensed water is less likely to be generated at the

connection portions

21a and 22a, and electrolytic corrosion at the

connection portions

21a and 22a is more likely to be suppressed.

(4-2)

In the air conditioner 100 of the present embodiment, the indoor unit 20 has a casing 30. The casing 30 accommodates the indoor heat exchanger 25 and the indoor fan 28. The air conditioner 100 includes a wind shielding member 92 forming a non-ventilation space 90 in the casing 30. The

connection portions

21a and 22a are disposed in the non-ventilation space 90 formed in the housing 30 by the wind shielding member 92.

Here, since the non-ventilation space 90 is formed in the casing 30 by the wind shielding member 92, the

connection portions

21a and 22a can be arranged even in the casing 30 in which the flow of air is likely to occur due to the presence of the indoor fan 28.

(4-3)

In the air conditioner 100 of the present embodiment, the wind shielding member 92 is disposed on the downstream side of the indoor fan 28 and on the upstream side of the

connection portions

21a and 22a in the air blowing direction (the flow direction of the indoor air flow AF) of the indoor fan 28. The wind shielding member 92 forms the non-ventilation space 90 in which the

connection portions

21a, 22a are arranged on the downstream side of the wind shielding member 92 in the air blowing direction of the indoor fan 28.

Here, the presence of the wind shielding member 92 suppresses the air blown out from the indoor fan 28 from colliding against the

connection portions

21a and 22 a. Therefore, electrolytic corrosion at the

connection portions

21a, 22a can be suppressed.

(4-4)

The air conditioner 100 of the present embodiment includes the condensation preventing member 98 which is disposed around the connecting

portions

21a and 22a and is different from the wind shielding member 92.

Here, the

connection portions

21a and 22a are disposed in the non-air-flow space 90 in the housing 30 formed by the wind shielding member 92, and the dew condensation preventing member 98 is provided around the

connection portions

21a and 22a, so electrolytic corrosion at the

connection portions

21a and 22a is particularly easily suppressed.

(4-5)

In the air conditioner 100 of the present embodiment, the non-air-space 90 is a space in which the wind speed is 0.5 m/sec or less when the air conditioner 100 is operating.

Here, since the wind speed in the non-air-space 90 is 0.5 m/sec or less even when the air conditioner 100 is operating, electrolytic corrosion at the

connection portions

21a, 22a can be suppressed.

More preferably, the non-air-space 90 is a space in which the air speed is 0.25 m/sec or less when the air conditioner 100 is operating. More preferably, the non-air-space 90 is a space in which the wind speed is 0.15 m/sec or less when the air conditioner 100 is operating.

(4-6)

In the air conditioner 100 of the present embodiment, the non-ventilation space 90 is a space: in the non-air-flow space 90, the wind speed when the indoor fan 28 has the maximum airflow rate is 1/5 or less of the wind speed in the air-flow space (the suction flow path FP1 and the outlet flow path FP2) through which the air blown by the indoor fan 28 passes when the indoor fan 28 has the maximum airflow rate. For example, the non-ventilated space 90 is a space: in the non-air-flow space 90, the average wind speed when the indoor fan 28 has the maximum wind volume is 1/5 or less of the average wind speed in the air-flow space (suction flow path FP1 and outlet flow path FP2) through which the air blown by the indoor fan 28 passes when the indoor fan 28 has the maximum wind volume.

Here, since the non-air-flow space 90 is a space in which the wind speed when the indoor fan 28 has the maximum wind volume is equal to or less than 1/5 of the wind speed in the air-flow space, electrolytic corrosion at the

connection portions

21a and 22a can be suppressed.

(4-7)

In the air conditioner 100 of the present embodiment, the gas refrigerant tube 21 and the liquid refrigerant tube 22, which are examples of the first pipe, are made of aluminum or an aluminum alloy, and the gas refrigerant communication tube GP and the liquid refrigerant communication tube L P, which are examples of the second pipe, are made of copper or a copper alloy.

Here, electrolytic corrosion of the connection portion between the aluminum/aluminum alloy pipe and the copper/copper alloy pipe at the

connection portions

21a and 22a can be suppressed.

(4-8)

In the air conditioner 100 of the present embodiment, the indoor unit 20 is a ceiling-mounted unit that is mounted on the ceiling of the air-conditioned space.

(5) Modification example

The above embodiment can be modified as appropriate as described in the modification examples below. Each modification may be combined with other modifications to the extent that no contradiction occurs.

(5-1) modification A

In the above embodiment, the connection portion 21a and the connection portion 22a are the connection portion between the gas refrigerant pipe 21 and the gas refrigerant communication tube GP and the connection portion between the liquid refrigerant pipe 22 and the liquid refrigerant communication tube L P, respectively, which are connected at the installation site of the air conditioner 100, but the present invention is not limited thereto.

For example, the connection portion 21a and the connection portion 22a may be a connection portion of a first pipe connected at one end to the indoor heat exchanger 25 in the indoor unit 20 and a second pipe connected to the first pipe at the side opposite to the side connected to the indoor heat exchanger 25 and made of copper or a copper alloy, and the connection portion of the second pipe and the refrigerant communication pipe GP or L P may be connected to the second pipe made of copper or a copper alloy, for example, and the connection portion of the second pipe and the refrigerant communication pipe GP or L P may not be disposed in the non-ventilation space.

(5-2) modification B

In the above embodiment, the non-ventilation space 90 and the ventilation spaces (the suction flow path FP1 and the outlet flow path FP2) are substantially separated by the wind shielding member 92, but the present invention is not limited thereto.

For example, a portion where the heat exchange portion 40 is not disposed exists in the rear left portion of the indoor heat exchanger 25 (see fig. 4). As shown in fig. 6 and 7, a wind shielding member 92a (flat plate) extending from the top plate 31a of the casing 30 to the vicinity of the bottom plate 31c may be provided at this portion, so that the non-ventilation space 90 is formed in such a manner that the air blown out by the indoor fan 28 does not directly collide with the connecting portion 21a and the connecting portion 22 a. In this case, the non-ventilation space 90 can be formed with a simple structure, although the wind speed in the non-ventilation space 90 may be increased, as compared with the case where the ventilation space (the suction flow path FP1 and the blow-out flow path FP2) and the non-ventilation space 90 are isolated by the wind shielding member 92.

(5-3) modification C

In the above embodiment, the

flat plates

921, 922 of the wind shielding member 92 are attached to the housing 30 or the like to form the non-ventilation space 90, but the present invention is not limited thereto.

For example, instead of attaching the wind shielding member to the housing 30, a cover member 96, which is an example of the wind shielding member, may be attached to the

pipes

21, 22, GP, L P, and the periphery of the

connection portions

21a, 22a is covered with the cover member 96, thereby forming the non-ventilation space 90 (see fig. 8) inside the cover member 96, the cover member 96 may be a rectangular parallelepiped or cylindrical case, for example, having a hollow portion in which the

connection portions

21a, 22a are disposed, the cover member 96 may be provided separately for the

connection portions

21a and 22a, or the cover member 96 may be provided in common for the

connection portions

21a and 22a, the cover member 96 may be made of a metal such as aluminum, an aluminum alloy, copper, or a copper alloy, which is less likely to cause electrolytic corrosion, or may be made of a resin, or the cover member 96 may be made of a material appropriately selected, and it is preferable that the dew condensation preventing member is disposed inside the cover member 96.

(5-4) modification example D

In the above embodiment, the non-ventilation space 90 is formed by the

flat plates

921, 922 of the wind shielding member 92, but is not limited thereto.

For example, the wind shielding member forming the non-ventilation space 90 may be a guide member that changes the wind direction by guiding the indoor air flow AF. The guide member may be disposed downstream of the indoor fan 28 and upstream of the

connection portions

21a and 22a in the air blowing direction of the indoor fan 28.

The wind shielding member forming the non-ventilation space 90 may be a mesh member having a large ventilation resistance, or the like, instead of being formed of a plate-shaped member having no holes.

(5-5) modification E

In the above embodiment, the non-ventilation space 90 is formed inside the casing 30, but as shown in fig. 9, a non-ventilation space 94 may be formed outside the casing 30. In fig. 9, the gas refrigerant tube 21 and the liquid refrigerant tube 22 are drawn out of the housing 30 from the opening 30a of the housing 30, and the

connection portions

21a and 22a are disposed outside the housing 30.

Since the air blown by the indoor fan 28 is blocked by the side wall 31b outside the casing 30, the wind speed is slower outside the casing 30 than in the ventilation space inside the casing 30. In this way, by disposing the

connection portions

21a and 22a outside the housing 30, the

connection portions

21a and 22a can be easily disposed in the non-ventilation space 94.

(5-6) modification F

Although not particularly mentioned in the above embodiment, the outdoor heat exchanger 13 may be a heat exchanger made of aluminum or an aluminum alloy including a plurality of flat perforated tubes and a plurality of fins. The outdoor unit 10 may have a connection portion of a dissimilar metal between a pipe made of aluminum or aluminum alloy extending from the outdoor heat exchanger 13 and a pipe made of copper or copper alloy.

In this case, it is preferable that the connection portions of different metals of the outdoor unit 10 are also disposed in the non-ventilation space in the same manner as the

connection portions

21a and 22a described in the above embodiment. The embodiment and the modification example have been described as examples of the configuration in which the connection portion of the dissimilar metal is disposed in the non-air-permeable space, and therefore, the description thereof is omitted here.

(5-7) modification G

In the above embodiment, the

connection portions

21a and 22a are portions where pipes made of aluminum or an aluminum alloy are connected to pipes made of copper or a copper alloy, but the present invention is not limited thereto. The combination of dissimilar metals disposed at the connection portion of the non-ventilation space may be any combination of metals that may cause electrolytic corrosion.

(5-8) modification example H

In the above embodiment, the indoor heat exchanger 25 is disposed so as to surround the indoor fan 28. However, the indoor heat exchanger 25 is not necessarily arranged so as to surround the indoor fan 28, and the shape and arrangement thereof may be appropriately changed as long as heat exchange between the indoor air flow AF and the refrigerant is possible.

(5-9) modification I

In the above embodiment, the air conditioner 100 having the ceiling-embedded indoor unit 20 has been described as an example, but the indoor unit of the air conditioner is not limited to the ceiling-embedded indoor unit.

For example, the indoor unit of the air conditioner may be another ceiling-mounted type indoor unit, for example, a ceiling-suspended type indoor unit fixed to the ceiling surface C L.

Further, the indoor unit of the air conditioner may be various types of indoor units other than a wall type, a duct type, a floor type, and a ceiling type, which are provided to a sidewall. The indoor unit may be of a type that blows air in all directions, as in the indoor unit 20 of the above-described embodiment, and may blow air in two directions or one direction, for example.

In addition, in the case where the indoor fan of the indoor unit is, for example, an indoor fan that blows air in one direction, the non-ventilation space may be formed on the side opposite to the blowing direction of the indoor fan or on the side of the indoor fan. With this configuration, the connection portion of the dissimilar metal can be disposed in the non-ventilation space without using a wind shielding member.

(5-10) modification J

In the above embodiment, the air conditioner 100 is a device capable of both cooling operation and heating operation. However, the present invention is not limited to this, and the refrigeration apparatus of the present disclosure may be an air-conditioning apparatus that performs only one of a heating operation and a cooling operation.

While the embodiments and the modifications have been described above, it should be understood that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

(availability in industry)

The present disclosure is widely applicable to air conditioners having a connection portion for connecting different types of metal pipes, and is advantageous.

Description of the symbols

10 outdoor unit (heat source side unit);

13 an outdoor heat exchanger (heat source side heat exchanger);

20 indoor units (utilization-side units);

21a gas refrigerant pipe (first pipe);

21a connecting part;

22a liquid refrigerant pipe (first pipe);

22a connecting part;

25 indoor heat exchangers (use side heat exchangers);

28 indoor fans (using side fans);

30a housing;

90. 94 non-ventilated space;

92. 92a wind shielding member;

96 cover members (wind shielding members);

98 a dew condensation preventing member;

100 air conditioners;

a GP gas refrigerant pipe (second pipe);

l P liquid refrigerant communication tube (second tube);

an RC refrigerant circuit.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open No. 2012-184870.

Claims

1. An air conditioner (100) that includes a heat source-side unit (10) having a heat source-side heat exchanger (13), a usage-side unit (20) having a usage-side heat exchanger (25) and a usage-side fan (28) that supplies air to the usage-side heat exchanger, and a refrigerant communication pipe (GP, L P) that connects the heat source-side unit and the usage-side unit, and that performs air conditioning of an air-conditioning target space in which the usage-side unit is disposed by circulating refrigerant in a Refrigerant Circuit (RC) that includes the heat source-side heat exchanger, the usage-side heat exchanger, and the refrigerant communication pipe,

the refrigerant circuit includes first pipes (21, 22) made of a metal material, second pipes (GP, L P) made of a metal material different from the metal material of the first pipes, and connection portions (21a, 22a) between the first pipes and the second pipes,

the connecting portion is disposed in a non-ventilation space (90, 94).

2. The air conditioner according to claim 1,

the usage-side unit further has a casing (30) that houses the usage-side heat exchanger and the usage-side fan,

the air conditioner further includes a wind shielding member (92, 92a, 96) forming the non-ventilation space inside the casing,

the connecting portion is disposed in the non-ventilation space (90) formed in the housing by the wind shielding member.

3. An air conditioner according to claim 2,

the wind shielding member is disposed downstream of the usage-side fan and upstream of the connection portion in an air blowing direction of the usage-side fan, and the non-ventilation space in which the connection portion is disposed is formed downstream of the wind shielding member.

4. An air conditioner according to claim 2 or 3,

the air conditioner further includes a dew condensation prevention member (98) which is disposed around the connection portion and is different from the wind shielding member.

5. The air conditioner according to claim 1,

the air conditioner further includes a cover member (96) that covers the periphery of the connection portion and forms the non-ventilation space inside.

6. The air conditioner according to claim 1,

the first pipe is a pipe provided in the usage-side unit,

the connecting part is arranged outside the shell.

7. An air conditioner according to any one of claims 1 to 6,

the non-ventilation space is a space in which the air speed is 0.5 m/sec or less when the air conditioner is in operation.

8. An air conditioner according to any one of claims 1 to 6,

the non-ventilated space is a space: the wind speed of the non-air-space when the usage-side fan has a maximum air volume is 1/5 or less of the wind speed of the air-space through which the air blown by the usage-side fan passes when the usage-side fan has the maximum air volume.

9. An air conditioner according to any one of claims 1 to 8,

one of the metal material of the first pipe and the metal material of the second pipe is aluminum or an aluminum alloy, and the other is copper or a copper alloy.

10. An air conditioner according to any one of claims 1 to 9,

the utilization-side unit is a ceiling-mounted unit (20) that is mounted on the ceiling of the space to be air-conditioned.