JP6673318B2 - air conditioner - Google Patents

Description

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

  2. Description of the Related Art Conventionally, different types of metal connection portions to which different types of metal pipes are connected may be provided in a refrigerant circuit of an air conditioner. Electrolytic corrosion may occur between dissimilar metals due to the difference in metal ionization tendency. In particular, when dew condensation occurs in pipes and water droplets containing metal ions of one metal come into contact with pipes of the other metal material, electrolytic corrosion of the pipes tends to be a problem.

  To cope with such a problem, Patent Document 1 (Japanese Patent Application Laid-Open No. 2012-184870) describes that a U-shaped portion or an inverted U-shaped portion for suppressing the movement of dew water or the like is provided in a pipe.

  However, Patent Document 1 (Japanese Patent Application Laid-Open No. 2012-184870) does not describe suppressing dew condensation at a dissimilar metal connection portion.

  An object of the present disclosure is to provide an air conditioner in which condensed water is less likely to be generated at a connection portion to which different types of metal pipes are connected, and electric erosion at the connection portion is easily suppressed.

  The air conditioner includes a heat source side unit, a use side unit, and a refrigerant communication pipe. The heat source side unit has a heat source side heat exchanger. The use-side unit has 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 use side unit. The air conditioner circulates a refrigerant in a refrigerant circuit including a heat source side heat exchanger, a use side heat exchanger, and a refrigerant communication pipe to perform air conditioning of a space to be air conditioned where the use side unit is arranged. The refrigerant circuit includes a first pipe made of a metal material, a second pipe made of a metal material different from the first pipe, and a connection portion between the first pipe and the second pipe. The connection portion is disposed in the non-ventilated space.

  In the present air conditioner, the connection part of the dissimilar metal is arranged in the non-ventilated space. Therefore, in the present air conditioner, condensed water is less likely to be generated at the connection portion, and electric erosion at the connection portion is easily suppressed.

  Preferably, in the air conditioner, the use side unit further includes a casing. The casing houses the use side heat exchanger and the use side fan. The air conditioner further includes a wind shield member forming a non-ventilated space in the casing. The connection portion is disposed in a non-ventilated space formed in the casing by the wind shielding member.

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

  Preferably, in the air conditioner, the wind shield member is disposed downstream of the use-side fan and upstream of the connection portion in a direction in which the use-side fan blows air. The wind shield member forms a non-ventilation space in which a connection portion is disposed downstream of the wind shield member in the direction in which the use-side fan blows air.

  Here, due to the presence of the wind shielding member, the air blown out from the usage-side fan is prevented from hitting the connection portion. Therefore, it is possible to suppress electrolytic corrosion at the connection portion.

  Preferably, the air conditioner further includes a dew condensation preventing member that is arranged around the connection portion and is different from the wind shielding member.

  Here, the connection portion is disposed in the non-ventilated space in the casing formed by the wind shielding member, and the dew condensation preventing member is provided around the connection portion, so that electrolytic corrosion at the connection portion is particularly easily suppressed.

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

  Here, by forming a non-ventilated 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 included in the use side unit. The use side unit further has a casing. The casing houses the use side heat exchanger and the use side fan. The connection is arranged outside the casing.

  Here, since the use side fan is housed and the connection portion is arranged outside the casing in which the air flow is generated, the connection portion can be easily arranged in the non-ventilated space.

  Preferably, in the air conditioner, the non-ventilated space is a space where the wind speed during operation of the air conditioner is 0.5 m / sec or less.

  Here, since the wind speed in the non-ventilated space is 0.5 m / sec or less even during the operation of the air conditioner, it is possible to suppress the electrolytic corrosion at the connection portion.

  Preferably, in the air conditioner, the non-ventilated space has a wind speed when the use side fan is set to the maximum air volume, which is one of the wind speeds of the ventilation space through which the air blown out by the use side fan when the use side fan is set to the maximum air volume. / 5 or less space.

  Here, the non-ventilated space is a space where the wind speed is equal to or less than 1/5 of the wind speed of the ventilated space when the use side fan is set to the maximum air volume.

  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, it is possible to suppress the electrolytic corrosion of the connecting portion between the aluminum / aluminum alloy piping and the copper / copper alloy piping at the connecting portion.

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

It is a schematic structure figure of an air conditioner concerning one embodiment. It is a perspective view of the indoor unit of the air conditioner of FIG. FIG. 3 is a schematic cross-sectional view of the indoor unit mounted on a ceiling, as viewed in the direction of arrows III-III in FIG. 2. FIG. 3 is a bottom view schematically illustrating a schematic configuration of the indoor unit in FIG. 2. FIG. 4 illustrates the indoor unit with the decorative panel removed. FIG. 5 is a schematic sectional view taken along the line VV in FIG. 4. FIG. 11 is a bottom view schematically illustrating a schematic configuration of an indoor unit of Modification Example B. FIG. 6 illustrates the indoor unit with the decorative panel removed. It is a perspective view of the indoor heat exchanger of FIG. FIG. 14 is a bottom view schematically showing a schematic configuration of an indoor unit of Modification C. FIG. 8 illustrates the indoor unit with the decorative panel removed. It is a bottom view which showed typically the schematic structure of the indoor unit of the modification E. FIG. 9 illustrates the indoor unit with the decorative panel removed.

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

  In the following embodiments, expressions such as up, down, left, right, front, and back may be used to describe directions and positional relationships, but the directions indicated by these expressions are indicated by arrows in the drawings. Follow the directions indicated by.

(1) Overall Overview FIG. 1 is a schematic configuration diagram of an air conditioner 100.

  The air conditioner 100 is a device that performs a cooling operation or a heating operation to perform air conditioning in a target space. Specifically, the air conditioner 100 has 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 use side unit, and a gas as an example of a refrigerant communication pipe connecting the outdoor unit 10 and the indoor unit 20. A refrigerant communication pipe GP and a liquid refrigerant communication pipe LP.

  The gas refrigerant communication pipe GP and the liquid refrigerant communication pipe LP are pipes laid at the installation site of the air conditioner 100. The pipe diameter and the pipe length of the gas refrigerant communication pipe GP and the liquid refrigerant communication pipe LP are individually selected according to design specifications and installation environment. In the present embodiment, the gas refrigerant communication pipe GP and the liquid refrigerant communication pipe LP 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 communication pipe GP and the liquid refrigerant communication pipe LP, so that the refrigerant circuit RC is configured. The refrigerant circuit RC includes an outdoor heat exchanger 13 described below of the outdoor unit 10, an indoor heat exchanger 25 described below of the indoor unit 20, a gas refrigerant communication pipe GP and a liquid refrigerant communication pipe LP. The air conditioner 100 circulates a refrigerant in the refrigerant circuit RC to perform air conditioning of a space to be air-conditioned in which the indoor unit 20 is arranged.

  The refrigerant circuit RC is filled with, for example, an HFC refrigerant such as R32 or R410A. However, the type of the refrigerant is not limited to R32 or R410A, and may be HFO1234yf, HFO1234ze (E), a mixed refrigerant thereof, or the like.

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

  Specifically, the refrigerant circuit RC includes a gas refrigerant pipe 21 of an indoor unit 20 made of aluminum or an aluminum alloy, a gas refrigerant communication pipe GP made of copper or a copper alloy, a gas refrigerant pipe 21 and a gas refrigerant communication pipe GP. Connection portion 21a. The refrigerant circuit RC includes a liquid refrigerant pipe 22 of the indoor unit 20 made of aluminum or an aluminum alloy, a liquid refrigerant communication pipe LP made of copper or a copper alloy, and a connection part between the liquid refrigerant pipe 22 and the liquid refrigerant communication pipe LP. 22a. Since the connection part 21a and the connection part 22a are connection parts of dissimilar metals, electrolytic corrosion is likely to occur. Therefore, the connection part 21a and the connection part 22a are arranged in a non-ventilated space to suppress electric erosion due to condensed water. The details will be described later.

  Hereinafter, the outdoor unit 10, the indoor unit 20, and the connection portions 21a and 22a will be described in detail.

(2) Detailed Configuration (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 has 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 16 a 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 16 c 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 LP. 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, compresses, and discharges a low-pressure gas refrigerant. The compressor 11 is an inverter-controlled compressor capable of adjusting the number of rotations of the motor (capable of adjusting the capacity). The number of revolutions of the compressor 11 is adjusted by a control unit (not shown) according to the operating conditions. Note that the compressor 11 may be a compressor in which the number of rotations of a 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 switching valve.

  In the cooling operation mode, the flow direction switching mechanism 12 switches the flow direction of the refrigerant in the refrigerant circuit RC so 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 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 so 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 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 switching valve, and may be configured to combine a plurality of solenoid valves and refrigerant pipes to realize the above-described switching of 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 refrigerant condenser during the cooling operation and functions as an evaporator of the refrigerant during the heating operation. The outdoor heat exchanger 13 has 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 that decompresses the high-pressure refrigerant that flows in. In the present embodiment, the expansion mechanism 14 is an electric valve whose opening 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 a motor-operated valve, but may be a capillary tube or the like.

(2-1-5) Outdoor Fan The outdoor fan 15 is a blower that generates an airflow that flows into the outdoor unit 10 from the outside, passes through the outdoor heat exchanger 13, and flows out of the outdoor unit 10. During operation, the driving of the outdoor fan 15 is controlled by a control unit (not shown), and the number of revolutions is appropriately adjusted.

(2-2) Indoor Unit FIG. 2 is a perspective view of the indoor unit 20. FIG. 3 is a schematic cross-sectional view of the indoor unit 20 attached to the ceiling surface CL as viewed in the direction of arrows III-III in FIG. 2. FIG. 4 is a schematic diagram showing a schematic configuration of the indoor unit 20 as viewed from below.

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

(2-2-1) Casing The casing 30 is a housing that accommodates various components of the indoor unit 20. The casing 30 mainly accommodates the indoor heat exchanger 25 and the indoor fan 28 (see FIG. 3).

  As shown in FIG. 3, the casing 30 is inserted into an opening formed in the ceiling surface CL of the target space, and is inserted into the ceiling space CS formed between the ceiling surface CL and the upper floor or the roof. Will be installed. The casing 30 includes a top plate 31a, side walls 31b, a bottom plate 31c, and a decorative panel 32 (see FIGS. 2 and 3).

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

  The side wall 31b is a member constituting a side surface portion of the casing 30, and has a substantially octagonal prism shape corresponding to the shape of the top plate 31a. An opening 30a for inserting (pulling) the gas refrigerant communication pipe GP and the liquid refrigerant communication pipe LP into the casing 30 is formed in the side wall 31b (see FIG. 4). In the present embodiment, the gas refrigerant communication pipe GP and the liquid refrigerant communication pipe LP are inserted from the opening 30a of the side wall 31b, and the gas refrigerant communication pipe GP and the gas refrigerant pipe 21 are connected in the casing 30, and the liquid refrigerant communication pipe is connected. The LP and the liquid refrigerant pipe 22 are connected. That is, in the present embodiment, the connection portion 21a and the connection portion 22a are arranged in the casing 30.

  The bottom plate 31c is a member that constitutes a bottom surface portion of the casing 30, and has a substantially square large opening 311 formed in the center (see FIG. 3). A plurality of openings 312 are formed around the large opening 311 of the bottom plate 31c (see FIGS. 3 and 4). A decorative panel 32 is attached to the lower surface side (target space side) of the bottom plate 31c (see FIGS. 2 and 3).

  The decorative panel 32 is a plate-shaped member exposed to the target space, and has a substantially square shape in plan view. The decorative panel 32 is fitted and installed in the opening of the ceiling surface CL (see FIG. 3). The decorative panel 32 is formed with an air inlet 33 and a plurality of outlets 34. The suction port 33 is formed in a substantially quadrangular shape in a central portion of the decorative panel 32 at a position partially overlapping with the large opening 311 of the bottom plate 31c in plan view. The plurality of outlets 34 are formed around the inlet 33 so as to surround the inlet 33. Each outlet 34 is arranged at a position corresponding to the opening 312 of the bottom plate 31c. The air sucked in from the inlet 33, passed through the indoor heat exchanger 25, and blown out from each opening 312 is blown out from the 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 entirety of the indoor heat exchanger 25 (including a heat exchange unit 40 described later and a header pipe to which the gas refrigerant pipe 21 and the liquid refrigerant pipe 22 are connected) is made of aluminum or an aluminum alloy. One end of a gas refrigerant pipe 21 and one end of a liquid refrigerant pipe 22 made of aluminum or an aluminum alloy are connected to the indoor heat exchanger 25.

  The indoor heat exchanger 25 has a plurality of rows (here, two rows) of heat exchange units 40 in which a plurality of flat multi-hole tubes 45 are vertically arranged and stacked. The rows of the heat exchange units 40 are arranged along an indoor air flow AF generated by an indoor fan 28 described later (see FIG. 5). Each heat exchange section 40 mainly includes a plurality of flat multi-hole tubes 45 and a plurality of heat transfer fins 48 (see FIG. 5).

  The cross section of the flat multi-hole tube 45 has a flat shape. A plurality of refrigerant channels (flat tube channels 451) extending along the direction in which the flat multi-hole tube 45 extends are formed inside the flat multi-hole tube 45 (see FIG. 5). The plurality of flat pipe flow paths 451 are arranged in the flat multi-hole pipe 45 so as to be arranged in the direction of the indoor airflow AF (see FIG. 5).

  The heat transfer fins 48 are plate-shaped members that increase the heat transfer area between the flat multi-hole tube 45 and the indoor airflow AF. The heat transfer fins 48 are made of aluminum or an aluminum alloy. Each heat transfer fin 48 extends so as to intersect the flat multi-hole tube 45 with the lamination direction (vertical direction) of the flat multi-hole tube 45 as a longitudinal direction. A plurality of slits 48a are formed in the heat transfer fins 48 at intervals along the vertical direction. A flat multi-hole tube 45 is inserted into each slit 48a (see FIG. 5). In each heat exchange section 40, a plurality of heat transfer fins 48 are arranged at intervals along the extending direction of the flat multi-hole tube 45.

  The indoor heat exchanger 25 (heat exchange section 40) is bent at about 90 degrees at three places in a plan view, and is arranged in a substantially quadrilateral shape (see FIG. 3). The indoor heat exchanger 25 is arranged so as to surround the inlet 33 and to be surrounded by the outlet 34 in plan view. In other words, the indoor heat exchanger 25 is formed in a substantially rectangular shape. The indoor heat exchanger 25 is arranged 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 pipe flow path 451 exchanges heat with the air passing from the inside to the outside of the indoor heat exchanger 25, and the liquid refrigerant pipe Outflow from 22. When the refrigerant flows from the liquid refrigerant pipe 22 into the indoor heat exchanger 25, the refrigerant flowing through the flat tube flow path 451 exchanges heat with air passing from the inside to the outside of the indoor heat exchanger 25, and It flows out of the refrigerant pipe 21.

(2-2-3) Indoor Fan The indoor fan 28 is an example of a usage-side fan. The indoor fan 28 supplies air to the indoor heat exchanger 25 which is an example of the use side heat exchanger.

  The indoor fan 28 generates an airflow (indoor airflow AF, see FIG. 5 and the like) flowing into the indoor unit 20 from outside the casing 30, passing through the indoor heat exchanger 25, and flowing out of the indoor unit 20. It is a blower. During operation, the driving of the indoor fan 28 is controlled by a control unit (not shown), and the rotation speed is appropriately adjusted.

  Inside the casing 30, an indoor fan 28 is arranged at a central portion, and an indoor heat exchanger 25 is arranged so as to surround the indoor fan 28. The indoor fan 28 partially overlaps with the suction port 33 in a plan view (see FIG. 4).

  In the casing 30, a suction flow path FP <b> 1 for guiding the indoor airflow AF flowing into the casing 30 through the suction port 33 to the indoor heat exchanger 25, and the indoor airflow passing through the indoor heat exchanger 25. An outlet channel FP2 for sending the AF to the outlet port 34 is formed (see FIG. 3). The outlet channel FP2 is disposed outside the inlet channel FP1 so as to surround the inlet channel FP1. The suction channel FP1 and the outlet channel FP2 are examples of a ventilation space.

  In the above-described manner, the suction port 33, the air outlet 34, the suction flow path FP1, and the discharge flow path FP2, the indoor heat exchanger 25, and the indoor fan 28 are arranged, so that the indoor fan 28 is operated during the indoor operation. In the unit 20, the indoor airflow AF flows through the following route.

  The indoor airflow AF generated by the indoor fan 28 flows into the casing 30 through the suction port 33. The indoor airflow AF blown out from the indoor fan 28 is radially blown out from the indoor fan 28 (see FIG. 4) as viewed from below, and is guided to the indoor heat exchanger 25 via the suction flow path FP1. The indoor airflow AF guided to the indoor heat exchanger 25 exchanges heat with the refrigerant in the indoor heat exchanger 25, and is then sent to the outlet 34 through the outlet flow path FP2, and is sent from the outlet 34. It is blown out to the target space.

(2-3) Connection Portion The connection portion 21a is a connection portion between the gas refrigerant pipe 21 of the indoor unit 20 as an example of the first pipe and the gas refrigerant communication pipe GP as an example of the second pipe. The gas refrigerant pipe 21 is a pipe made of aluminum or an aluminum alloy as described above. The gas refrigerant communication pipe GP is a pipe made of copper or a copper alloy as described above.

  The connection part 21a is a connection part of a dissimilar metal. In the present embodiment, the gas refrigerant pipe 21 and the gas refrigerant communication pipe GP are joined by brazing using a brazing material. Note that the brazing connection is merely an example of a method of connecting the gas refrigerant pipe 21 and the gas refrigerant communication pipe GP. For connection between the gas refrigerant pipe 21 and the gas refrigerant communication pipe GP, for example, a connection method such as a friction welding method or a eutectic welding method may be used. Further, for the connection between the gas refrigerant pipe 21 and the gas refrigerant communication pipe GP, a connection method that satisfies the design specifications (for example, a required connection strength can be ensured) is appropriately selected even if a method other than the illustrated method is used. I just need.

  The connection part 22a is a connection part between the liquid refrigerant pipe 22 of the indoor unit 20 as an example of the first pipe and the liquid refrigerant communication pipe LP as an example of the second pipe. The liquid refrigerant pipe 22 is a pipe made of aluminum or an aluminum alloy as described above. The liquid refrigerant communication pipe LP is a pipe made of copper or a copper alloy as described above. The connection part 22a is also a connection part of a dissimilar metal. The connection method between the liquid refrigerant pipe 22 and the liquid refrigerant communication pipe LP at the connection part 22a may be the same as the connection method of the connection part 21a.

  The connection part 21a and the connection part 22a are arranged in the non-ventilated space 90 in order to suppress the generation of condensed water in the connection part 21a and the connection part 22a to prevent electrolytic corrosion.

  In particular, in the present embodiment, the connection portion 21a and the connection portion 22a are arranged in the non-ventilated space 90 formed in the casing 30. The non-ventilation space 90 is a space in the casing 30 other than the ventilation space including the inside of the suction passage FP1 and the inside of the blowout passage FP2. The non-ventilation space 90 is a space having a lower wind speed than the ventilation space. The non-ventilation space 90 is, for example, a space through which air blown from the indoor fan 28 does not pass as it is (does not pass without hitting any obstacle).

  The non-ventilation space 90 is preferably a space in which the air velocity during operation of the air conditioner 100 is 0.5 m / sec or less. In other words, the non-ventilation space 90 is a space in which the air speed of the air conditioner 100 is 0.5 m / sec or less even when the indoor fan 28 is operated, particularly when the indoor fan 28 is operated at the maximum air volume. It is. More preferably, it is a space where the wind speed during the operation of the air conditioner 100 is 0.25 m / sec or less (especially even when the indoor fan 28 is operated at the maximum air volume). More preferably, the space is such that the wind speed during operation of the air conditioner 100 is 0.15 m / sec or less (especially even when the indoor fan 28 is operated at the maximum air volume).

  The non-ventilation space 90 preferably has a wind speed when the indoor fan 28 is at the maximum air volume, which is 1/5 of a wind speed at which the air blown by the indoor fan 28 passes when the indoor fan 28 is at the maximum air volume. The following space. For example, in the non-ventilated space 90, the average wind speed when the indoor fan 28 is set to the maximum air volume is 1/5 or less of the average wind speed in the ventilation space through which the air blown out by the indoor fan 28 when the indoor fan 28 is set to the maximum air volume. Space.

  In the present embodiment, the non-ventilated space 90 is formed by a wind shielding member 92 inside the casing 30. The wind shield member 92 is disposed downstream of the indoor fan 28 and upstream of the connection portions 21a and 22a in the direction in which the indoor fan 28 blows air (the flow direction of the indoor airflow AF) (see FIG. 4). . The wind shield member 92 forms a non-ventilated space 90 in which the connection portions 21a and 22a are arranged downstream of the wind shield member 92. That is, at least the air blown out from the indoor fan 28 does not directly hit the connecting portion 21a and the connecting portion 22a arranged in the non-ventilated space 90.

  For example, in the present embodiment, the wind shield member 92 includes two flat plates 921 and 922 that extend downward from the top plate 31a of the casing 30 to near the upper surface of the bottom plate 31c. The flat plate 921 extends rightward from the left side wall 31b, and the flat plate 922 extends rearward from the right end of the flat plate 921 to the rear side wall 31b. Note that the vertical length and the horizontal length of the flat plates 921 and 922 may be appropriately determined so that the air blown out from the indoor fan 28 does not directly hit the connecting portions 21a and 22a at least.

  The flat plates 921 and 922 may be made of metal or resin. Further, the material of the wind shield member 92 is not limited to metal or resin, and may be appropriately selected.

  Further, it is preferable that a dew condensation preventing member 98 for preventing dew condensation is provided around the connection part 21a and the connection part 22a. The dew condensation preventing member 98 is, for example, a dew-proof cylinder formed in a hollow cylindrical shape. The dew condensation preventing member 98 is attached to pipes (the gas refrigerant pipe 21, the gas refrigerant communication pipe GP, the liquid refrigerant pipe 22, and the liquid refrigerant communication pipe LP) so as to cover the connection part 21a and the connection part 22a (see FIG. 5). Although the material of the dew condensation preventing member 98 is not limited, for example, rock wool or polystyrene foam is used.

(3) Flow of Refrigerant in Air Conditioner In the air conditioner, during the cooling operation and the heating operation, the refrigerant circulates in the refrigerant circuit RC as described below.

(3-1) At the time of cooling operation At the time of cooling operation, the flow direction switching mechanism 12 is in the state shown by the solid line in FIG. 1, the discharge side of the compressor 11 communicates with the gas side of the outdoor heat exchanger 13, and Communicates with the gas side of the indoor heat exchanger 25.

  When the compressor 11 is driven in such a state, the low-pressure gas refrigerant is compressed by 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. The high-pressure gas refrigerant exchanges heat with outdoor air in the outdoor heat exchanger 13 to condense into a high-pressure liquid refrigerant (supercooled 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 reduced in pressure in the expansion mechanism 14 flows through the liquid refrigerant pipe 16d, the liquid refrigerant communication pipe LP, and the liquid refrigerant pipe 22, and flows into the indoor heat exchanger 25. The refrigerant that has flowed into the indoor heat exchanger 25 evaporates by performing heat exchange with the indoor air to become a low-pressure gas refrigerant (a superheated gas refrigerant) and flows out of the indoor heat exchanger 25. 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, and is sucked into the compressor 11 again.

(3-2) At the time of heating operation At the time of heating operation, the flow direction switching mechanism 12 is in the state shown by the broken line in FIG. 1, the discharge side of the compressor 11 communicates with the gas side of the indoor heat exchanger 25, and the compressor 11 Communicates with the gas side of the outdoor heat exchanger 13.

  When the compressor 11 is driven in such a state, the low-pressure gas refrigerant is compressed by the compressor 11 to become a high-pressure gas refrigerant, and the discharge pipe 16b, the flow direction switching mechanism 12, the second gas refrigerant pipe 16e, The refrigerant is sent to the indoor heat exchanger 25 via the refrigerant communication pipe GP and the gas refrigerant pipe 21. The high-pressure superheated gas refrigerant sent to the indoor heat exchanger 25 is condensed by performing heat exchange with indoor air to become a high-pressure liquid refrigerant (supercooled liquid refrigerant), and then indoor heat exchange. It flows out of the vessel 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 LP, and the liquid refrigerant pipe 16d. The high-pressure liquid refrigerant sent to the expansion mechanism 14 is reduced in pressure according to the valve opening of the expansion mechanism 14 when passing through the expansion mechanism 14. The low-pressure refrigerant that has passed through the expansion mechanism 14 flows into the outdoor heat exchanger 13. The low-pressure refrigerant flowing into the outdoor heat exchanger 13 exchanges heat with outdoor air and evaporates to a low-pressure gas refrigerant, which is compressed via the first gas refrigerant pipe 16c, the flow direction switching mechanism 12, and the suction pipe 16a. It is sucked into the machine 11 again.

(4) Features (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 use side unit, a gas refrigerant communication pipe GP and a liquid refrigerant communication pipe LP as a refrigerant communication pipe. , Is provided. The outdoor unit 10 has an outdoor heat exchanger 13 as an example of a heat source side heat exchanger. The indoor unit 20 includes an indoor heat exchanger 25 as an example of a use side heat exchanger, and an indoor fan 28 as an example of a use side fan that supplies air to the indoor heat exchanger 25. The gas refrigerant communication pipe GP and the liquid refrigerant communication pipe LP connect the outdoor unit 10 and the indoor unit 20. The air conditioner 100 circulates refrigerant in a refrigerant circuit RC including an outdoor heat exchanger 13, an indoor heat exchanger 25, a gas refrigerant communication pipe GP and a liquid refrigerant communication pipe LP, and the indoor unit 20 is disposed. Perform air conditioning of the air-conditioned space. The refrigerant circuit RC includes a first pipe made of a metal material, a second pipe made of a metal material different from the first pipe, and a connection portion between the first pipe and the second pipe. In the present embodiment, the refrigerant circuit RC includes a gas refrigerant pipe 21 made of a metal material, a gas refrigerant communication pipe GP made of a metal material different from the gas refrigerant pipe 21, a gas refrigerant pipe 21, and a gas refrigerant communication pipe GP. And a connection portion 21a. The refrigerant circuit RC includes a liquid refrigerant pipe 22 made of a metal material, a liquid refrigerant communication pipe LP made of a metal material different from the liquid refrigerant pipe 22, and a connection between the liquid refrigerant pipe 22 and the liquid refrigerant communication pipe LP. A part 22a. The connection portions 21 a and 22 a are arranged in the non-ventilated space 90.

  In the present air conditioner 100, connection portions 21 a and 22 a of different metals are arranged in the non-ventilated 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 electric erosion at the connection portions 21a and 22a is easily suppressed.

(4-2)
In the air conditioner 100 of the present embodiment, the indoor unit 20 has the casing 30. The casing 30 houses the indoor heat exchanger 25 and the indoor fan 28. The air conditioner 100 includes a wind shielding member 92 that forms a non-ventilated space 90 in the casing 30. The connection portions 21 a and 22 a are arranged in a non-ventilation space 90 formed in the casing 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 are arranged even in the casing 30 where the flow of air is likely to occur due to the presence of the indoor fan 28. Can be.

(4-3)
In the air conditioner 100 of the present embodiment, the wind shield member 92 is located 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 flow direction of the indoor air flow AF). Be placed. The wind shield member 92 forms a non-ventilated space 90 in which the connecting portions 21 a and 22 a are arranged downstream of the wind shield member 92 in the direction in which the indoor fan 28 blows air.

  Here, the presence of the wind shield member 92 suppresses the air blown from the indoor fan 28 from hitting the connection portions 21a and 22a. Therefore, it is possible to suppress electrolytic corrosion in the connection portions 21a and 22a.

(4-4)
The air conditioner 100 of the present embodiment includes a dew condensation preventing member 98 that is arranged around the connection portions 21a and 22a and is different from the wind shield member 92.

  Here, the connection portions 21a and 22a are arranged in the non-ventilated space 90 in the casing 30 formed by the wind shielding member 92, and the dew condensation preventing member 98 is provided around the connection portions 21a and 22a. Electrolytic corrosion at 21a and 22a is particularly likely to be suppressed.

(4-5)
In the air conditioner 100 of the present embodiment, the non-ventilated space 90 is a space where the wind speed during operation of the air conditioner 100 is 0.5 m / sec or less.

  Here, since the wind speed in the non-ventilated space 90 is 0.5 m / sec or less even during the operation of the air conditioner 100, it is possible to suppress electrolytic corrosion in the connection portions 21a and 22a.

  In addition, more preferably, the non-ventilation space 90 is a space in which the wind speed during operation of the air conditioner 100 is 0.25 m / sec or less. More preferably, the non-ventilation space 90 is a space in which the air velocity during operation of the air conditioner 100 is 0.15 m / sec or less.

(4-6)
In the air conditioner 100 of the present embodiment, the non-ventilation space 90 is a ventilation space through which air blown by the indoor fan 28 when the indoor fan 28 has the maximum air volume passes when the indoor fan 28 has the maximum air volume. This is a space that is equal to or less than 1/5 of the wind speed of the suction flow path FP1 and the blow flow path FP2). For example, the non-ventilation space 90 has an average wind speed when the indoor fan 28 is at the maximum air volume, and a ventilation space (the suction flow path FP1 and the air outlet) through which the air blown by the indoor fan 28 when the indoor fan 28 is at the maximum air volume passes. The space is equal to or less than 1/5 of the average wind speed of the flow path FP2).

  Here, when the indoor fan 28 is set to the maximum air volume, the non-ventilated space 90 is a space whose wind speed is equal to or less than 1/5 of the wind speed of the ventilated space.

(4-7)
In the air conditioner 100 of the present embodiment, the gas refrigerant pipe 21 and the liquid refrigerant pipe 22 as an example of the first pipe are made of aluminum or an aluminum alloy, and the gas refrigerant communication pipe GP and the liquid refrigerant as an example of the second pipe. The connecting pipe LP is made of copper or a copper alloy.

  Here, in the connection parts 21a and 22a, the electrolytic corrosion of the connection part between the pipe made of aluminum / aluminum alloy and the pipe made of copper / copper alloy 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 installed on a ceiling of a space to be air-conditioned.

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

(5-1) Modification A
In the above-described embodiment, the connection portion 21a and the connection portion 22a are respectively connected to the gas refrigerant pipe 21 and the gas refrigerant communication pipe GP, and the liquid refrigerant pipe 22 are connected at the installation site of the air conditioner 100. And the connection part between the liquid refrigerant communication pipe LP and the connection part, but the invention is not limited to this.

  For example, the connection part 21a and the connection part 22a are connected in a factory or the like, and a first pipe made of aluminum or an aluminum alloy, one end of which is connected to the indoor heat exchanger 25 in the indoor unit 20; It may be a connection portion with a second pipe made of copper or a copper alloy connected to the side opposite to the side connected to the heat exchanger 25. In such a configuration, at the installation site of the air conditioner 100, for example, the copper or copper alloy refrigerant communication pipes GP and LP may be connected to the copper or copper alloy second pipe. The connection between the pipe and the refrigerant communication pipes GP and LP need not be arranged in the non-ventilated space.

(5-2) Modification B
In the above embodiment, the non-ventilation space 90 is generally isolated from the ventilation space (the suction passage FP1 and the blowout passage FP2) by the wind shielding member 92, but is not limited to this.

  For example, in the indoor heat exchanger 25, there is a portion where the heat exchange section 40 is not disposed at the rear left portion (see FIG. 4). In this part, as shown in FIGS. 6 and 7, a wind shield member 92a (flat plate) extending from the top plate 31a of the casing 30 to the vicinity of the bottom plate 31c is provided, and the air blown out by the indoor fan 28 is applied to the connection portions 21a and 22a. The non-ventilation space 90 may be formed so as not to hit directly. In this case, the wind speed of the non-ventilation space 90 may increase as compared with the case where the ventilation space (the suction passage FP1 and the outlet passage FP2) and the non-ventilation space 90 are separated by the wind shielding member 92. The non-ventilation space 90 can be formed with a simple structure.

(5-3) Modification C
In the above-described embodiment, the non-ventilated space 90 is formed by attaching the flat plates 921 and 922 of the wind shield member 92 to the casing 30 or the like. However, the present invention is not limited to this.

  For example, instead of attaching a wind shield member to the casing 30, a cover member 96, which is an example of a wind shield member, is attached to the pipes 21, 22, GP, LP, and the cover member 96 covers the periphery of the connection portions 21a, 22a, and A non-ventilation space 90 may be formed inside the member 96 (see FIG. 8). The cover member 96 is, for example, a rectangular parallelepiped or columnar housing having a hollow portion in which the connecting portions 21a and 22a are arranged. The cover member 96 may be provided for each of the connection part 21a and the connection part 22a, or may be common to the connection part 21a and the connection part 22a. The cover member 96 may be made of aluminum or an aluminum alloy, a metal which is unlikely to cause electrolytic corrosion with copper or a copper alloy, or may be made of a resin or the like. In addition, the material of the cover member 96 may be appropriately selected. It is preferable that a dew condensation preventing member is disposed inside the cover member 96.

(5-4) Modification D
In the above embodiment, the non-ventilation space 90 is formed by the flat plates 921 and 922 of the wind shielding member 92, but the invention is not limited to this.

  For example, the wind shield member forming the non-ventilated space 90 may be a guide member that guides the indoor airflow AF to change the wind direction. Such a guide member may not be disposed downstream of the indoor fan 28 and upstream of the connection portions 21a and 22a in the direction in which the indoor fan 28 blows air.

  Further, the wind shield member forming the non-ventilation space 90 may be a mesh member or the like having a large ventilation resistance, instead of a plate member having no holes.

(5-5) Modification E
In the above embodiment, the non-ventilated space 90 is formed inside the casing 30. However, as shown in FIG. 9, a non-ventilated space 94 may be formed outside the casing 30. In FIG. 9, the gas refrigerant pipe 21 and the liquid refrigerant pipe 22 are drawn out of the casing 30 from the opening 30 a of the casing 30, and the connection portions 21 a and 22 a are arranged outside the casing 30.

  Outside the casing 30, the air blown out by the indoor fan 28 is blocked by the side wall 31 b, so that the wind speed outside the casing 30 is lower than that of the ventilation space inside the casing 30. By arranging the connection portions 21a and 22a outside the casing 30, the connection portions 21a and 22a can be easily arranged in the non-ventilated space 94.

(5-6) Modification F
Although not particularly mentioned in the above embodiment, the outdoor heat exchanger 13 may be an aluminum or aluminum alloy heat exchanger including a plurality of flat multi-hole tubes and a plurality of fins. And the outdoor unit 10 may have a connection part of a different metal between a pipe made of aluminum or an aluminum alloy extending from the outdoor heat exchanger 13 and a pipe made of copper or a copper alloy.

  In such a case, it is preferable that the connection part of the different kind of metal of the outdoor unit 10 is also arranged in the non-ventilated space similarly to the connection parts 21a and 22a described in the above embodiment. The manner of arranging the connection parts of different kinds of metals in the non-ventilated space has already been exemplified in the above-described embodiment and modified examples, and thus the description is omitted here.

(5-7) Modification G
In the above embodiment, the connection portions 21a and 22a are portions where a pipe made of aluminum or an aluminum alloy is connected to a pipe made of copper or a copper alloy, but is not limited to this. The combination of dissimilar metals in the connection portion arranged in the non-ventilated space may be any combination of metals that may cause electrolytic corrosion.

(5-8) Modification H
In the above embodiment, the indoor heat exchanger 25 is arranged so as to surround the indoor fan 28. However, the indoor heat exchanger 25 does not necessarily need to be arranged so as to surround the indoor fan 28, and its shape and arrangement may be changed as appropriate as long as the indoor air flow AF and the refrigerant can exchange heat. Is possible.

(5-9) Modification I
In the above embodiment, the air conditioner 100 having the indoor unit 20 embedded in the ceiling has been described as an example, but the indoor unit of the air conditioner is not limited to the indoor unit embedded in the ceiling.

  For example, the indoor unit of the air conditioner may be another indoor unit of a ceiling installation type, for example, an indoor unit of a ceiling hanging type fixed to a ceiling surface CL.

  Further, the indoor unit of the air conditioner may be various types of indoor units other than the ceiling-mounted type, such as a wall-mounted type, a duct-type, and a floor-mounted type, which are installed on a side wall. The indoor unit may be of a type that blows air in all directions like the indoor unit 20 of the above embodiment, or may be an indoor unit that blows air in two directions or one direction, for example.

  When the indoor fan of the indoor unit is, for example, an indoor fan that blows air in one direction, the non-ventilated space is formed on the side opposite to the blowing direction of the indoor fan or on the side of the indoor fan. You may. With this configuration, it is possible to arrange the connection portion of the dissimilar metal in the non-ventilated space without using the wind shielding member.

(5-10) Modification J
In the above embodiment, the air conditioner 100 is a device that can execute both the cooling operation and the heating operation. However, the present invention is not limited to this, and the refrigeration apparatus of the present disclosure may be an air conditioner that performs only one of the heating operation and the cooling operation.

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

  INDUSTRIAL APPLICABILITY The present disclosure is widely applicable and useful for an air conditioner having a connection portion to which different types of metal pipes are connected.

10. Outdoor unit (heat source side unit)
13. Outdoor heat exchanger (heat source side heat exchanger)
20 indoor unit (user side unit)
21 Gas refrigerant pipe (first pipe)
21a Connection part 22 Liquid refrigerant pipe (first pipe)
22a Connection part 25 Indoor heat exchanger (use side heat exchanger)
28 Indoor fan (user side fan)
30 casing 90, 94 non-ventilated space 92, 92a wind-insulating member 96 cover member (wind-insulating member)
98 Dew condensation prevention member 100 Air conditioner GP Gas refrigerant communication pipe (second pipe)
LP liquid refrigerant communication pipe (second pipe)
RC refrigerant circuit

JP 2012-184870 A

Claims (8)

A heat source side unit (10) having a heat source side heat exchanger (13); a use side unit (25) having a use side heat exchanger (25) and a use side fan (28) for supplying air to the use side heat exchanger. 20), and a refrigerant communication pipe (GP, LP) connecting the heat source side unit and the usage side unit, wherein the heat source side heat exchanger, the usage side heat exchanger, and the refrigerant communication pipe are connected to each other. An air conditioner that circulates a refrigerant in a refrigerant circuit (RC) including the air conditioner and air-conditions a space to be air-conditioned where the use side unit is arranged,
The refrigerant circuit includes a first pipe (21, 22) made of a metal material, a second pipe (GP, LP) made of a metal material different from the first pipe, the first pipe and the first pipe. Connection part (21a, 22a) with two pipes,
The first pipe is a pipe included in the use side unit,
The use side unit further includes a casing (30) that houses the use side heat exchanger and the use side fan,
The connection portion is disposed outside the casing,
Air conditioner (100). A heat source side unit (10) having a heat source side heat exchanger (13); a use side unit (25) having a use side heat exchanger (25) and a use side fan (28) for supplying air to the use side heat exchanger. 20), and a refrigerant communication pipe (GP, LP) connecting the heat source side unit and the usage side unit, wherein the heat source side heat exchanger, the usage side heat exchanger, and the refrigerant communication pipe are connected to each other. An air conditioner that circulates a refrigerant in a refrigerant circuit (RC) including the air conditioner and air-conditions a space to be air-conditioned where the use side unit is arranged,
The refrigerant circuit includes a first pipe (21, 22) made of a metal material, a second pipe (GP, LP) made of a metal material different from the first pipe, the first pipe and the first pipe. Connection part (21a, 22a) with two pipes,
The connection portion is disposed in a non-ventilated space (90, 94);
The use side unit further includes a casing (30) that houses the use side heat exchanger and the use side fan,
The air conditioner further includes a wind shield member (92, 92a, 96) that forms the non-ventilated space in the casing.
The connection portion is disposed in the non-ventilated space (90) formed in the casing by the wind shielding member ,
The wind shielding member is formed of at least one plate-like member,
air conditioner. The wind shield member is disposed downstream of the use fan and upstream of the connection portion in the air blowing direction of the use side fan, and the connection portion is disposed downstream of the wind shield member. Forming the non-ventilated space,
The air conditioner according to claim 2. The air conditioner further includes a dew condensation preventing member (98) arranged around the connection portion and different from the wind shielding member.
The air conditioner according to claim 2. The non-ventilated space is a space in which the wind speed during operation of the air conditioner is 0.5 m / sec or less.
The air conditioner according to any one of claims 2 to 4 . In the non-ventilation space, the wind speed when the use-side fan has the maximum air volume is 1/5 of the wind speed of the ventilation space through which the air blown out by the use-side fan passes when the use-side fan has the maximum air volume. The following space,
The air conditioner according to any one of claims 2 to 4 . 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.
The air conditioner according to any one of claims 1 to 6 . The usage-side unit is a ceiling-mounted unit (20) installed on a ceiling of the air-conditioned space.
The air conditioner according to any one of claims 1 to 7 .

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