JP2017145978A - Outdoor machine of air conditioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an outdoor machine of an air conditioner capable of surely suppressing corrosion of a heat transfer pipe for a long period.SOLUTION: An outdoor machine 1 of an air conditioner 100 includes: a plurality of tabular fins 5 aligned in a plate thickness direction; a plurality of heat transfer pipes 6 provided in a multistage manner in a longitudinal direction of the fin 5 so as to penetrate the fins 5; and a heat exchanger 4 configured to fluidize refrigerant inside the plurality of heat transfer pipes 6, and perform heat exchange between the refrigerant and air. In at least one or more heat transfer pipes 6 containing a lower most heat transfer pipe 61 among the heat transfer pipes 6, the refrigerant does not flow.SELECTED DRAWING: Figure 3

Description

  The present invention relates to an outdoor unit of an air conditioner.

  Conventionally, a heat exchanger of an air conditioner includes an aluminum alloy or copper heat transfer tube and aluminum alloy fins. The heat exchanger is arrange | positioned on the base in the outdoor unit of an air conditioner. The base of the outdoor unit is generally made of a hot-dip plated steel sheet that has been surface-treated with a zinc alloy or the like.

In the outdoor unit having such a configuration, the following problems may occur when the base and the heat exchanger are in contact with each other.
The base may be exposed by corrosion of the zinc alloy plating layer of the base due to corrosion caused by rain water, condensed water from heat exchangers, and splashing caustic substances such as chlorides and sulfides. In this case, the dissimilar metal contact corrosion occurs when the steel plate base and the aluminum alloy fin are in electrical contact with each other through an electrolyte solution such as water. When corrosion of the aluminum alloy due to this different metal contact corrosion proceeds rapidly, there is a problem that the heat exchange efficiency of the heat exchanger is lowered.

  Also, if the fin disappears due to the progress of corrosion and the heat transfer tube is exposed, the rust of the base steel that scatters adheres, dissimilar metal contact corrosion occurs, and the corrosion of the tube wall proceeds rapidly . In this case, there is a problem that refrigerant leakage is likely to occur due to the thin tube thickness of the heat transfer tube.

  As a means for preventing such dissimilar metal contact corrosion, an insulating material is sandwiched between the heat exchanger and the bottom plate, or a base metal and a base metal that is electrically lower than aluminum are used. An outdoor unit that suppresses corrosion of fins and pipes by arranging a configured spacer is known (see, for example, Patent Documents 1 and 2).

Japanese Patent No. 5401585 Japanese Patent No. 4479207

However, in the spacer having a drainage channel installed between the bottom plate and the heat exchanger described in Patent Document 1, the drainage channel is clogged with dust, a scale contained in flowing water, etc. when used over a long period of time. There was a problem that the sex deteriorated.
In this case, in the outdoor unit, corrosion-causing substances remain, and there is a possibility that dissimilar metal contact corrosion occurs between the corroded base scattering pieces, the fins, and the heat transfer tubes.

  In addition, the outdoor unit described in Patent Document 2 uses a spacer made of a metal that is electrically baser than aluminum, so that when the spacer is preferentially corroded, the outdoor unit does not play the role of supporting the heat exchanger. There was a point. In this case, since the outdoor unit cannot obtain the sacrificial anticorrosive effect in the portions other than the spacer, there is a possibility that the heat exchanger is deformed or the heat transfer tube is broken.

  Therefore, the present invention provides an outdoor unit for an air conditioner that can reliably suppress corrosion of a heat transfer tube over a long period of time with respect to the above problems.

  In order to solve the above problems, an outdoor unit of an air conditioner according to the present invention is provided with a plurality of plate-like fins arranged in the plate thickness direction and a plurality of stages in the longitudinal direction of the fins through the fins. A plurality of heat transfer tubes, a heat exchanger for causing the refrigerant to flow inside the heat transfer tubes and exchanging heat between the air and the refrigerant, and being located at the lowest position among the heat transfer tubes. The refrigerant does not flow through at least one or more heat transfer tubes including the heat tubes.

  The outdoor unit of the air conditioner according to the present invention can reliably suppress corrosion of the heat transfer tube over a long period of time.

It is a block diagram which shows the structure of the refrigerating cycle of the air conditioner which concerns on embodiment of this invention. It is a disassembled perspective view which shows the structure of the outdoor unit of the air conditioner which concerns on embodiment of this invention. It is a schematic side view which shows the arrangement | positioning state of the heat exchanger tube of a heat exchanger. It is a principal part perspective view which shows the installation state of a heat exchanger. It is a principal part perspective view which shows the installation state of a hot gas path | route. It is a right view of a heat exchanger. It is a principal part enlarged plan view which shows the state of the distribution part of a heat exchanger. It is a principal part expanded bottom view of the heat exchanger which shows the installation state of a distribution part. It is a perspective view of the heat exchanger which shows a state when manufacturing two or more heat exchangers. It is a schematic side view of the heat exchanger which shows the 1st modification of an outdoor unit. It is a schematic side view of the heat exchanger which shows the 2nd modification of an outdoor unit. It is a schematic side view of the heat exchanger which shows the 3rd modification of an outdoor unit. It is a principal part schematic perspective view of the heat exchanger which shows the 4th modification of an outdoor unit. It is a perspective view of the heat exchanger shown.

Next, an example of an outdoor unit of an air conditioner according to an embodiment of the present invention will be described with reference to FIGS.
Hereinafter, in the drawings of the embodiments and in the first to fourth modified examples described later, when the same components are shown, the same symbols are added and the description thereof is omitted.
As shown in FIG. 2, the outdoor unit 1 of the air conditioner 100 includes a heat exchanger 4 having fins 5 and heat transfer tubes 6, and a housing 8 having a base 81 that supports the heat exchanger 4. If so, the structure, model, etc. are not particularly limited. In other words, the outdoor unit is provided with the blower 7 arranged in the horizontal direction in the housing 8, and even the outdoor unit 1 of a general household air conditioner that sends out the wind in the horizontal direction has the blower arranged in the upward direction. It may be an outdoor unit of a multi air conditioning apparatus for buildings that is provided on the body and sends the wind upward.

  Hereinafter, as an example of an embodiment of the present invention, the outdoor unit 1 of the air conditioner 100 that sends out wind in the lateral direction will be described as an example.

<Air conditioner>
As shown in FIG. 1, the air conditioner 100 includes an outdoor unit 1 that is disposed outside, and an indoor unit 2 that is connected to the outdoor unit 1 by pipes 91 and 92 and disposed indoors. ing. In the refrigeration cycle of the air conditioner, the outdoor unit 1 includes a compressor 3, a four-way valve V1, an outdoor heat exchanger 4, an outdoor fan 7, and an expansion valve V2. Yes.

<Outdoor unit>
As shown in FIG. 2, the outdoor unit 1 includes a heat exchanger 4 that performs heat exchange with outside air, a blower 7 that generates an air flow that promotes heat exchange of the heat exchanger 4, the blower 7, and heat exchange. And a housing 8 that supports the container 4. When the fan 72 of the blower 7 is rotated by the motor 71, the outdoor unit 1 sucks outside air outside the outdoor unit 1, performs heat exchange with the heat exchanger 4, and discharges it into the atmosphere. In other words, the outside air is sucked into the housing 8 from the outside of the housing 8 by the rotation of the fan 72, and is discharged from the air outlet 82 a to the atmosphere via the heat exchanger 4.

  In the outdoor unit 1 of the present invention, the refrigerant does not flow through at least one or more heat transfer tubes 6 including the heat transfer tube 61 positioned at the lowermost position among the heat transfer tubes 6 in which pipes extending in the horizontal direction are arranged in multiple stages in the vertical direction. A heat exchanger 4 is provided. The heat exchanger 4 and the heat transfer tube 6 will be described in detail later.

<Indoor unit>
As shown in FIG. 1, the indoor unit 2 is a device installed on an indoor wall surface, ceiling surface, or the like. The indoor unit 2 is disposed between a suction port provided in the indoor unit 2, an indoor heat exchanger 21 that exchanges heat with indoor air sucked from the suction port, and the suction port and the indoor heat exchanger 21. A filter, an indoor blower 22 (for example, a conventional fan) provided on the air path from the suction port to the air outlet, and a wind direction louver disposed at the air outlet are provided.

<Case>
As shown in FIG. 2, the housing 8 is a main body case of the outdoor unit 1 and is formed in, for example, a rectangular parallelepiped shape having a hollow inside. The housing 8 is erected on the base 81 provided on the lower surface of the housing 8, the front plate 82 erected on the front end portion on the base 81, and the left and right end portions and the left and right rear end portions of the base 81. It has side plates 83 and 84 and a top cover 85 provided on the top, and is formed in a rectangular shape in plan view. The housing 8 such as the base 81 is formed of a steel plate that is entirely coated with a corrosion-resistant paint and covered.

  As shown in FIG. 2, the base 81 is a bottom plate of the housing 8. On the base 81, the compressor 3, the heat exchanger 4, an electric box (not shown), a motor support member 86, and a pipe inner / outer connection member 87 (see FIG. 4) are mounted. Is supported from below (see FIG. 1). The base 81 has a bottom plate portion 81a having a bent portion that is bent upward in the peripheral portion, and leg portions 81b joined to the front, rear, left and right of the bottom surface of the bottom plate portion 81a.

  The front plate 82 is a plate member that forms the front surface of the housing 8. The front plate 82 is formed in a circular mesh shape and is formed with an air outlet 82a for blowing out air. A fan 72 of the blower 7 is disposed inside the air outlet 82a.

  The left and right side plates 83 and 84 are plate members that are bent in an L shape in plan view to form the left and right side surfaces of the housing 8 and the rear surface of the housing 8. The left and right side plates 83 and 84 are formed with a large number of suction ports 83 a for sucking and taking in outside air by the blower 7. Between the right side plate 83 and the left side plate 84, a rear opening 8a for sucking and taking in outside air by the blower 7 is formed. The heat exchanger 4 is provided on the inner wall side of the left and right side plates 83 and 84.

  The top cover 85 is an upper plate provided on the upper surface of the housing 8. The top cover 85 is horizontally provided at the upper end portions of the front plate 82, the side plates 83 and 84, and the motor support member 86.

  The motor support member 86 is a plate member for arranging the motor 71 at the center of the rear surface of the housing 8. The motor support member 86 is bent and reinforced so as to have a substantially concave cross-sectional shape, and supports the motor 71 at the center of a flat plate portion extending in the vertical direction. The motor support member 86 has an upper end fixed to the rear central portion of the top cover 85 and a lower end fixed to a position closer to the rear of the upper central portion of the base 81.

<Blower>
The blower 7 is a blowing means for blowing outside air sucked from the suction openings 83a of the side plates 83 and 84 and the rear opening 8a back to the outside through the heat exchanger 4. The blower 7 includes a motor 71 having a motor shaft 71a protruding in the forward direction, and a fan 72 connected to the tip of the motor shaft 71a.

  The motor 71 is an electric motor for driving the fan 72 to rotate. The motor 71 includes a motor shaft 71a, a motor case 71b arranged in a state in which the motor shaft 71a protrudes in the forward direction, a motor bracket 71c formed to protrude in the left-right direction from the lower end of the outer peripheral portion of the motor case 71b, It has.

  The fan 72 is composed of, for example, an axial flow type propeller fan to which the motor shaft 71a of the motor 71 is connected. The fan 72 is formed by integrally molding a cylindrical fan boss portion formed at the center portion and a blade portion protruding from the outer peripheral surface of the fan boss portion.

<Compressor>
The compressor 3 shown in FIG. 2 is a refrigerant flow means that, for example, sends a high-temperature and high-pressure refrigerant discharged from the compressor 3 to the outdoor heat exchanger 4 via the four-way valve V1 during the cooling operation. The compressor 3 is mounted on the base 81.

<Heat exchanger>
The heat exchanger 4 includes a plurality of plate-like fins 5 arranged in the plate thickness direction, and a plurality of heat transfer tubes 6 that penetrate the fins 5 and are provided in a plurality of stages in the longitudinal direction of the fins 5. Has been. The heat exchanger 4 is a device that exchanges heat between air and the refrigerant by causing the refrigerant to flow inside the plurality of heat transfer tubes 6 and blowing air in a direction perpendicular to the plate thickness direction of the fins 5. The heat exchanger 4 is placed on the base 81 and arranged in an L shape in plan view from the front end of the side plate 84 to the right side of the rear opening 8a. The heat exchanger 4 includes a heat transfer tube 61 in which at least one (for example, two) refrigerant does not flow, including the heat transfer tube 61 located at the lowest position among the heat transfer tubes 6.

<Fin>
As shown in FIG. 4, the fin 5 is formed by arranging a number of substantially strip-like plate members extending in the upward direction in the thickness direction. The fins 5 are configured, for example, by arranging a large number of aluminum alloy flat plate members arranged in the thickness direction at appropriate intervals in a substantially L shape in plan view.

<Heat transfer tube>
As shown in FIG. 3 or FIG. 4, the heat transfer tube 6 is composed of a number of tubes that pass through the fins 5 so as to be orthogonal to the fins 5 and through which the refrigerant flows. The heat transfer tube 6 is a dummy heat transfer tube 61 that is provided in the lower part (lower part) of the heat exchanger 4 and does not flow refrigerant, heat transfer tubes 62 to 65 that are arranged above the heat transfer tube 61 and flow refrigerant, It is configured with. The heat transfer tube 6 is connected via a cycle pipe 66 to a hot gas path 93 (see FIG. 1) extended from the inside / outside connection portion 11 of a pipe inside / outside connection member 87 erected on the base 81.

  The dummy heat transfer tube 61 is a spacer that is disposed above the dummy heat transfer tube 61 to protect the heat transfer tubes 62 to 65 through which the refrigerant flows from corrosion caused by frost, ice, rainwater, or the like. The heat transfer tube 61 includes a hollow cylindrical heat transfer tube main body 61a and lid portions 61b that close both side openings of the heat transfer tube main body 61a. The heat transfer pipe 61 is composed of one to three pipes that extend horizontally along the base 81 at the lower stage of the heat exchanger 4. Note that the number of the heat transfer tubes 61 through which the refrigerant does not flow may be at least one in the heat exchanger 4 and is most preferably one. That is, the heat transfer tube 6 can suppress the deterioration of the heat exchange function by setting the number of dummy heat transfer tubes 61 to the minimum number and increasing the number of heat transfer tubes 62 to 65 through which the refrigerant flows. .

  The heat transfer tube body 61a is made of, for example, piping made of aluminum or aluminum alloy. Even if the lid 61b is formed by crushing and closing the opening end of the heat transfer tube main body 61a, a cap-like lid member made of copper or copper alloy is formed on the opening end of the heat transfer tube main body 61a with silicon or the like. May be closed by brazing.

  The heat transfer tubes 62 to 65 through which the refrigerant flows are composed of a large number of U-shaped pipes arranged in parallel above the dummy heat transfer tubes 61 with appropriate intervals. The heat transfer tubes 62 to 65 include a hollow cylindrical heat transfer tube main body 62a, and a U-shaped tube 62b (hairpin pipe) that is arranged above and below and connects the openings of the two heat transfer tube main bodies 62a. . The heat transfer tubes 62 to 65 are connected by brazing a heat transfer tube main body 62a made of aluminum or aluminum alloy and a U-shaped tube 62b made of copper or copper alloy with phosphorus or copper. As shown in FIG. 4, a cycle pipe 66 is connected to the heat transfer tubes 62 and 65.

  As shown in FIGS. 6 to 8, the cycle pipe 66 has a heat exchanger such that the distribution part 66 a is arranged at a position spaced apart from the tube axis plane of the heat exchanger 4 by four times or more the width W of the fin 5. 4 is attached. For this reason, the distribution part 66a is spaced apart from the fin 5 in the left-right direction. For example, the width W of the fin 5 is about 12.7 mm. Moreover, the distance of the distribution part 66a from the pipe-axis plane of the heat exchanger 4 is about 50 mm, for example. The cycle pipe 66 is made of copper or a copper alloy pipe, and is brazed to the heat transfer pipe 62 with phosphorus or copper.

  Since the cycle pipes 66 are provided so as to protrude from the fins 5 in this way, the heat exchanger 4 can stack a plurality of cycles pipes 66 in a staggered direction at a time, as shown in FIG. The heat exchanger 4 can be manufactured.

  As shown in FIG. 4 or FIG. 5, the hot gas path 93 is a flow path for preventing freezing in which warm refrigerant flows. The hot gas path 93 is connected to the inside / outside connection portion 11 provided in the pipe inside / outside connection member 87 at the right end of the base 81. The hot gas path 93 is arranged to heat the entire front lower part and the entire rear lower part of the heat exchanger 4. The heat radiating portion of the hot gas path 93 is formed of copper or a copper alloy.

  The hot gas path 93 may be provided with a valve V3 (see FIG. 1) for sending the refrigerant to the vicinity of the base 81 only when it is desired to supply a warm refrigerant. In a cold region, the warm refrigerant may always flow without attaching the valve V3 to the hot gas path 93.

≪Action≫
Next, with reference to FIGS. 1-9, the effect | action of the outdoor unit of the air conditioner which concerns on embodiment of this invention is demonstrated.

  As shown in FIG. 2, in the outdoor unit 1 of the air conditioner 100, when the motor 71 is rotationally driven, the fan 72 is rotated via the motor shaft 71a. Then, the fan 72 sucks the outside air on the outer periphery of the outdoor unit 1 into the outdoor unit 1 from the rear opening 8a and the like, exchanges heat with the heat exchanger 4, and sends it forward from the outlet 82a. Release into the atmosphere. For this reason, the air sucked into the housing 8 by the fan 72 flows through the heat exchanger 4 and promotes heat exchange between the refrigerant and the air.

  As shown in FIG. 3, the heat exchanger 4 includes a heat transfer tube 61 including at least one (for example, two) refrigerants including a heat transfer tube 61 positioned at the lowermost position among the heat transfer tubes 6. Yes. Specifically, in the heat exchanger 4, a dummy heat transfer tube 61 that does not flow a refrigerant for preventing icing and improving corrosion resistance is located on the lower side of the lower heat transfer tubes 62 to 65 through which the refrigerant flows. Of the first stage and the second stage. For this reason, the two dummy heat transfer tubes 61 function as a spacer for taking an insulation distance between the heat transfer tube 62 through which the refrigerant flows and the base 81.

  As a result, even if frost or ice freezes on the upper surface of the base 81, the distance between the heat transfer tubes 62 to 65 through which the refrigerant flows and the base 81 can be secured so that they cannot be in contact with each other. Corrosion caused by contact with frost or ice on ˜65 and the base 81 can be suppressed. In this way, the heat transfer tubes 62 to 65 arranged separately above the base 81 via the dummy heat transfer tubes 61 are prevented from corroding over a long period of time, and therefore, the occurrence of holes due to corrosion is eliminated. Can do.

  Further, since the heat transfer tube 6 is made of aluminum or an aluminum alloy, the heat transfer tube 6 can be manufactured at a low weight and at a low cost, and the heat dissipation can be maintained well.

As shown in FIGS. 4 and 5, the upper surface of the base 81, the lower surface of the heat exchanger 4, the front side of the lower end portion, and the rear side of the lower end portion are provided with hot gas passages 93, so that the top of the base 81 is frozen. Or when frost adheres, it can be heated and melted to be vaporized. For this reason, it can arrange | position to a lower step part and can prevent that the heat exchanger tube 6 corrodes.
Moreover, the heat dissipation part of the hot gas path | route 93 can improve heat dissipation by being formed with copper or a copper alloy.

  As described above, the outdoor unit 1 according to the present invention is configured such that, in the heat exchanger 4, the refrigerant does not flow through at least one or more heat transfer tubes 6 including the heat transfer tube 61 positioned at the lowest position among the heat transfer tubes 6. Thus, a sufficient distance can be secured between the base 81 and the heat transfer tube 62 through which the lowermost refrigerant of the heat exchanger 4 flows. Further, even if there is frost, ice, rainwater, or the like on the base 81, it can be vaporized by the hot gas path 93 through which the warm refrigerant flows. For this reason, corrosion of the heat transfer tube 6 can be reliably suppressed over a long period of time.

[Modification]
As mentioned above, although this invention was demonstrated based on embodiment, this invention is not limited to the structure described in the said embodiment, Including suitably combining thru | or selecting the structure described in embodiment, The configuration can be changed as appropriate without departing from the spirit of the invention.

[First Modification]
FIG. 10 is a schematic side view of a heat exchanger showing a first modification of the outdoor unit.
In the embodiment, as an example of the heat exchanger 4 (see FIG. 3), one or more (two) heat transfer tubes 61 in which no refrigerant flows are inserted between the lower portion of the heat exchanger 4 and the base 81. However, the present invention is not limited to this. As shown in FIG. 10, the plurality of heat transfer tubes 6 </ b> A may be formed by thinning out the heat transfer tubes 61 </ b> A and 66 </ b> A arranged at the lowermost stage and the uppermost stage one by one.

  In this case, the outdoor unit causes the refrigerant to flow inside the plurality of heat transfer tubes 6A, and heat exchange is performed between the air and the refrigerant by blowing air in a direction perpendicular to the plate thickness direction of the fins 5A. And a base 81 that supports the heat exchanger 4A. The heat exchanger 4A includes a plurality of plate-like fins 5A arranged in the plate thickness direction, and a plurality of heat transfer tubes 6A that penetrate the fins 5A and are provided in a plurality of stages in the longitudinal direction of the fins 5A. . The heat transfer tubes 61A and 66A are formed by brazing cap-shaped lids 61Ab to both ends of a cylindrical pipe 61Aa.

  As described above, when the lowermost heat transfer tube 61A of the heat exchanger 4A and the uppermost heat transfer tube 66A are arranged one by one, a large number of heat transfer tubes arranged in the lateral direction are arranged. One dummy heat transfer tube 61A is arranged in each of the lowermost part 4Aa and the uppermost part 4Ab of 6A. That is, the heat transfer tubes 62A to 65A through which the refrigerant flows are not arranged at the positions of the lowermost part 4Aa and the uppermost part 4Ab of the heat exchanger 4A. For this reason, since the dummy heat transfer tube 61A is arranged in the installation space in which one heat transfer tube 6A can be installed between the base 81 and the lowermost heat transfer tube 62A through which the refrigerant flows, The heat pipe 61A serves as a spacer.

  Therefore, when frost or ice is generated on the base 81 in the cold season, the heat transfer tubes 62A to 65A through which the refrigerant flows have the frost or Since it arrange | positions in the state spaced apart from ice, corrosion by frost and ice can be prevented.

  The uppermost heat transfer tube 66A also has a dummy heat transfer tube between the top cover 85 and the uppermost heat transfer tube 65A through which the refrigerant flows, similarly to the heat transfer tube 61A, by thinning one heat transfer tube 6A. Since 66A is arranged, it plays the role of a spacer for taking an insulation distance. For this reason, since the uppermost heat transfer tube 66A also functions to prevent corrosion due to frost and ice in the same manner as the heat transfer tube 61A, it is possible to prevent a hole from being formed in the heat transfer tube 61A due to corrosion over a long period of time.

[Second Modification]
FIG. 11 is a schematic side view of a heat exchanger showing a second modification of the outdoor unit.
In addition, as shown in FIG. 11, the plurality of heat transfer tubes 6B of the heat exchanger of the outdoor unit may be provided with grooves 61Ba and 67Ba in the heat transfer tubes 61B and 67B arranged at the lowermost stage and the uppermost stage, respectively.

  In this case, the outdoor unit has a heat exchanger 4B that exchanges heat between air and the refrigerant by causing the refrigerant to flow inside the plurality of heat transfer tubes 6B and blowing air in a direction perpendicular to the plate thickness direction of the fins 5B. And a base 81 that supports the heat exchanger 4B. The heat exchanger 4B includes a plurality of plate-like fins 5B arranged in the plate thickness direction, and a plurality of heat transfer tubes 6B that penetrate the fins 5B and are provided in a plurality of stages in the longitudinal direction of the fins 5B. .

The lowermost heat transfer tube 61B and the uppermost heat transfer tube 61B include pipes extending in the lateral direction along the heat transfer tubes 62B to 66B.
The grooves 61Ba and 67Ba are, for example, concave grooves that are formed in a semicircular shape when viewed from the longitudinal section, which is formed by cutting the horizontally disposed heat transfer tube 6B into two vertically. The shape of the grooves 61Ba and 67Ba may be a groove shape, and may be, for example, an arc shape, a U-shaped groove shape, a V-shaped groove shape, a recessed groove shape, or the like.

In this way, grooves 61Ba and 67Ba are formed in the lowermost heat transfer tube 61B and the uppermost heat transfer tube 67B arranged in the lowermost part 4Ba and the uppermost part 4Bb of the heat exchanger 4B, respectively. For this reason, since the grooves 61Ba and 67Ba can reduce the surface that contacts the base 81 and the top cover 85, it is easy to allow rainwater or the like dropped on the fin 5B from the upper side to easily flow out of the grooves 61Ba and 67Ba. Can do.
As a result, the heat exchanger 4B suppresses the heat transfer tube 6B from corroding because the bottom heat transfer tube 61B and the uppermost heat transfer tube 67B have grooves 61Ba and 67Ba, which makes it difficult for water to collect. can do.

  Further, since the lowermost heat transfer tube 61B and the uppermost heat transfer tube 61B extend in the lateral direction along the other heat transfer tubes 62B to 66B, the lowermost heat transfer tube 62B and the base through which the refrigerant flows are provided. 81, and the same function as that in which a spacer for taking an insulation distance is arranged between the uppermost heat transfer tube 66 </ b> B through which the refrigerant flows and the top cover 85 (see FIG. 2).

[Third Modification]
FIG. 12 is a schematic side view of a heat exchanger showing a third modification of the outdoor unit.
In addition, as shown in FIG. 12, the heat exchanger may cause the refrigerant to flow to the heat transfer tube 61C that is initially arranged at the lowest stage during the defrost cycle operation by the reverse cycle.

In this case, the heat transfer tube 6 </ b> C is arranged in a multistage manner with a large number of lateral heat transfer tubes 61 </ b> C to 65 </ b> C through which a refrigerant flows, similarly to the heat transfer tubes of the heat exchanger of the conventional outdoor unit.
When the air conditioner 100 is operated in a defrost cycle, warm refrigerant flows from the distribution section (header) to the lowermost heat transfer pipe 61C in the heat transfer pipe 6C, and then in order, second from the lower side. The heat transfer pipe 62C flows from the lower side to the third heat transfer pipe 63C, and flows from the uppermost heat transfer pipe 65C to the downstream top.

  In this way, the heat exchanger 4C allows the warmest refrigerant to flow to the heat transfer tube 61C disposed first in the lowest stage during the defrost cycle operation (defrosting), so that the warmest refrigerant is The frost and ice can flow toward the position near the base 81. For this reason, even if frost or ice adheres to the base 81 in the cold season, the heat exchanger 4C efficiently flows frost by flowing a warm refrigerant from the lower heat transfer tube 6C near the base 81. And can melt and evaporate ice.

[Fourth Modification]
FIG. 13: is a principal part schematic perspective view of the heat exchanger which shows the 4th modification of an outdoor unit.
As shown in FIG. 13, in the heat exchanger 4D, an auxiliary heat exchanger 42D may be provided at the inner lower end (leeward side) of the first heat exchanger 41D similar to the conventional heat exchanger.

In this case, the first heat exchanger 41D includes a large number of plate-like fins 51D arranged in the plate thickness direction, and a large number of heat transfer tubes 6D that penetrate the fins 51D and are provided in multiple stages in the longitudinal direction of the fins 51D. And is configured.
The auxiliary heat exchanger 42D includes a plurality of plate-like fins 52D arranged in the plate thickness direction, and a large number of heat transfer tubes 6D that penetrate the fins 52D and are provided in multiple stages in the longitudinal direction of the fins 52D. Configured.

  Thus, the heat exchanger 4D may be frozen in the cold season by providing the auxiliary heat exchanger 42D adjacent to the inner lower end of the first heat exchanger 41D erected on the base 81. The upper surface of the base 81D can be heated by the first heat exchanger 41D and the auxiliary heat exchanger 42D. Further, the heat transfer tubes 6D in the vicinity of the base 81D are respectively disposed in the first heat exchanger 41D and the auxiliary heat exchanger 42D, and thus are arranged in a double manner. For this reason, the double heat transfer tubes 6D heat each other when warm refrigerant flows in the defrost cycle operation, so that the frost and ice on the base 81D can be melted and vaporized. . Therefore, the heat exchanger 4D having a structure in which the heat transfer tube 6D is hardly corroded can be provided.

  Moreover, as shown in FIG. 13, you may install the heat-transfer heater Ht on bottom-plate part 81Da of base 81D of an outdoor unit. The heat transfer heater Ht is composed of, for example, a copper tube heater base extending in the left-right direction at the center of the bottom plate portion 81Da. The heat transfer heater Ht only needs to heat the base 8D, and may be another heater made of a heating wire or the like.

  As described above, the heat exchanger 4D is disposed near the base 81D because the heat transfer heater Ht is installed on the base 81D to melt and vaporize frost and ice adhering to the base 81D. It is possible to prevent the heat transfer tube 6D from corroding for a long time.

[Other variations]
As an example of the embodiment of the present invention, as illustrated in FIG. 2, the front blow type (general household) outdoor unit 1 in which the blower 7 and the outlet 82 a are arranged on the front side of the housing 8 has been described as an example. However, the present invention is not limited to this. The outdoor unit 1 may be an up-blowing type (for building) outdoor unit in which a blower and an air outlet are arranged on the upper side of the housing. That is, the installation direction of the outdoor unit 1 may be changed as appropriate.

  Further, in the embodiment, the first and second modified examples, as an example of the dummy heat transfer tubes 61, 61A, 61B, a hollow pipe composed of the heat transfer tube main body 61a and the lid portion 61b has been described as an example. A rod-shaped member may be used.

  In addition, as an example of the heat exchanger 4, the L-shaped one in plan view has been described as an example, but may be concave in the plan view.

  The heat transfer tube 6 is preferably formed of aluminum or aluminum alloy that has good heat dissipation and is lightweight. The heat transfer tube 6 may be made of copper, copper alloy or the like in addition to aluminum and aluminum alloy.

1 Outdoor unit 4, 4A, 4B, 4C, 4D Heat exchanger 5, 5A, 5B, 5D, 51D, 52D Fin 6, 6A, 6B, 6C, 6D Heat transfer tube 11 Inside / outside connection 61, 61A, 61B, 61C Heat transfer tube 61Ba, 67Ba Groove 62, 62A, 62B, 62C, 63, 63C, 64, 65, 65A, 65C Heat transfer tube 66A, 66B, 67B Heat transfer tube 81, 81D Base 93 Hot gas path 100 Air conditioner Ht Heat transfer heater

Claims (6)

A plurality of plate-like fins arranged in the plate thickness direction, and a plurality of heat transfer tubes provided in a plurality of stages in the longitudinal direction of the fins through the fins, and a refrigerant inside the plurality of heat transfer tubes A heat exchanger that exchanges heat between the air and the refrigerant,
An outdoor unit of an air conditioner, wherein a refrigerant does not flow through at least one heat transfer tube including a heat transfer tube positioned at a lowermost position among the heat transfer tubes. A plurality of plate-like fins arranged in the plate thickness direction, and a plurality of heat transfer tubes provided in a plurality of stages in the longitudinal direction of the fins through the fins, and a refrigerant inside the plurality of heat transfer tubes A heat exchanger that exchanges heat between the air and the refrigerant by blowing air in a direction perpendicular to the plate thickness direction of the fins, and
A base for supporting the heat exchanger,
The outdoor unit of an air conditioner, wherein the plurality of heat transfer tubes are arranged by thinning out one heat transfer tube at each of a lowermost stage and an uppermost stage. A plurality of plate-like fins arranged in the plate thickness direction, and a plurality of heat transfer tubes provided in a plurality of stages in the longitudinal direction of the fins through the fins, and a refrigerant inside the plurality of heat transfer tubes A heat exchanger that exchanges heat between the air and the refrigerant by blowing air in a direction perpendicular to the plate thickness direction of the fins, and
A base for supporting the heat exchanger,
The outdoor unit of an air conditioner, wherein the plurality of heat transfer tubes are provided with grooves in the heat transfer tubes respectively disposed at the lowermost stage and the uppermost stage. The air according to any one of claims 1 to 3, wherein during the defrost cycle operation by the reverse cycle, the refrigerant first flows into the heat transfer tube disposed at the lowest stage. Harmonic outdoor unit. The outdoor unit of an air conditioner according to any one of claims 1 to 4, wherein the heat transfer tube is made of aluminum or an aluminum alloy. On the base, a hot gas path extended from the heat transfer heater or the inside / outside connection part is provided,
The outdoor unit for an air conditioner according to claim 5, wherein the heat transfer heater or the heat radiation portion of the hot gas path is formed of copper or a copper alloy.

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