Heat exchanger

Abstract

A heat exchanger (1) is provided with a plurality of fins (11) and a plurality of heat transfer tubes (12) having a flat cross-sectional shape, the heat transfer tubes (12) being provided in the vertical direction in which the heat transfer tubes (12) are arranged. The fins (11) have openings (112) extending in the vertical direction between the vertically arranged heat transfer tubes (12), and the openings (112) are formed within a range where a first imaginary plane, a second imaginary plane, and a third imaginary plane overlap with each other in a water storage region of the fins (11) sandwiched by the heat transfer tubes (12). (a) the upper and lower end edges of the first imaginary plane are defined by the lower surface (12b) of a first heat transfer tube (12), which is an upper heat transfer tube (12), and a first imaginary line (VL1) extending in the short-side direction of the heat transfer tube (12) at a position between a second heat transfer tube (12), which is a lower heat transfer tube (12) and the first heat transfer tube; (b) the second imaginary plane extends in a direction away from the front edge part (12f) with a second imaginary line (VL2) connecting the front edge part (12f) of the heat transfer pipe (12) as an end edge, and (c) the third imaginary plane extends in a direction close to the front edge part (12f) with a third imaginary line (VL3) connecting the middle part of the heat transfer pipe (12) in the short side direction as an end edge.

Description

Technical Field

[0001] Embodiments of the present invention relate to a heat exchanger. Background Art

[0002] There is a fin-tube heat exchanger, which includes: a plurality of fins arranged at intervals from each other; and a plurality of heat transfer tubes extending in the direction in which the plurality of fins are arranged, penetrating the plurality of fins in the thickness direction thereof, and arranged at intervals from each other in a direction perpendicular to the direction in which the fins are arranged, and having a flat cross-sectional shape.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent No. 6710205 Summary of the Invention

[0006] Problems to be solved by the invention

[0007] During heat exchanger operation, water formed by condensation and adhering to the fins and heat transfer tube surfaces must be properly drained from the heat exchanger. Heat transfer tubes with a flat cross-section (hereinafter sometimes referred to as "flat tubes") offer superior heat transfer performance compared to heat transfer tubes with a circular cross-section (hereinafter sometimes referred to as "round tubes").

[0008] However, due to their cross-sectional shape, flat tubes can actually cause water to drain less smoothly than circular tubes. A related phenomenon is that water outflow from the area between the upper and lower heat transfer tubes (hereinafter sometimes referred to as the "water reservoir") is blocked by the lower heat transfer tube. It has also been confirmed that water flowing over the leading edge of the upper heat transfer tube can penetrate the water reservoir, hindering rapid drainage.

[0009] The above-mentioned document 1 discloses the following technology: between heat transfer tubes arranged vertically, slit-shaped or louver-shaped cut-outs are formed on the fins, and the capillary phenomenon generated in the gaps between the cut-outs and the adjacent fins is utilized to promote the movement of water from the lower surface of the upper heat transfer tube to the upper surface of the lower heat transfer tube within the water storage area.

[0010] This technology drains water generated on and near the lower surface of the upper heat transfer tubes sequentially along the ribs and the lower heat transfer tubes, repeatedly flowing in and out of the water storage area. It is not intended to prevent water from entering the water storage area. In other words, it differs from technologies that achieve rapid drainage by creating a flow of water outside the water storage area.

[0011] In view of such actual conditions, an object of the present invention is to provide a heat exchanger that achieves high heat exchange efficiency and good drainage performance by adopting a heat transfer tube having a flat cross-sectional shape.

[0012] Means for solving problems

[0013] A control device for an air conditioner according to one embodiment of the present invention comprises: a plurality of fins arranged at intervals from each other in a thickness direction; and a plurality of heat transfer tubes having a flat cross-section, extending through each of the plurality of fins in the thickness direction and arranged at intervals from each other in a direction perpendicular to the thickness direction, the heat exchanger being arranged with the direction in which the plurality of heat transfer tubes are arranged as a vertical direction, and airflow passing between the vertically arranged heat transfer tubes in the direction of the short sides of the heat transfer tubes, wherein each of the plurality of fins has an opening extending in the vertical direction between the vertically arranged heat transfer tubes and penetrating the fin in the thickness direction, the opening being formed in a first false position in a region between the vertically arranged heat transfer tubes, i.e., a water storage region of the fin. Within the range where the imaginary plane, the second imaginary plane and the third imaginary plane overlap with each other, (a) the upper and lower end edges of the first imaginary plane are determined by the lower surface of the upper heat transfer tube, i.e., the first heat transfer tube, and a first imaginary line extending along the short side direction of the heat transfer tube at a position intermediate between the upper surface of the lower heat transfer tube, i.e., the second heat transfer tube, and the lower surface of the first heat transfer tube; (b) the second imaginary plane extends in a direction from the leading edge toward the trailing edge on the opposite side thereof, with the second imaginary line connecting the respective leading edges of the first heat transfer tube and the second heat transfer tube as an end edge; and (c) the third imaginary plane extends in a direction approaching the leading edge, with the third imaginary line connecting the respective intermediate portions of the first heat transfer tube and the second heat transfer tube in the short side direction as an end edge.

[0014] The opening may include a through portion formed in the fin by punching in the thickness direction and penetrating the fin.

[0015] Preferably, the opening further includes a protrusion formed by punching and raising the fin in the thickness direction, protruding from a surface of the fin and covering the through portion on one side of the fin in the thickness direction.

[0016] Preferably, the distance between the opening and the second imaginary line is greater than or equal to 1 mm and less than or equal to 4 mm.

[0017] Preferably, the distance between the opening and the lower surface of the first heat transfer tube is 0.5 mm or more and 2 mm or less.

[0018] Preferably, the heat exchanger further includes a ridge portion or a groove portion provided in a portion of the water storage area excluding the range and extending in the up-down direction.

[0019] A control device for an air conditioner according to another embodiment of the present invention comprises: a plurality of fins arranged at intervals from each other in a thickness direction; and a plurality of heat transfer tubes having a flat cross-section, extending through each of the plurality of fins in the thickness direction and arranged at intervals from each other in a direction perpendicular to the thickness direction, wherein the heat exchanger is arranged with the direction in which the plurality of heat transfer tubes are arranged as a vertical direction, and air flows between the vertically arranged heat transfer tubes in the direction of the short sides of the heat transfer tubes, wherein the plurality of fins are respectively arranged between the vertically arranged heat transfer tubes. The area between the heat transfer tubes, i.e., the water storage area, has an opening, which extends in the vertical direction along an imaginary line connecting the leading edges of the respective heat transfer tubes and penetrates the fins in the thickness direction. The heat exchanger is configured so that water flowing from above the upper heat transfer tube, i.e., the first heat transfer tube, of the heat transfer tubes arranged vertically, and passing over the leading edge of the first heat transfer tube, flows downward along the edge of the opening near the leading edge, and then merges with water flowing out of the water storage area and flows below the lower heat transfer tube, i.e., the second heat transfer tube.

[0020] Effects of the Invention

[0021] During operation of a heat exchanger, water generated by condensation and adhering to the surfaces of the fins and heat transfer tubes flows along the fin surfaces, repeatedly condensing as it moves toward the upper surfaces of the heat transfer tubes. This runoff water flows along the upper surfaces of the heat transfer tubes, passing over the leading edges of the heat transfer tubes and spreading downward. Openings are formed within the water storage area of ​​the fins, within the overlapping range of the first, second, and third imaginary surfaces. The runoff water that passes over the leading edges of the heat transfer tubes is restrained from entering the water storage area by surface tension acting around the edges of the openings, and flows downward along the openings. The runoff water then merges with the water flowing out of the water storage area. When the effect of gravity becomes relatively strong, the flow is accelerated by its own weight, allowing it to be rapidly discharged from the heat exchanger.

[0022] In this way, the openings prevent water from flowing over the leading edge of the upper heat transfer tube from entering the water storage area, thereby promoting the flow of water outside the water storage area. Therefore, by using heat transfer tubes with a flat cross-section, a heat exchanger with high heat exchange efficiency and excellent drainage can be provided.

[0023] By forming the openings by punching in the thickness direction of the fins and providing the through-portions penetrating the fins, it is possible to effectively promote the drainage of water and improve the drainage performance.

[0024] The opening portion is formed by punching and cutting the fin in the thickness direction. In addition to the through portion, a protrusion is provided that protrudes from the surface of the fin and covers the through portion. This improves the heat transfer characteristics of the fin and promotes the discharge of water, thereby achieving a balance between heat exchange efficiency and drainage.

[0025] By setting the distance between the opening and the second imaginary plane to 1 mm or more and 4 mm or less, it is possible to form a favorable flow of water along the opening, thereby improving drainage performance.

[0026] By setting the distance between the opening and the lower surface of the first heat exchanger to 0.5 mm or more and 2 mm or less, it is possible to suppress intrusion of water into the opening.

[0027] By providing vertically extending ridges or grooves in the water storage area except for the above-mentioned range, downward flow of water in the water storage area can be actively generated, thereby promoting smooth discharge of water from the water storage area.

[0028] Furthermore, the structure is such that, in the water storage area, an opening portion is formed which extends along an imaginary line connecting the respective leading edges of the heat transfer tubes and passes through the fins in the thickness direction. The flowing water coming from above the upper heat transfer tube, i.e., the first heat transfer tube, among the heat transfer tubes arranged vertically, passes over the leading edge of the first heat transfer tube and flows downward along the edge of the opening portion close to the leading edge portion, and then merges with the water flowing out of the water storage area and flows below the lower heat transfer tube, i.e., the second heat transfer tube. This makes it possible to provide a heat exchanger which achieves high heat exchange efficiency and good drainage by adopting heat transfer tubes with a flat cross-section. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is a schematic diagram showing the configuration of a refrigeration cycle device including a heat exchanger according to one embodiment of the present invention.

[0030] Figure 2 It is a front view showing the structure of the above-mentioned heat exchanger.

[0031] Figure 3 It is a schematic diagram showing the structure of a fin-tube assembly included in the heat exchanger.

[0032] Figure 4 It is a schematic diagram showing the structure of the opening portion provided in the fin of the above-mentioned heat exchanger.

[0033] Figure 5 It is a schematic diagram showing an example of arrangement of the openings in the fin.

[0034] Figure 6 This is a schematic diagram schematically showing the state of water discharge from a heat exchanger.

[0035] Figure 7 This is a schematic diagram showing the structure of a fin-tube assembly included in a heat exchanger according to another embodiment of the present invention. DETAILED DESCRIPTION

[0036] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

[0037] (Configuration of Refrigeration Cycle Device)

[0038] Figure 1 Schematic diagram showing the configuration of a refrigeration cycle device C including a heat exchanger 1 according to an embodiment of the present invention.

[0039] In this embodiment, the heat exchanger 1 is configured as an outdoor heat exchanger and is arranged outdoors.

[0040] Refrigeration cycle device C is configured as an air conditioner and includes, in addition to a heat exchanger 1, a compressor 2, a four-way valve 3, an expansion valve 4, and an indoor heat exchanger 5. It also includes refrigerant piping 6 (6a-6f) connecting these refrigeration cycle elements. Heat exchanger 1 is also equipped with an outdoor fan 1', which draws outdoor air (i.e., outside air) into the interior of the unit. Indoor heat exchanger 5 is also equipped with an indoor fan 5', which draws indoor air into the unit.

[0041] The compressor 2 includes a compressor body 2a and an accumulator 2b. The accumulator 2b separates the refrigerant into gas and liquid and supplies the separated gas refrigerant to the compressor body 2a. The compressor body 2a compresses the supplied gas refrigerant and discharges it as high-temperature and high-pressure gas refrigerant.

[0042] The operation of the refrigeration cycle device C can be switched between cooling operation and heating operation by switching the flow path of the four-way valve 3 .

[0043] (Cooling operation)

[0044] Figure 1 The solid arrow A1 indicates the flow of the refrigerant during the cooling operation.

[0045] During cooling operation, after flowing out of compressor 2, the refrigerant flows through refrigerant piping 6 in the order of four-way valve 3, heat exchanger 1, expansion valve 4, and indoor heat exchanger 5. The high-pressure gas refrigerant compressed by compressor 2 is cooled and condensed by heat exchange with the outside air as it passes through heat exchanger 1. The condensed gas-liquid refrigerant mixture loses pressure as it passes through expansion valve 4, becoming a low-pressure liquid refrigerant that is supplied to indoor heat exchanger 5. The liquid refrigerant flowing into indoor heat exchanger 5 is heated by heat exchange with the indoor air, causing it to evaporate. The evaporated gas-liquid refrigerant then returns to compressor 2 through four-way valve 3.

[0046] (Heating operation)

[0047] Figure 1 The flow of the refrigerant during the heating operation is indicated by a dotted arrow A2.

[0048] During heating operation, after flowing out of compressor 2, the refrigerant flows through refrigerant piping 6 in the order of four-way valve 3, indoor heat exchanger 5, expansion valve 4, and heat exchanger 1. The high-pressure gas refrigerant compressed by compressor 2 is cooled (i.e., releases heat to the indoor air) by heat exchange with the indoor air as it passes through indoor heat exchanger 5, thereby condensing. The condensed gas-liquid refrigerant mixture experiences a pressure drop as it passes through expansion valve 4, becoming a low-pressure liquid refrigerant that is supplied to heat exchanger 1. The liquid refrigerant flowing into heat exchanger 1 is heated (i.e., absorbs heat from the outside air) by heat exchange with the outside air, causing it to evaporate. The evaporated gas-liquid refrigerant then passes through four-way valve 3 and returns to compressor 2.

[0049] (Defrost operation)

[0050] During heating operation, as the refrigerant evaporates in heat exchanger 1, it removes heat from the outside air, causing water vapor in the outside air to condense into water droplets that adhere to heat exchange components (e.g., plate-shaped fins 11) within heat exchanger 1. Due to the low temperature of the outside air, this adhered water may freeze and form frost. In this case, frost hinders heat exchange and may reduce heat exchange efficiency. Therefore, a defrost operation is performed to remove the frost.

[0051] During defrosting operation, the four-way valve 3 is set to the same state as during cooling operation, and the refrigerant is circulated in the same order as during cooling operation. However, both the outdoor fan 1' and the indoor fan 5' are stopped, and the high-temperature, high-pressure gas refrigerant sent from the compressor 2 heats the heat exchange components of the heat exchanger 1, thereby melting the frost, and the dissolved water is discharged from the heat exchanger 1 as drips.

[0052] (Basic structure of outdoor heat exchanger)

[0053] Figure 2 It is a front view showing the structure of the heat exchanger 1.

[0054] The heat exchanger 1 is a so-called fin-and-tube type heat exchanger, and includes a heat exchanger core formed of a fin-and-tube assembly in which heat transfer tubes 12 are assembled to plate-like fins 11 . Figure 2 The heat exchanger core structure after the shell 1a is removed from the heat exchanger 1 is shown. Figure 2 In FIG. 1 , a two-dot chain line schematically indicates the outer shape of the housing 1 a.

[0055] exist Figure 2In the heat exchanger 1 shown, the refrigerant flows in a left-right direction relative to the paper. The direction of the arrow X, which is from right to left relative to the paper, is defined as the X direction. In this embodiment, the X direction coincides with the stacking direction of the plate-shaped fins 11 and the extension direction of the heat transfer tubes 12. On the other hand, outside air passing through the heat exchanger 1 flows from the front side to the back side in a direction perpendicular to the paper. The direction of this outside air flow, i.e., the direction of the arrow Z, is defined as the Z direction. That is, outside air flows through the heat exchanger 1 in the direction indicated by the arrow Z. The front side indicated by the arrow Z is the leeward side, and the opposite root side is the upwind side. Furthermore, the direction of the arrow Y, which is from top to bottom relative to the paper, is defined as the Y direction. The arrow Y is the vertically downward direction, i.e., the direction of gravity, and coincides with the direction in which the heat transfer tubes 12 are arranged.

[0056] The heat exchanger 1 includes a plurality of plate-shaped fins 11, a plurality of heat transfer tubes 12, headers 13 and 14, a gas-side joint 15, and a liquid-side joint 16. In this embodiment, the plate-shaped fins 11 are generally rectangular. The headers 13 and 14 are cylindrical, with their upper and lower ends in the Y direction sealed with a sealant. The gas-side joint 15 is connected to the refrigerant pipe 6 (6b) connected to the four-way valve 3, and the liquid-side joint 16 is connected to the refrigerant pipe 6 (6c) connected to the expansion valve 4.

[0057] The refrigerant flowing from the refrigerant pipe 6 into the heat exchanger 1 flows through the gas-side joint 15 or the liquid-side joint 16 into the headers 13 and 14 on one side, and is distributed to each of the plurality of heat transfer tubes 12. While flowing through the heat transfer tubes 12, the refrigerant exchanges heat with the outside air flowing between the plate-shaped fins 11, condensing or evaporating according to the operating mode of the heat exchanger 1. The condensed or evaporated refrigerant is collected in the other headers 14 and 13, and flows out of the refrigerant pipe 6 through the liquid-side joint 16 or the gas-side joint 15.

[0058] (Detailed Structure of Fin-Tube Assembly)

[0059] Figure 3 It is a schematic diagram showing an enlarged structure of a fin-tube assembly included in the heat exchanger 1 .

[0060] Figure 3 (a) for Figure 2 The fin tube assembly shown is shown as a side view viewed in the X direction, which is the direction in which the plurality of plate-like fins 11 are arranged, that is, the direction in which the plate-like fins 11 are stacked. Figure 3 (b) for Figure 2 The fin tube assembly shown is shown as viewed from the rear as viewed from the downstream side in the flow direction of the external air, that is, in the opposite direction to the Z direction (that is, in the anti-Z direction). Figure 3 (c) indicates Figure 2The fin tube assembly shown. Figure 3 The cross section of line AA shown in (a).

[0061] In this embodiment, the fin-tube assembly includes: a plurality of plate fins 11 arranged at intervals in the thickness direction of the plate fins 11; and a plurality of heat transfer tubes 12 arranged to extend in the stacking direction of the plate fins 11, i.e., in a direction perpendicular to the surfaces of the plate fins 11, and to penetrate the plurality of plate fins 11 in the thickness direction of the plate fins 11. The plurality of heat transfer tubes 12 are arranged at intervals in the thickness direction of the plate fins 11, i.e., in a direction perpendicular to the direction in which the heat transfer tubes 12 extend.

[0062] In actual use, Figure 2 As shown, the heat exchanger 1 is arranged so that the Y direction of the arrayed heat transfer tubes 12 coincides with the vertical direction. In other words, the heat exchanger 1 is arranged so that the plate fins 11 are arranged horizontally and the heat transfer tubes 12 are arranged vertically.

[0063] The heat transfer tube 12 has a flat, generally oval or elliptical cross-section and is formed with a plurality of parallel internal passages 121 through which the refrigerant circulates. These internal passages 121 extend within the heat transfer tube 12 in the X direction, the direction in which the heat transfer tube 12 extends, and are arranged in the Z direction, the direction in which the outside air flows. The X-direction ends of the heat transfer tube 12 are connected to headers 13 and 14, with the internal passages 121 communicating with the header 13 at one end and with the header 14 at the other end.

[0064] The heat transfer tubes 12 are inserted into heat transfer tube insertion portions n formed in each of the plurality of plate-shaped fins 11 and fixed to the plate-shaped fins 11 by brazing or the like, thereby being assembled to the plate-shaped fins 11 . Figure 3 (a) shows a state where a part of the heat transfer tube 12 is removed in order to clearly illustrate the heat transfer tube insertion portion n.

[0065] The heat transfer tube insertion portion n is formed along the cross-sectional shape or outer shape of the heat transfer tube 12, extending in the Z direction. In this embodiment, the heat transfer tube insertion portion n is open at one end edge 11a of the plate-shaped fin 11, which is the direction of flow of external air, i.e., the Z direction, as a notch in the plate-shaped fin 11, and is closed at the other end edge 11b. Specifically, the heat transfer tube insertion portion n terminates between these two ends 11a and 11b, and in this embodiment, is open on the leeward side and closed on the windward side.

[0066] Here, the heat transfer tubes 12 are formed so that their width dimension, defined in the Z direction (i.e., their short sides), is smaller than the width dimension of the plate-shaped fins 11 defined in the same Z direction. The plate-shaped fins 11 are formed so that their length dimension, defined in the Y direction (in which the heat transfer tubes 12 are arranged), is larger than their width dimension. If the thickness dimension of the plate-shaped fins 11 is defined as the dimension defined in the X direction (i.e., the direction in which the heat transfer tubes 12 extend), then the thickness dimension of the plate-shaped fins 11 is smaller than both their width and length dimensions.

[0067] The heat transfer tube insertion portion n can be formed, for example, by punching the plate-shaped fin 11 in the X-direction at the portion where the heat transfer tube insertion portion n is to be formed. As the heat transfer tube insertion portion n is formed, a collar 111 is formed around the periphery of the heat transfer tube insertion portion n, projecting in the punching direction. The collar 111 guides the insertion of the heat transfer tube 12 into the heat transfer tube insertion portion n and supports the inserted heat transfer tube 12.

[0068] (Structure and arrangement of the opening)

[0069] In this embodiment, the plate fins 11 have openings 112 extending through the plate fins 11 in the thickness direction between the vertically arranged heat transfer tubes 12. The openings 112 are rectangular in shape, elongated in the Y direction, in which the heat transfer tubes 12 are arranged, and short in the Z direction, which is the short side of the heat transfer tubes 12.

[0070] The opening 112 is formed in a portion of the water storage area R of the plate-shaped fin 11, which is sandwiched between the vertically arranged heat transfer tubes 12. The water storage area R is defined as follows: the upper and lower boundaries are defined by a horizontal plane including the lower surface 12b of the first heat transfer tube 12 (12u), the upper heat transfer tube of the pair of vertically arranged heat transfer tubes 12, 12, and a horizontal plane including the upper surface 12t of the second heat transfer tube 12 (12l), the lower heat transfer tube. The front and rear boundaries, i.e., the upwind and leeward boundaries, are defined by a vertical plane connecting the upwind leading edge portions 12f of the pair of heat transfer tubes 12 (12u, 12l) and a vertical plane connecting the leeward trailing edge portions 12r.

[0071] Here, three imaginary straight lines (hereinafter referred to as "imaginary lines") are defined for the plate-shaped fin 11: a first imaginary line VL1, a second imaginary line VL2, and a third imaginary line VL3. In this embodiment, the first imaginary line VL1 is a straight line defined horizontally (in the Z direction) at the midpoint between the upper surface 12t of the second heat transfer tube 12l and the lower surface 12b of the first heat transfer tube 12u in the Y direction. The second imaginary line VL2 is a straight line defined vertically (in the Y direction) connecting the leading edges 12f of the first and second heat transfer tubes 12u, 12l. Furthermore, the third imaginary line VL3 is a straight line defined vertically (in the Y direction) connecting the midpoints of the first and second heat transfer tubes 12u, 12l in the Z direction. The opening 112 is formed in the water storage area R in a range where the first imaginary plane, the second imaginary plane, and the third imaginary plane overlap with each other, wherein the upper and lower end edges of the first imaginary plane are determined by the lower surface 12b of the first heat transfer tube 12u and the first imaginary line VL1, the second imaginary plane extends in a direction away from the leading edge 12f, i.e., from the leading edge 12f toward the trailing edge 12r, with the second imaginary line VL2 as the end edge on the upwind side, and the third imaginary plane extends in a direction approaching the leading edge 12f, with the third imaginary line VL3 as the end edge on the leeward side. In other words, when the width dimension of the heat transfer tube 12 is set to Dwf and the distance between the lower surface 12b of the first heat transfer tube 12u and the upper surface 12t of the second heat transfer tube 12l is set to Ddf, the opening portion 112 is located in a range from the front edge 12f of the first heat transfer tube 12u along the flow direction of the external air to a distance Dwf / 2, and in a range from the lower surface 12b of the first heat transfer tube 12u vertically downward to a distance Ddf / 2.

[0072] Moreover, the distance between the opening portion 112 and the second imaginary line VL2, specifically the distance Dga between the upwind edge of the opening portion 112 and the second imaginary line VL2 is preferably greater than 1 mm and less than 4 mm, and the distance between the opening portion 112 and the first heat transfer tube 12u, specifically the distance Dgb between the upper edge of the opening portion 112 and the lower surface 12b of the first heat transfer tube 12u is preferably greater than 0.5 mm and less than 2 mm.

[0073] Figure 4 This is a schematic diagram showing a specific example of the opening 112 of the plate-like fin 11 applicable to the heat exchanger 1 of the present embodiment.

[0074] Figure 4 (a) shows an example in which the plate-shaped fin 11 is punched out in the thickness direction to form a through portion 112a, and the opening 112 is formed by using the through portion 112a. Figure 4 (a) and Figure 4 In (b) and (c), for the convenience of illustration, the through portion 112a is indicated by an oblique line. Figure 4 The example shown in (a) does not have a structure equivalent to the protrusion 112b of the opening portion 112 described next, and the projection of the peripheral portion of the opening portion 112 relative to a plane perpendicular to the flow direction (Z direction) of the external air has the same size as the thickness of the plate-shaped fin 11 in the thickness direction (X direction) of the plate-shaped fin 11.

[0075] like Figure 4 (b) and Figure 4 As shown in (c), the opening 112 can also be formed by punching and cutting the plate-like fin 11 in the thickness direction (X direction). In this case, the opening 112 includes a through portion 112a that penetrates the plate-like fin 11 in the thickness direction, and a protruding portion 112b that protrudes from the surface of the plate-like fin 11 and covers the through portion 112a on one side of the plate-like fin 11 in the thickness direction.

[0076] Figure 4 (b) and Figure 4 (c) shows a specific example of the opening 112 having the protruding portion 112b. Figure 4 (b) shows the opening 112 formed into a slit shape. Figure 4 (c) shows a louver-shaped opening 112. The slit-shaped opening 112 opens the through-portion 112a toward both the leading edge 12f and the trailing edge 12r of the heat transfer tube 12, that is, in this embodiment, toward both the upwind and leeward sides of the outside air flow direction. In contrast, the louver-shaped opening 112 opens the through-portion 112a toward the leading edge 12f of the heat transfer tube 12, that is, toward the upwind side. Meanwhile, the through-portion 112a is closed by the protrusion 112b toward the trailing edge 12l of the heat transfer tube 12, that is, toward the leeward side.

[0077] Figure 5 It is a schematic diagram showing an example of arrangement of the openings 112 in the plate-shaped fin 11 .

[0078] Figure 5 (a) shows an example in which one opening 112 is arranged perpendicularly to the flow direction of the outside air, in other words, the longitudinal direction of the opening 112 is arranged to coincide with the vertical direction or the direction of gravity.

[0079] Figure 5 (b) shows an example in which the opening 112 is arranged to be inclined with respect to the flow direction of the outside air. The number of the openings 112 is not limited to one, and may be a plurality.

[0080] Figure 5(c) shows an example in which a plurality of openings 112 are arranged. The plurality of openings 112 are arranged in a row in the direction of flow of the outside air. The plurality of openings 112 may be arranged parallel to each other or may be arranged obliquely.

[0081] (Explanation of the effects)

[0082] The heat exchanger 1 of this embodiment has the above-described configuration. Hereinafter, the effects obtained by this embodiment will be described.

[0083] Figure 6 This is a schematic diagram schematically showing the heat exchanger 1 , particularly the state of drainage from the water storage area R. Figure 6 (a) shows a case where the opening portion 112 of the present embodiment is provided with the opening portion 112 formed in a louver shape. Figure 6 (b) shows a case where the opening 112 is not provided, that is, a case where the surface of the water storage area R is formed of a continuous single plane.

[0084] During operation of the heat exchanger 1, water generated by condensation and adhering to the surfaces of the plate-shaped fins 11 and heat transfer tubes 12 needs to be properly drained from the heat exchanger 1. While the heat transfer tubes 12, with their flat cross-section, offer excellent heat transfer performance and contribute to high heat exchange efficiency, their cross-sectional shape sometimes prevents smooth drainage.

[0085] Here, if we focus on the two heat transfer tubes 12 arranged vertically (the first heat transfer tube 12u on the upper side and the second heat transfer tube 12l on the lower side) and the water storage area R between them, the water generated in the water storage area R and attached to the surface of the plate fins 11 and the heat transfer tubes 12 flows downward under the action of gravity, repeatedly condensing and moving toward the upper surface of the heat transfer tubes 12 and its vicinity (arrow a1). Figure 6 (a) and Figure 6 (b) schematically shows water collected near the upper surface of the heat transfer tube 12 by two-dot chain frames W1 and W2.

[0086] Moreover, the water W1 and W2 flow along the upper surface of the heat transfer tube 12 toward the leading edge 12f and the trailing edge 12r, that is, toward the upwind side and the leeward side. If the water flowing to the leeward side reaches the trailing edge 12r of the heat transfer tube 12, it will separate from the heat transfer tube 12 and scatter with the flow of external air.

[0087] exist Figure 6In the comparative example shown in (b), water flowing to the windward side (arrow a2) passes over the leading edge 12f of the first heat transfer tube 12u, flows along the lower surface of the first heat transfer tube 12u, and meanders downward, entering the water storage area R directly below (arrows a31 and a32). This entering water then merges with the water W2 in the water storage area R to form a larger water mass, which then flows out of the water storage area R (arrow a4). Thus, in the comparative example, the water that passes over the leading edge 12f of the first heat transfer tube 12u and enters the water storage area R presents a problem of hindering smooth drainage from the water storage area R.

[0088] In contrast, in this embodiment, Figure 6 As shown in (a), an opening 112 is formed along the leading edge of the water storage area R, in other words, along the second imaginary line VL2 connecting the leading edges 12f of the upper and lower heat transfer tubes 12. Consequently, surface tension effectively acts on the peripheral edge of the opening 112, particularly the upwind edge near the leading edge 12f (hereinafter sometimes referred to as the "long side of the opening"), against water entering the water reservoir area R. This surface tension hinders the movement of water across the opening 112 in the direction of the outside air flow, causing the water to flow downward along the opening 112 and toward the lower heat transfer tube 12, namely, the second heat transfer tube 12l (arrow a5). Water flowing out of the water storage area R (arrow a4) then merges below the opening 112 or around the lower end of the opening 112, forming a larger mass of water. This mass is then significantly affected by gravity and flows downward outside the water storage area R.

[0089] Thus, according to this embodiment, the opening 112 prevents water from flowing over the leading edge 12f of the upper heat transfer tube 12 (first heat transfer tube 12u) and entering the water storage area R, thereby promoting the flow of water outside the water storage area R, that is, outside the second imaginary line VL2 relative to the water storage area R. Therefore, by adopting the heat transfer tube 12 having a flat cross-sectional shape, a heat exchanger 1 can be provided that achieves high heat exchange efficiency and excellent drainage performance.

[0090] Moreover, such an effect is not limited to the defrosting operation of the refrigeration cycle device C, but can also be obtained during the normal heating operation when the outdoor fan 1' is working. By forming the opening portion 112, the water attached to the surface of the plate fin 11 or the heat transfer tube 12 during the heating operation can be promoted to be discharged from the heat exchanger 1.

[0091] Here, by forming the opening 112 within the range where the first, second, and third imaginary planes overlap in the water storage area R, drainage performance can be effectively improved. The upper and lower edges of the first imaginary plane are defined by the lower surface of the upper heat transfer tube 12 (the first heat transfer tube 12u) and a first imaginary line VL1 defined in the horizontal direction (Z direction) at a position intermediate between the pair of heat transfer tubes 12 arranged vertically. The second imaginary plane has a second imaginary line VL2 defined in the vertical direction (Y direction) connecting the leading edges 12f of the pair of heat transfer tubes 12 as its edge, and extends in a direction from the leading edge 12f toward the trailing edge 12r on the opposite side thereof. The third imaginary plane has a third imaginary line VL3 defined in the vertical direction connecting the intermediate portions of the pair of heat transfer tubes 12 in the short-side direction (Z direction) as its edge, and extends in a direction approaching the leading edge 12f.

[0092] By setting the range of the opening 112 to a position above the first imaginary line VL1, it is possible to prevent the water in the water storage area R from being obstructed from flowing out of the water storage area R, avoid excessive accumulation of water on the upper surface 12t of the heat transfer tube 12 or in the vicinity thereof, and achieve higher drainage performance.

[0093] Furthermore, by limiting the range in which the openings 112 are formed, heat transfer in the plate-like fins 11 is hindered by the openings 112 , and adverse effects of the openings 112 on the heat transfer characteristics of the plate-like fins 11 can be suppressed.

[0094] exist Figure 6 In the description, the following is used: Figure 4 The opening 112 is formed as a louver as shown in (c), but is not limited thereto. The opening 112 may also be formed as Figure 4 Form the through portion 112a as shown in (a) of FIG. 1 , or Figure 4 As shown in (b), a slit-shaped or other shaped protrusion 112b is attached to the through-hole 112a to cover it. In this way, the heat transfer characteristics of the plate-shaped fin 11 can be improved while achieving a balance between drainage performance. Figure 4 The example shown in (a) can suppress ventilation resistance and promote the smooth flow of external air.

[0095] The opening 112 can not only Figure 5 As shown in (a), the longitudinal direction is formed in accordance with the vertical direction or the gravity direction, or as shown in (a) Figure 5 As shown in (b), the water flowing along the opening 112 is inclined, thereby making it possible to have a flow velocity component in the direction away from the water storage area R, and more actively promote drainage from the water storage area R. Figure 5As shown in (c), by arranging a plurality of openings 112 in the short side direction of the heat transfer tube 12, which is the flow direction of the external air, i.e., the Z direction in this embodiment, when there is water that has passed through the opening 112 on one side and has penetrated into the water storage area R, the further penetration of the water can be suppressed through the opening 112 on the other side, thereby promoting the discharge of water from the water storage area R.

[0096] The opening 112 is preferably formed at an appropriate distance Dga from the second imaginary line VL2. This allows for optimal surface tension acting on water at the periphery of the opening 112, particularly along the long side near the leading edge 12f. The distance Dga is preferably 1 mm to 4 mm.

[0097] Furthermore, the opening 112 is preferably formed at an appropriate distance Dgb from the lower surface 12b of the upper heat transfer tube 12. This prevents water generated near the lower surface 12b of the upper heat transfer tube 12 from entering the opening 112 and promotes the movement of water flowing along the peripheral edge of the opening 112, particularly along the long side near the leading edge 12f. The distance Db is preferably not less than 0.5 mm and not more than 2 mm.

[0098] (Other embodiments)

[0099] In the water storage region R, not only the opening 112 but also convex or concave portions extending in the up-down direction may be formed. Figure 7 This is a schematic diagram showing an example in which, as another embodiment of the present invention, a plate-shaped fin 11 is provided with a concave-convex portion 113 in addition to the opening 112 .

[0100] like Figure 7 As shown, the concave-convex portion 113 is formed of a plurality of ridges 113a and 113b that are arranged continuously in the direction of outside air flow, i.e., the short side direction of the heat transfer tube 12, and extend perpendicular to the outside air flow direction. The ridges formed by the concave-convex portion 113 include: a first ridge 113a, formed below the opening 112, i.e., between the upper surface 12t of the heat transfer tube 12 on the lower side and the first imaginary line VL1, and shorter in the vertical direction; and a second ridge 113b, formed on the opposite side of the opening 112 from the second imaginary line VL2, in this embodiment, between the second imaginary line VL2 and the third imaginary line VL3 and on the leeward side of the opening 112, and longer in the vertical direction than the first ridge 113a. Furthermore, in addition to the convex portions 113a and 113b, the concave-convex portion 113 further forms concave portions extending in the vertical direction between adjacent first convex portions 113a and 113a and between the first convex portion 113a and the second convex portion 113b.

[0101] In this manner, the concave-convex portion 113 is formed in addition to the opening 112 in the water storage area R. This prevents water from flowing over the leading edge 12f of the upper heat transfer tube 12 from entering the water storage area R, and promotes the movement of water in the water storage area R due to its own weight, that is, the flow toward the upper surface 12t of the lower heat transfer tube 12, thereby promoting drainage from the water storage area R. Consequently, drainage performance can be further improved.

[0102] In the above description, the headers 13 and 14 are shown as cylindrical headers, but the headers 13 and 14 are not limited thereto and may be, for example, stacked headers formed by stacking plate-like plates.

[0103] In addition, the plate-shaped fin 11 is not limited to a planar shape in the portion other than the opening 112 and the concave-convex portion 113. For example, it can also be a shape having a step portion extending in the direction of arrangement of the heat transfer tubes 12, that is, in the Y direction, in the portion outside the water storage area R, which in this embodiment is the area on the upwind side of the second imaginary line VL2.

[0104] Furthermore, the direction of outside air flowing between the plate-shaped fins 11 is not limited to the Z direction; it may also be the opposite Z direction. In this case, the outside air passes through the water storage area R from the trailing edge 12r toward the leading edge 12f of the heat transfer tube 12. Furthermore, regarding the demarcation of the range forming the opening 112, the leeward edge of the second imaginary plane is defined by the second imaginary line VL2, and the upwind edge of the third imaginary plane is defined by the third imaginary line VL3.

[0105] Furthermore, in the louver-shaped opening 112, the direction in which the through-portion 112a opens is not limited to the direction toward the leading edge 12f of the heat transfer tube 12, but may also be toward the trailing edge 12r. In other words, the louver-shaped opening 112 may be shaped so that the through-portion 112a opens toward the trailing edge 12r of the heat transfer tube 12 and closes toward the leading edge 12f.

[0106] While several embodiments of the present invention have been described, these embodiments are provided as examples and are not intended to limit the scope of the invention. These new embodiments may be implemented in various other ways, and various omissions, substitutions, and modifications may be made without departing from the spirit of the invention. These embodiments and their variations are intended to be within the scope and spirit of the invention and are encompassed by the invention as set forth in the claims and their equivalents.

[0107] Description of Reference Numerals

[0108] C…refrigeration cycle device; 1…heat exchanger (outdoor heat exchanger); 1a…housing; 1′…outdoor fan; 2…compressor; 2a…compressor body; 2b…liquid accumulator; 3…four-way valve; 4…expansion valve; 5…indoor heat exchanger; 5′…indoor fan; 6, 6a to 6f…refrigerant piping; 11…plate fin; 111…collar; 12…heat transfer tube; 121…internal passage; 13, 14…manifold; 15…gas-side connector; 16…liquid-side connector; X…thickness direction of the plate fin, extension direction of the heat transfer tube; Y…arrangement direction of the heat transfer tube; Z…flow direction of the outside air; R…water storage area; VL1…first imaginary line; VL2…second imaginary line; VL3…third imaginary line.

Claims

1. A heat exchanger comprising: a plurality of fins arranged at intervals from each other in the thickness direction; and A plurality of heat transfer tubes having a flat cross-sectional shape extend through the plurality of fins in the thickness direction and are arranged at intervals from each other in a direction perpendicular to the thickness direction. The heat exchanger is arranged in the vertical direction with the direction of arrangement of the plurality of heat transfer tubes, and the air flow passes between the vertically arranged heat transfer tubes along the short side direction of the heat transfer tubes, wherein: Each of the plurality of fins has an opening extending in the vertical direction between the vertically arranged heat transfer tubes and penetrating the fin in the thickness direction. The opening is formed in the area between the vertically arranged heat transfer tubes, i.e., in the water storage area of ​​the fin, within the range where the first imaginary plane, the second imaginary plane, and the third imaginary plane overlap with each other. The upper and lower edges of the first imaginary surface are defined by a first imaginary line extending in the short-side direction of the heat transfer tubes, midway between the upper surface of the first heat transfer tube and the lower surface of the first heat transfer tube. The second imaginary surface has a second imaginary line connecting the leading edges of the first and second heat transfer tubes as an end edge, and extends from the leading edge toward the trailing edge on the opposite side thereof. The third imaginary surface extends in a direction approaching the front edge portion, with a third imaginary line connecting the intermediate portions of the first heat transfer tube and the second heat transfer tube in the short-side direction as an end edge.

2. The heat exchanger according to claim 1, wherein The opening has a through portion that is formed in the fin by punching in the thickness direction and penetrates the fin.

3. The heat exchanger according to claim 2, wherein The opening further includes a protrusion formed by punching and raising the fin in the thickness direction, protruding from a surface of the fin and covering the through portion on one side of the fin in the thickness direction.

4. The heat exchanger according to claim 1, wherein The distance between the opening and the second imaginary line is greater than or equal to 1 mm and less than or equal to 4 mm.

5. The heat exchanger according to claim 1, wherein A distance between the opening and the lower surface of the first heat transfer tube is not less than 0.5 mm and not more than 2 mm.

6. The heat exchanger according to any one of claims 1 to 5, wherein: The heat exchanger further includes a ridge or groove provided in a portion of the water storage area excluding the range and extending in the up-down direction.

7. A heat exchanger comprising: a plurality of fins arranged at intervals from each other in the thickness direction; and A plurality of heat transfer tubes having a flat cross-sectional shape extend through the plurality of fins in the thickness direction and are arranged at intervals from each other in a direction perpendicular to the thickness direction. The heat exchanger is arranged in the vertical direction with the direction of arrangement of the plurality of heat transfer tubes, and the air flow passes between the vertically arranged heat transfer tubes along the short side direction of the heat transfer tubes, wherein: Each of the plurality of fins has an opening in a water storage area between the vertically arranged heat transfer tubes. The opening extends in the vertical direction along an imaginary line connecting the leading edges of the heat transfer tubes and penetrates the fin in the thickness direction. The heat exchanger is constructed as follows: The water flowing down from the upper heat transfer tube, i.e., the first heat transfer tube, among the heat transfer tubes arranged vertically, flows over the front edge of the first heat transfer tube and flows downward along the edge of the opening near the front edge, and then merges with the water flowing out of the water storage area and flows below the lower heat transfer tube, i.e., the second heat transfer tube.

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