Heat exchanger and refrigeration cycle device

Abstract

The purpose of the present invention is to obtain a heat exchanger and a refrigeration cycle device with which it is possible to improve the drainage of corrugated fins. A heat exchanger is provided with: a plurality of flat heat transfer tubes each having a flat cross-section, having planar outer surfaces disposed facing each other, and forming a flow path for a fluid therein; and corrugated fins which have a corrugated shape and are arranged between the flat heat transfer tubes facing each other, the crests of the corrugated shape being joined to the flat heat transfer tubes, the crests forming fins between the crests, the fins being arranged in the height direction, each fin having a drainage slit for discharging water on the fin, and the drainage slits being arranged between the crests of the corrugated shape and the flat heat transfer tubes facing each other. The horizontal end portions of the drainage slits of the fins adjacent to each other in the height direction are located at different positions from each other.

Description

[0001] This invention application is a divisional application of an invention patent application with an application date of November 11, 2019, application number 201980102001.8 (international application number PCT / JP2019 / 044086), and invention name “Heat exchanger and refrigeration cycle device”. Technical Field

[0002] The present invention relates to a heat exchanger and a refrigeration cycle device, and more particularly to a heat exchanger and an air conditioner composed of a combination of corrugated fins and flat heat transfer tubes. Background Art

[0003] For example, a corrugated fin tube type heat exchanger in which corrugated fins are arranged between the flat portions of a plurality of flat heat transfer tubes connected between a pair of headers through which the refrigerant passes has become popular. Furthermore, between the flat heat transfer tubes provided with the corrugated fins, gas passes as an airflow. In such a heat exchanger, the surface temperature of at least one of the flat heat transfer tubes and the corrugated fins may be below the freezing point. If the surface temperature decreases, water in the air near the surface is separated out to become water, and if it becomes below the freezing point, the water freezes. Therefore, in order to drain water, there is a heat exchanger in which a slit is provided as a gap in the portion that becomes the fin, and the water separated on the surface is discharged through the slit (for example, refer to Patent Document 1).

[0004] Prior Art Literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Publication No. 2015-183908 Summary of the invention

[0007] Problems to be solved by the invention

[0008] As described above, conventional heat exchangers have a structure for discharging water precipitated on the surface of the corrugated fins. However, if water is retained in the corrugated fins, it is difficult to discharge the retained water. The retained water freezes and becomes a resistance to the air passing through the heat exchanger, which is the main reason for reducing the heat transfer performance of the corrugated fins.

[0009] An object of the present invention is to solve the above-mentioned problems and to provide a heat exchanger and a refrigeration cycle device capable of improving the drainage performance of the corrugated fins.

[0010] Solutions to Solve Problems

[0011] The heat exchanger of the present invention comprises: a plurality of flat heat transfer tubes having a flat cross-section and planar outer surfaces arranged facing each other, the tubes forming a flow path for the fluid; and corrugated fins having a wave shape and arranged between the facing flat heat transfer tubes, the tops of the wave shape being joined to the flat heat transfer tubes, the spaces between the tops forming fins, the fins being arranged in a height direction, wherein each fin has a drainage slit for draining water on the fin, and the ends of the drainage slits of the fins adjacent to each other in the height direction are located at different positions in the horizontal direction.

[0012] Furthermore, a refrigeration cycle device of the present invention includes the above-mentioned heat exchanger.

[0013] Effects of the Invention

[0014] The heat exchanger of the present invention is provided with corrugated fins, and among the drainage slits of the fins, at least the ends of the drainage slits in the horizontal direction of the fins adjacent in the height direction are located at different positions in the height direction. Therefore, water from the upper fins can be combined with water from the lower fins for drainage. Therefore, it is possible to suppress the retention of water in the fins, prevent freezing, etc., and further improve the heat transfer performance of the corrugated fins. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a diagram for explaining the structure of the heat exchanger according to Embodiment 1.

[0016] Figure 2 This is a diagram for explaining the corrugated fin according to the first embodiment.

[0017] Figure 3 This is a diagram showing the configuration of an air-conditioning apparatus according to Embodiment 1.

[0018] Figure 4 This is a diagram for explaining the positional relationship between the drainage slits in each fin of the corrugated fin according to the first embodiment.

[0019] Figure 5 This is a diagram for explaining the flow of condensed water on the surface of the fin 21 according to the first embodiment.

[0020] Figure 6 This is a diagram for explaining an example of drainage slits included in the corrugated fins of the heat exchanger according to the second embodiment.

[0021] Figure 7 This is a diagram for explaining another example (Part 1) of the drainage slits included in the corrugated fins of the heat exchanger according to the second embodiment.

[0022] Figure 8 This is a diagram for explaining another example (Part 2) of the drainage slits included in the corrugated fins of the heat exchanger according to the second embodiment.

[0023] Fig. 9 This is a diagram for explaining another example (Part 3) of the drainage slits included in the corrugated fins of the heat exchanger according to the second embodiment.

[0024] Fig.10 This is a diagram for explaining another example (Part 4) of the drainage slits included in the corrugated fins of the heat exchanger according to the second embodiment.

[0025] Fig.11 This is a diagram for explaining the corrugated fins of the heat exchanger according to the third embodiment.

[0026] Fig.12 It is a figure which shows the state of the corrugated fin before corrugation process in Embodiment 3.

[0027] Fig.13 This is a diagram for explaining another example (Part 1) of the corrugated fin of the heat exchanger according to the third embodiment.

[0028] Fig.14 This is a diagram showing a state of a corrugated fin before corrugation according to another example of the third embodiment.

[0029] Fig.15 This is a diagram for explaining another example (Part 2) of the position of the drain slit of the heat exchanger according to the third embodiment.

[0030] Fig.16 This is a diagram for explaining the position of the drain slit of the heat exchanger according to the fourth embodiment.

[0031] Fig.17 This is a diagram for explaining the position of the drain slit of the heat exchanger according to the fifth embodiment.

[0032] Fig.18 This is a diagram for explaining an example of a method for manufacturing the corrugated fin according to the sixth embodiment. DETAILED DESCRIPTION

[0033] Hereinafter, the heat exchanger and the air conditioner of the embodiment will be described with reference to the accompanying drawings and the like. In the following drawings, the parts marked with the same reference numerals are the same or equivalent parts, and are common in the full text of the embodiment described below. Moreover, the forms of the components represented in the full text of the specification are only illustrative and are not limited to the forms described in the specification. In particular, the combination of components is not limited to the combination in each embodiment, and the components described in other embodiments can also be applied to other embodiments. In addition, in the following description, the upper side in the figure is described as the "upper side" and the lower side is described as the "lower side". Moreover, for easy understanding, terms indicating directions (such as "right", "left", "front", "back", etc.) are appropriately used, but this is only for explanation and is not limited to these terms. In addition, the height of humidity and temperature is not particularly determined based on the relationship with the absolute value, but is relatively determined in the state and action of the device, etc. Moreover, in the accompanying drawings, the size relationship of each component is sometimes different from the actual one. Implementation Method 1

[0034] Figure 1 1 is a diagram illustrating the structure of the heat exchanger of Embodiment 1. Figure 1 As shown, the heat exchanger 10 of the first embodiment is a corrugated fin tube type heat exchanger in a parallel pipe configuration. The heat exchanger 10 includes a plurality of flat heat transfer tubes 1, a plurality of corrugated fins 2, and a pair of headers 3 (header 3A and header 3B). Figure 1 The up and down direction in is taken as the height direction. Figure 1 The left and right directions in are taken as the horizontal directions. Figure 1 The front-to-back direction in is taken as the depth direction.

[0035] The header 3 is a pipe that is connected to other devices constituting the refrigeration cycle device, allows the refrigerant, a fluid that is a heat exchange medium, to flow in and out, and allows the refrigerant to branch or merge. Between the two headers 3, a plurality of flat heat transfer tubes 1 are arranged in parallel in a manner perpendicular to each header 3. Figure 1 As shown, in the heat exchanger 10 of Embodiment 1, two headers 3A and 3B are arranged separately in the height direction. The header 3A through which the liquid refrigerant passes is located at the lower side, and the header 3B through which the gaseous refrigerant passes is located at the upper side.

[0036] In addition, the flat heat transfer tube 1 is a heat transfer tube having a flat cross-section, the outer side surface of the long side of the flat shape along the air flow direction, i.e., the depth direction is flat, and the outer side surface of the short side orthogonal to the long side direction is curved. The flat heat transfer tube 1 is a porous flat heat transfer tube having a plurality of holes inside the tube that serve as flow paths for the refrigerant. In Embodiment 1, since the holes of the flat heat transfer tube 1 serve as flow paths between the headers 3, they are formed in the height direction. Moreover, the outer side surfaces of the long sides of each flat heat transfer tube 1 face each other and are arranged at equal intervals in the horizontal direction. When manufacturing the heat exchanger 10 of Embodiment 1, each flat heat transfer tube 1 is inserted into an insertion hole (not shown) provided in each header 3 and brazed together. For example, a brazing material containing aluminum is used for brazing.

[0037] Here, when the heat exchanger 10 is used as a condenser, a high-temperature and high-pressure refrigerant flows in the refrigerant flow path in the flat heat transfer tube 1. In addition, when the heat exchanger 10 is used as an evaporator, a low-temperature and low-pressure refrigerant flows in the refrigerant flow path in the flat heat transfer tube 1. The refrigerant flows into one header 3 via a pipe (not shown) that supplies the refrigerant to the heat exchanger 10 from an external device (not shown). The refrigerant that has flowed into one header 3 is distributed and passes through each flat heat transfer tube 1. The flat heat transfer tube 1 performs heat exchange between the refrigerant passing through the tube and the outside air that is the outside atmosphere passing outside the tube. At this time, the refrigerant dissipates heat to the atmosphere or absorbs heat from the atmosphere while passing through the flat heat transfer tube 1. When the temperature of the refrigerant is higher than the temperature of the outside air, the refrigerant releases its own heat to the outside air. When the temperature of the refrigerant is lower than the temperature of the outside air, the refrigerant absorbs heat from the atmosphere. The refrigerant that has undergone heat exchange through the flat heat transfer tube 1 flows into the other header 3 and merges. Then, the refrigerant flows back to an external device (not shown) through a pipe (not shown) connected to the other header 3 .

[0038] In addition, corrugated fins 2 are arranged between the mutually facing flat surfaces of the arranged flat heat transfer tubes 1. The corrugated fins 2 are arranged to expand the heat transfer area between the refrigerant and the outside air. The corrugated fins 2 are formed by corrugating the plate material and repeatedly bending it in a serpentine manner by convex and concave folding, thereby bending it into a corrugated shape to form a zigzag shape. Here, the convex and concave bending portion formed into a wave shape becomes the top of the wave shape. In the first embodiment, the tops of the corrugated fins 2 are arranged in the entire height direction.

[0039] Figure 2This is a diagram for explaining the corrugated fin of Embodiment 1. In the corrugated fin 2, except for one end portion protruding from between the opposing flat heat transfer tubes 1 to the upstream side in the air flow direction, the top of the wave shape in the corrugated fin 2 is in surface contact with the flat surface of the flat heat transfer tube 1. And the contact portion is brazed together by brazing filler metal. The plate material of the corrugated fin 2 is, for example, made of aluminum alloy. And a brazing filler metal layer is coated on the surface of the plate material. The coated brazing filler metal layer is, for example, based on an aluminum-containing brazing filler metal of the aluminum silicon system. Here, the plate thickness of the plate material is about 50 μm to 200 μm.

[0040] The surface at the belly between the tops of the corrugated fins 2 is the fin 21. Each fin 21 has a louver 22 and a drainage slit 23. A plurality of louvers 22 are arranged in the air flow direction, i.e., the depth direction, in each fin 21. Therefore, the louvers 22 are arranged along the air flow. The louvers 22 have slits for allowing air to pass through and a plate portion for guiding the air passing through the slits. In addition, the drainage slit 23 is arranged in a position corresponding to the central portion of the flat heat transfer tube 1 in the depth direction in each fin 21. The drainage slit 23 is formed into a rectangular shape extending long in the horizontal direction. Here, as described later, the drainage slit 23 of the heat exchanger 10 of Embodiment 1 has a central position of the slit in the horizontal direction that is staggered between adjacent fins 21 at least in the height direction, and the position of the end of the drainage slit 23 in the horizontal direction is also different. The corrugated fin 2 will be further described later.

[0041] Figure 3 1 is a diagram showing a configuration of an air conditioning apparatus according to Embodiment 1. In Embodiment 1, the air conditioning apparatus is described as an example of a refrigeration cycle apparatus. Figure 3 In the air conditioning device of FIG. 1 , the heat exchanger 10 is used as the outdoor heat exchanger 230 . However, the present invention is not limited thereto, and the heat exchanger 10 may be used as the indoor heat exchanger 110 or may be used for both the outdoor heat exchanger 230 and the indoor heat exchanger 110 .

[0042] like Figure 3 As shown, the air conditioning apparatus is formed by connecting an outdoor unit 200 and an indoor unit 100 by piping using a gas refrigerant piping 300 and a liquid refrigerant piping 400. The outdoor unit 200 includes a compressor 210, a four-way valve 220, an outdoor heat exchanger 230, and an outdoor fan 240. The air conditioning apparatus of Embodiment 1 is formed by connecting one outdoor unit 200 and one indoor unit 100 by piping.

[0043] The compressor 210 compresses the sucked refrigerant and discharges it. Although not particularly limited, the compressor 210 can change the capacity of the compressor 210 by arbitrarily changing the operating frequency, for example, using an inverter circuit. The four-way valve 220 is a valve that switches the flow of the refrigerant, for example, between cooling operation and heating operation.

[0044] The outdoor heat exchanger 230 performs heat exchange between the refrigerant and the outdoor air. For example, during heating operation, it functions as an evaporator to evaporate and gasify the refrigerant. In addition, during cooling operation, it functions as a condenser to condense and liquefy the refrigerant. The outdoor fan 240 sends outdoor air into the outdoor heat exchanger 230 to promote heat exchange in the outdoor heat exchanger 230.

[0045] The indoor heat exchanger 110 performs heat exchange between indoor air and refrigerant, for example, and functions as a condenser to condense and liquefy the refrigerant during heating operation, and functions as an evaporator to evaporate and gasify the refrigerant during cooling operation.

[0046] On the other hand, the indoor unit 100 has an indoor heat exchanger 110, an expansion valve 120, and an indoor fan 130. The expansion valve 120, such as a throttling device, decompresses the refrigerant and expands it. For example, when it is composed of an electronic expansion valve, the opening is adjusted based on the instructions of a control device (not shown). In addition, the indoor heat exchanger 110 performs heat exchange between the indoor air and the refrigerant in the air-conditioned space. For example, during the heating operation, it functions as a condenser to condense and liquefy the refrigerant. In addition, during the cooling operation, it functions as an evaporator to evaporate and gasify the refrigerant. The indoor fan 130 passes the indoor air through the indoor heat exchanger 110, and supplies the air that has passed through the indoor heat exchanger 110 to the room.

[0047] Next, the operation of each device of the air conditioning apparatus will be described based on the flow of the refrigerant. First, the operation of each device of the refrigerant circuit in the heating operation will be described based on the flow of the refrigerant. The high-temperature and high-pressure gas refrigerant compressed and discharged by the compressor 210 passes through the four-way valve 220 and flows into the indoor heat exchanger 110. The gas refrigerant condenses and liquefies, for example, by exchanging heat with the air of the air-conditioned space in the process of passing through the indoor heat exchanger 110. The condensed and liquefied refrigerant passes through the expansion valve 120. The refrigerant is decompressed when passing through the expansion valve 120. The refrigerant that is decompressed by the expansion valve 120 and becomes a gas-liquid two-phase state passes through the outdoor heat exchanger 230. In the outdoor heat exchanger 230, the refrigerant that evaporates and gasifies by exchanging heat with the outdoor air sent from the outdoor fan 240 passes through the four-way valve 220 and is sucked into the compressor 210 again. As described above, the refrigerant of the air conditioning apparatus circulates to perform air conditioning related to heating.

[0048] Next, the cooling operation will be described. The high-temperature and high-pressure gas refrigerant compressed and discharged by the compressor 210 passes through the four-way valve 220 and flows into the outdoor heat exchanger 230. Then, the refrigerant that has been condensed and liquefied by heat exchange with the outdoor air supplied by the outdoor fan 240 in the outdoor heat exchanger 230 passes through the expansion valve 120. The refrigerant is decompressed when passing through the expansion valve 120. The refrigerant that has been decompressed by the expansion valve 120 and has become a gas-liquid two-phase state passes through the indoor heat exchanger 110. Then, in the indoor heat exchanger 110, for example, the refrigerant that has evaporated and gasified by heat exchange with the air of the air-conditioned space passes through the four-way valve 220 and is sucked into the compressor 210 again. As described above, the refrigerant of the air conditioning device circulates to perform air conditioning related to cooling.

[0049] As described above, when the heat exchanger 10 functions as an evaporator, the surfaces of the flat heat transfer tubes 1 and the corrugated fins 2 are lower in temperature than the air passing through the heat exchanger 10. Therefore, moisture in the air condenses on the surfaces of the flat heat transfer tubes 1 and the corrugated fins 2, and condensed water 4 is deposited.

[0050] The condensed water 4 condensed on the surface of each fin 21 of the corrugated fin 2 flows to the drainage slits 23 and flows down toward the lower fin 21. At this time, in the area where the amount of condensed water 4 is large, the condensed water 4 easily flows on the surface of the fin 21 and easily flows down through the drainage slits 23. On the other hand, in the area where the amount of condensed water 4 is small, the condensed water 4 is retained on the surface of the fin 21, easily stays, and is difficult to flow.

[0051] Figure 4 It is a diagram for explaining the positional relationship between the drainage slits in each fin of the corrugated fin according to the first embodiment. Figure 4 (a)~ Figure 4 (e) respectively represent Figure 1 Schematic diagrams of the fins 21 at the positions shown in (a) to (e).

[0052] As described above, in the heat exchanger 10 of Embodiment 1, the horizontal position of a certain drainage slit 23 is formed to be offset from the drainage slit 23 of the fin 21 adjacent in the height direction. Although not particularly limited, in the heat exchanger 10 of Embodiment 1, drainage slits 23 having the same slit center position appear periodically in one corrugated fin 2.

[0053] Therefore, in the upper fin 21, the condensed water 4 flowing down from the ends of the drainage slits 23 in the horizontal direction falls on the lower fin 21. And the condensed water 4 falling on the lower fin 21 merges with the condensed water 4 which is difficult to flow and remains on the surface of the lower fin 21. The condensed water 4 which increases in amount due to the merging easily flows down through the drainage slits 23. Therefore, the condensed water 4 which remains on the surface of the fin 21 decreases, and it is possible to drain efficiently.

[0054] Figure 5 This is a diagram for explaining the flow of condensed water on the surface of the fin 21 of Embodiment 1. The top portion, which is the portion where the flat heat transfer tube 1 and the corrugated fin 2 are joined, is bent to narrow the interval between the fins 21. Therefore, the condensed water 4 at the top portion is held at the top portion by the surface tension generated in the condensed water 4 and is easily retained.

[0055] In the heat exchanger 10 of Embodiment 1, for example, Figure 5 As shown, the end of the drainage slit 23 in the horizontal direction can be located at the top or near the top. Figure 4 In this method, it is equivalent to Figure 4 (d) and Figure 4 (e) The position of the drainage slit 23. When the ends of the drainage slit 23 in the horizontal direction are located near the top, the condensed water 4 at the top can be merged with the condensed water 4 flowing down from the fin 21 on the upper side. The condensed water 4 at the top merges with the condensed water 4 from the fin 21 on the upper side, whereby the surface tension is destroyed and the condensed water 4 flows out from the top and flows along the fin 21 on the lower side. In addition, by locating the drainage slit 23 at both ends of the fin 21 in the horizontal direction, the drainage performance is further improved. Figure 4 In this method, it is equivalent to Figure 4 (a) Figure 4 (b) and Figure 4 (c) Position of the drainage slit 23 .

[0056] As described above, according to the heat exchanger 10 of the first embodiment, the positions of the slits in the horizontal direction of the drainage slits 23 of each fin of the corrugated fin 2 are mutually staggered in the height direction at least between the adjacent fins 21. Therefore, the condensed water 4 falling from the drainage slits 23 of the fins 21 on the upper side can be combined with the condensed water 4 that is retained on the surface of the fins 21 on the lower side and is difficult to flow, and can be drained from the drainage slits 23 of the fins 21 on the lower side. Therefore, the amount of condensed water 4 convecting on the surface of the fin 21 can be reduced, and the reduction in heat transfer performance can be suppressed. Implementation Method 2

[0057] Figure 6 This is a diagram for explaining an example of drainage slits included in the corrugated fins of the heat exchanger according to the second embodiment. Figure 6Here, the horizontal length of the drainage slit 23 and the like described in Embodiment 1 is specified. Figure 6 (a) and Figure 6 As shown in (b), the intervals between the slits may be adjusted so that the drainage slit 23 does not include the top portion formed by the flat heat transfer tube 1 and the corrugated fin 2 and does not span between two adjacent fins 21. By making the drainage slit 23 not span between two fins 21, each fin 21 has an independent drainage slit 23, and the reduction in heat transfer performance can be suppressed without reducing the contact area between the flat heat transfer tube 1 and the corrugated fin 2, and improvement in drainage performance can be expected.

[0058] Figure 7 This is a diagram for explaining another example (Part 1) of the drainage slits included in the corrugated fins of the heat exchanger according to the second embodiment. Figure 7 The corrugated fin 2 is shown in the state of the plate before corrugation. Figure 7 As shown, the horizontal dimension of the drain slit 23 may be longer than the horizontal dimension L1 of the fin 21. In this case, the drain slit 23 is formed to span between two adjacent fins 21 including the top.

[0059] Figure 8 This is a diagram for explaining another example (Part 2) of the drainage slits included in the corrugated fins of the heat exchanger according to the second embodiment. Figure 8 The corrugated fin 2 is shown in a state of a plate material before corrugation. Figure 8 The drainage slit 23 can also be connected with Figure 7 The drainage slits 23 shown are opposite, and the dimension L2 of the drainage slits 23 in the horizontal direction is shorter than the dimension L1 of the fin 21 in the horizontal direction. Figure 8 In the embodiment, the distance L3 between the drainage slits 23 of two adjacent fins 21 is formed at equal intervals. Therefore, in the horizontal direction of the fin 21, in the region including the drainage slits 23, a region where drainage is performed by the drainage slits 23 and a region where heat transfer is performed by the fin 21 can be formed, so that drainage performance can be improved and reduction in heat transfer performance can be suppressed. In addition, when the corrugated fin 2 is manufactured by corrugating the plate material, the strength of each fin 21 can be ensured to be high.

[0060] Fig. 9 This is a diagram for explaining another example (Part 3) of the drainage slits included in the corrugated fins of the heat exchanger according to the second embodiment. Fig. 9 The corrugated fin 2 is shown in the state of a plate material before corrugation. Fig. 9In the corrugated fin 2, the spacing dimension L3 between the drainage slits 23 of each of the plurality of fins 21 is different from that of the adjacent fins 21. By making the spacing dimension L3 between the drainage slits 23 of the plurality of fins 21 different from that of the adjacent fins 21, the drainage performance and the heat transfer performance can be balanced based on the design.

[0061] Fig.10 This is a diagram for explaining another example (Part 4) of the drainage slits included in the corrugated fins of the heat exchanger according to the second embodiment. Fig.10 The corrugated fin 2 is shown in a state of a plate material before corrugation. Fig.10 The corrugated fin 2 has different sizes L2 of the drainage slits 23 in the horizontal direction in the plurality of fins 21. In the corrugated fin 2, by making the sizes L2 of the drainage slits 23 in the horizontal direction different in the plurality of fins 21, drainage and heat transfer performance can be balanced by design.

[0062] Here, the intervals between the drainage slits 23 on each fin 21 of the corrugated fin 2 may be equal, or may be as follows: Fig. 9 and Fig.10 As shown, the interval of the drainage slits 23 is changed to be periodically the same. When the interval of the drainage slits 23 is made equal or the interval changes are periodically the same, the drainage slits 23 and the louvers 22 of the corrugated fin 2 can be formed by using a corrugated hole roller or a corrugated cutter (roller) or the like. By using a corrugated hole roller or the like, the processing speed when manufacturing the corrugated fin 2 can be increased. Implementation 3

[0063] Fig.11 This is a diagram for explaining the corrugated fins of the heat exchanger according to the third embodiment. Fig.11 Indicates the fin 21 where the corrugated fin 2 is located. Fig.11 As shown, in Embodiment 3, there are flat heat transfer tubes 1 arranged in a row along a planar outer surface in the depth direction. Fig.11 , an example in which the flat heat transfer tubes 1 are arranged in two rows is shown. Here, the flat heat transfer tubes 1 on the upwind side are referred to as flat heat transfer tubes 1A, and the flat heat transfer tubes 1 on the downwind side are referred to as flat heat transfer tubes 1B. Furthermore, the dimension between the two ends in the long side direction of the flat heat transfer tube 1A is referred to as L4, and the dimension between the two ends in the long side direction of the flat heat transfer tube 1B is referred to as L5. The dimension L4 and the dimension L5 may be the same length or different lengths.

[0064] The corrugated fins 2 of the heat exchanger 10 of the third embodiment are arranged across the flat heat transfer tubes 1A and 1B, and are brazed and joined to the flat heat transfer tubes 1A and 1B. Each fin 21 of the corrugated fin 2 is provided with a first drainage slit 23A within the range of both ends in the long side direction of the flat heat transfer tube 1A, and a second drainage slit 23B within the range of both ends in the long side direction of the flat heat transfer tube 1B.

[0065] Fig.12 2 is a diagram showing the state of the corrugated fin before corrugation processing according to Embodiment 3. Fig.12 As shown, in Fig.11 In the corrugated fin 2, the positions of the first drain slit 23A and the second drain slit 23B in the horizontal direction of each fin 21 are the same.

[0066] Fig.13 This is a diagram for explaining another example (part 1) of the corrugated fins of the heat exchanger according to the third embodiment. Fig.14 This is a diagram showing a state of a corrugated fin before corrugation according to another example of the third embodiment. Fig.14 The corrugated fin 2 is shown in the state of a plate material before corrugation. Fig.13 and Fig.14 In the fin 21 of the corrugated fin 2 shown, the first drain slit 23A and the second drain slit 23B are positioned differently in the horizontal direction and are offset from each other.

[0067] Fig.15 This is a diagram for explaining another example (Part 2) of the corrugated fin of the heat exchanger according to the third embodiment. Fig.15 The corrugated fin 2 is shown in the state of a plate material before corrugation. Fig.15 In the fins 21, the number of slits including the top and spanning two adjacent fins 21 is increased for the first drainage slits 23A located on the upwind side. On the other hand, the number of slits spanning two fins 21 is reduced for the second drainage slits 23B located on the leeward side.

[0068] In this way, by adjusting the interval between the first drainage slit 23A and the second drainage slit 23B between the fins 21 and the slit length, etc., the drainage performance can be improved on the upwind side of the fin 21 where the heat transfer performance is higher than that on the downwind side. In addition, the heat transfer performance can be improved even on the downwind side where the heat transfer performance is lower than that on the upwind side. Therefore, it is possible to suppress the reduction of drainage performance and heat transfer performance. In addition, by improving the heat transfer performance on the downwind side, the difference in heat transfer performance on the fin 21 can be reduced. Therefore, under low temperature air conditions, the thickness of frost formed on the surface of the fin 21 can be made nearly uniform, and the heat exchange performance under low temperature air conditions can be improved.

[0069] Here, there is no particular limitation on the position of the drainage slit 23 in the depth direction. Fig.11 and Fig.13 As shown, by arranging the depth direction position of the drainage slit 23 at a position surrounded by the louver 22 having high heat transfer performance, drainage can be performed without impairing the heat transfer performance of the louver 22 .

[0070] As described above, according to Embodiment 3, in the heat exchanger 10 in which the flat heat transfer tubes 1 are arranged in a plurality of rows in the depth direction along the flow of the passing air, the drainage slits 23 are respectively arranged between the two ends in the long side direction of the flat heat transfer tubes 1 in each row. Therefore, in this case, by adjusting the interval and the slit length of the first drainage slits 23A and the second drainage slits 23B in each row, a combination of slits that suppresses the reduction of drainage and heat transfer performance can be obtained. Implementation 4

[0071] Fig.16 This is a diagram for explaining the position of the drain slits of the heat exchanger according to Embodiment 4. In Embodiment 4, the third drain slits 23C are provided between the flat heat transfer tubes 1A and 1B, which are not joined to the flat heat transfer tubes 1A and 1B, in the depth direction of each fin 21. By providing the third drain slits 23C between the flat heat transfer tubes 1A and 1B, it is possible to improve the drainage of the area with low heat transfer performance. Implementation method 5

[0072] Fig.17 This is a diagram for explaining the positions of the drain slits of the heat exchanger according to Embodiment 5. In Embodiment 5, among the plurality of corrugated fins 2 in the heat exchanger 10, the drain slits 23 of the fins 21 located at the same position in the height direction are arranged so that the center positions of the slits in the horizontal direction are shifted from each other.

[0073] Fig.17 The center positions of the first drain slits 23Aa to 23Ac in the horizontal direction of the corrugated fins 2a to 2c shown are mutually offset. The center positions of the second drain slits 23Ba to 23Bc and the third drain slits 23Ca to 23Cc are also mutually offset. By forming a configuration in which the center positions of the drain slits 23 in the horizontal direction are mutually offset between the plurality of corrugated fins 2, the drainage performance of the entire heat exchanger 10 can be improved. Implementation 6

[0074] Fig.18 This is a diagram for explaining an example of a method for manufacturing the corrugated fin according to the sixth embodiment. Fig.18An example of a punching roller 500 used for manufacturing the corrugated fin 2 of Embodiments 1 to 5 is shown. The punching roller 500 forms drainage slits 23 on a plate to be the corrugated fin 2. For example, when a plate to be the corrugated fin 2 is supplied between a first roller cutter 501 and a second roller cutter 502 arranged in the up-down direction, a through hole to be the drainage slit 23 can be formed on a portion of the plate by the engagement between the rollers. By making the intervals in the rotation direction of the engagement portion between the rollers of the cutter having the processed plate different, drainage slits 23 with different intervals in the horizontal direction are formed on the processed plate. One rotation of the first roller cutter 501 and the second roller cutter 502 is defined as one cycle, as described above. Fig. 9 or Fig.10 As shown, the intervals of the drainage slits 23 change periodically in the same manner. Here, if the circumferential length of the roller is longer than the length of the corrugated fin 2, the intervals of all the drainage slits 23 in the corrugated fin 2 can also be processed to be different. In this way, by forming the drainage slits 23 of the corrugated fin 2 using the perforated roller 500, the processing speed when manufacturing the corrugated fin 2 can be increased. Description of Reference Numerals

[0075] 1, 1A, 1B flat heat transfer tube, 2, 2a, 2b, 2c corrugated fin, 3, 3A, 3B header, 4 condensed water, 10 heat exchanger, 21 fin, 22 louver, 23 drainage slit, 23A, 23Aa, 23Ab, 23Ac first drainage slit, 23B, 23Ba, 23Bb, 23Bc second drainage slit, 23C, 23Ca, 23Cb, 23Cc third drainage slit, 100 indoor unit, 110 indoor heat exchanger, 120 expansion valve, 130 indoor fan, 200 outdoor unit, 210 compressor, 220 four-way valve, 230 outdoor heat exchanger, 240 outdoor fan, 300 gas refrigerant piping, 400 liquid refrigerant piping, 500 opening roller, 501 first roller cutter, 502 second roller cutter.

Claims

1. A heat exchanger, The heat exchanger has: A plurality of flat heat transfer tubes, each having a flat cross-section and planar outer surfaces arranged facing each other in a horizontal direction, wherein the interior of the tubes serves as a flow path for a fluid; and The corrugated fin has a wave shape formed by bending a plate, and is arranged between the opposing flat heat transfer tubes. The top of the wave shape is connected to the flat heat transfer tube, and the space between the tops becomes a fin. The fins are arranged in the height direction, and the intervals between the fins are narrowed by bending at the top. in, Each of the fins has a drainage slit for draining water on the fin, and the positions of the ends of the drainage slits of the fins connected in the height direction via the top are located at different positions in the horizontal direction, so that the condensed water falling from the drainage slits of the fins on the upper side can merge with the condensed water that is difficult to flow and is retained on the surface of the fins on the lower side.

2. The heat exchanger according to claim 1, wherein: The fins include fins in which the ends of the drainage slits are located at the top and fins in which the drainage slits are located at both ends.

3. The heat exchanger according to claim 1, wherein: The drainage slits are both located at two ends of the adjacent fins, and the positions of the ends of the adjacent fins are staggered in the horizontal direction.

4. The heat exchanger according to claim 1, wherein: The drainage slits included in each of the three or more fins that are different in the height direction are located at different positions in the horizontal direction.

5. The heat exchanger according to any one of claims 1 to 4, wherein: The fins have louvers, The position of the drainage slit in the depth direction, which is the flow direction of air, is located at a position surrounded by the louver.

6. A refrigeration cycle device, wherein: The refrigeration cycle device comprises the heat exchanger according to any one of claims 1 to 5.

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