Heat exchanger and refrigeration cycle device comprising said heat exchanger

Abstract

A heat exchanger according to the present invention comprises: a plurality of flat tubes that are arranged in a first direction with gaps therebetween through which air is circulated, the plurality of flat tubes extending along a second direction intersecting the first direction; and a plurality of outer fins that are disposed between adjacent flat tubes, each outer fin having a body section that contacts a flat portion of the flat tube, and a protruding part that extends in at least one direction, namely, a third direction that is the circulation direction of air from the body section and intersects the first direction and the second direction, and the protruding part protruding in the third direction from adjacent flat tubes. The body section comprises, in the third direction, a plurality of unit body sections, each having, alternately in the second direction, a first base surface that is in contact with the flat portion of the flat tube and is parallel to the flat portion of the flat tube, and a first bent portion that is bent in one direction with respect to the first base surface, namely, the first direction. Among the plurality of unit body sections, at least two adjacent unit body sections have first base surfaces and first bent portions that are offset from each other in the second direction.

Description

Heat exchanger and refrigeration cycle device equipped with the heat exchanger

[0001] The present disclosure relates to a heat exchanger including fins and flat tubes, and a refrigeration cycle device including the heat exchanger.

[0002] Conventionally, there have been heat exchangers equipped with fins and flat tubes that have improved drainage (see, for example, Patent Document 1). The heat exchanger of Patent Document 1 is a heat exchanger consisting of a plurality of flat tubes arranged in a vertical direction and heat exchange fins attached between each flat tube. The heat exchange fins are formed by bending heat transfer plates, and multiple fins are provided in the airflow direction and are staggered relative to each other. In this way, the heat exchange fins are formed by bending heat transfer plates, and multiple fins are provided in the airflow direction and are staggered relative to each other, allowing drainage between the staggered heat exchange fins. This improves the drainage performance of the heat exchanger equipped with flat tubes.

[0003] JP 2008-82619 A

[0004] In the heat exchanger of Patent Document 1, the heat exchange fins arranged in the ventilation direction are inclined in the direction in which the flat tubes are arranged side by side, but because they are sandwiched between the flat tubes, the flat tubes hinder drainage in the direction in which they are arranged side by side. As a result, drainage can only be achieved by passing through the alternately arranged heat exchange fins in a zigzag pattern in the ventilation direction, which results in poor drainage and makes it easier for re-frosting to occur during normal operation after defrosting, resulting in a deterioration of heating low-temperature performance.

[0005] The present disclosure has been made to solve the above-mentioned problems, and aims to provide a heat exchanger with improved drainage performance and a refrigeration cycle device equipped with this heat exchanger.

[0006] The heat exchanger of the present disclosure comprises a plurality of flat tubes arranged in a first direction with gaps through which air flows and extending along a second direction intersecting the first direction; a main body portion arranged between adjacent flat tubes and in contact with the flat portions of the flat tubes; and a plurality of outer fins extending from the main body portion in at least one direction of a third direction which is the air flow direction and intersecting the first direction and the second direction, and having protrusions protruding from between adjacent flat tubes in the third direction, wherein the main body portion comprises a plurality of unit main body portions in the third direction which are in contact with the flat portions of the flat tubes and have first base surfaces parallel to the flat portions of the flat tubes and first bent portions bent in one direction in the first direction relative to the first base surface, alternately in the second direction, and of the plurality of unit main body portions, at least two adjacent unit main body portions have the first base surfaces and the first bent portions offset from each other in the second direction.

[0007] A refrigeration cycle device according to the present disclosure includes the above-described heat exchanger.

[0008] In the heat exchanger and refrigeration cycle apparatus according to the present disclosure, the first base surfaces and first bends of at least two adjacent unit body parts among the plurality of unit body parts are offset from each other in the second direction. This increases the number of drainage paths in the second direction between the two adjacent unit body parts compared to when the first base surfaces and first bends of the two adjacent unit body parts are not offset from each other in the second direction. This drainage path allows water droplets that accumulate in the area between the flat tubes and the outer fins to fall along the alternating first base surfaces and first bends in the second direction, which is the direction of gravity, thereby improving drainage. Furthermore, the length of the unit body part in the third direction is shorter than the length of the unit body part (i.e., the main body part) when the main body part does not include multiple unit body parts. As a result, the amount of water droplets that accumulate in the area between the flat tubes and the outer fins is reduced, thereby improving drainage. The outer fins extend from the main body in at least one direction, which is the third direction of air flow, and have protrusions that protrude in the third direction from between adjacent flat tubes. Water droplets that accumulate in the area between the flat tubes and the outer fins flow from the main body into the protrusions, which have no barrier structure and have good drainage properties, and then fall from there in the second direction, which is the direction of gravity, thereby improving drainage.

[0009] FIG. 1 is a front schematic view showing a heat exchanger according to embodiment 1. FIG. 2 is a refrigerant circuit diagram of a refrigeration cycle apparatus equipped with the heat exchanger of FIG. 1. FIG. 3 is a perspective view of a heat exchange element of the heat exchanger according to embodiment 1. FIG. 4 is a view of the main body of the heat exchange element of the heat exchanger according to embodiment 1, viewed from the upwind side. FIG. 5 is a schematic side view of the heat exchange element of the heat exchanger according to embodiment 1. FIG. 6 is a perspective view showing a drainage path of the heat exchange element of the heat exchanger according to embodiment 1. FIG. 7 is a schematic side view of the drainage path of the heat exchange element of the heat exchanger according to embodiment 1. FIG. 8 is a perspective view of a heat exchange element of a heat exchanger according to embodiment 2. FIG. 9 is a view of the main body of the heat exchange element of the heat exchanger according to embodiment 2, viewed from the upwind side. FIG. 10 is a perspective view of a heat exchange element of a heat exchanger according to a modification of embodiment 2. FIG. 11 is a view of the main body of the heat exchange element of a heat exchanger according to a modification of embodiment 2, viewed from the upwind side. FIG. 11 is a perspective view of a heat exchange element of a heat exchanger according to embodiment 3. FIG. 12 is a schematic side view showing the drainage path of the heat exchange element of the heat exchanger according to embodiment 3.

[0010] The heat exchanger according to the first embodiment will be described below with reference to the drawings. Note that in the following drawings, including FIG. 1, the relative dimensional relationships and shapes of the components may differ from those in reality. In the following drawings, identical reference numerals denote identical or equivalent components, and this applies throughout the entire specification. To facilitate understanding, directional terms (e.g., "up," "down," "right," "left," "front," "rear," etc.) are used as appropriate. However, these terms are used merely for the sake of convenience and do not limit the arrangement or orientation of the device or components. In the specification, the positional relationships between the components, the extension directions of the components, and the arrangement directions of the components generally refer to the heat exchanger when installed and ready for use.

[0011] Embodiment 1. Figure 1 is a schematic front view showing a heat exchanger 101 according to embodiment 1. In Figure 1, the direction of refrigerant flow when the heat exchanger 101 is used as an evaporator is indicated by thick outline arrows. As shown in Figure 1, the heat exchanger 101 includes a plurality of heat exchange elements 10 arranged in a first direction D1, and a first header 40 and a second header 50 connected to ends of the plurality of heat exchange elements 10.

[0012] Fig. 2 is a refrigerant circuit diagram of a refrigeration cycle apparatus 100 equipped with the heat exchanger 101 of Fig. 1. As shown in Fig. 2, the heat exchanger 101 constitutes a part of a refrigerant circuit 100c of the refrigeration cycle apparatus 100.

[0013] In the first embodiment, the refrigeration cycle apparatus 100 is described as being applied to an air conditioner. However, the refrigeration cycle apparatus 100 can be applied to refrigeration cycle apparatuses other than air conditioners, such as refrigerators, freezers, vending machines, refrigeration systems, or water heaters.

[0014] The refrigeration cycle apparatus 100 includes a compressor 102, a heat exchanger 101, an expansion device 105, an indoor heat exchanger 104, and a flow path switching device 103. In this example, the compressor 102, the heat exchanger 101, the expansion device 105, and the flow path switching device 103 are provided in the outdoor unit 100A, and the indoor heat exchanger 104 is provided in the indoor unit 100B.

[0015] The compressor 102, the flow switching device 103, the heat exchanger 101, the expansion device 105, and the indoor heat exchanger 104 are connected to each other via refrigerant pipes to form a refrigerant circuit 100c through which a refrigerant can circulate. In the refrigeration cycle apparatus 100, when the compressor 102 operates, a refrigeration cycle is performed in which the refrigerant circulates through the compressor 102, the heat exchanger 101, the expansion device 105, and the indoor heat exchanger 104 while changing phases.

[0016] The outdoor unit 100A is provided with an outdoor fan 107 that forcibly passes outdoor air through the heat exchanger 101. The indoor unit 100B is provided with an indoor fan 106 that forcibly passes indoor air through the indoor heat exchanger 104. In the following, the outdoor fan 107 will also be referred to as a fan.

[0017] The compressor 102 draws in a low-temperature, low-pressure refrigerant, compresses the drawn refrigerant, and discharges a high-temperature, high-pressure refrigerant. The compressor 102 is, for example, an inverter compressor whose capacity, which is the amount of refrigeration per unit time, is controlled by changing the operating frequency.

[0018] The heat exchanger 101 functions as an evaporator or a condenser, and exchanges heat between the refrigerant and the outdoor air generated by the operation of the outdoor fan 107, thereby evaporating the refrigerant into a gas or condensing the refrigerant into a liquid. The heat exchanger 101 functions as an evaporator during heating operation, and as a condenser during cooling operation.

[0019] The indoor heat exchanger 104 functions as an evaporator or a condenser, and exchanges heat between the refrigerant and the indoor air generated by the operation of the indoor fan 106, thereby evaporating the refrigerant into a gas or condensing it into a liquid. The indoor heat exchanger 104 functions as a condenser during heating operation, and as an evaporator during cooling operation.

[0020] The expansion device 105 reduces the pressure of the refrigerant to expand it. The expansion device 105 is, for example, an electronic expansion valve that can adjust the opening of the expansion valve, and by adjusting the opening, the pressure of the refrigerant flowing into the indoor heat exchanger 104 is controlled during cooling operation, and the pressure of the refrigerant flowing into the heat exchanger 101 is controlled during heating operation.

[0021] The flow path switching device 103 is, for example, a four-way valve that switches the direction of the refrigerant flow to switch between cooling operation and heating operation. Note that the flow path switching device 103 may be a combination of a two-way valve and a three-way valve instead of a four-way valve.

[0022] The indoor fan 106 is provided near the indoor heat exchanger 104 and supplies indoor air to the indoor heat exchanger 104, and the rotation speed is controlled to adjust the airflow rate of the indoor fan 106. The outdoor fan 107 is provided near the heat exchanger 101 and supplies outdoor air to the heat exchanger 101, and the rotation speed is controlled to adjust the airflow rate of the outdoor fan 107.

[0023] The refrigeration cycle apparatus 100 can perform cooling operation and heating operation as normal operation. Furthermore, the refrigeration cycle apparatus 100 can perform defrosting operation to remove frost that has formed on the heat exchanger 101 during heating operation. The operation of the refrigeration cycle apparatus 100 can be switched between cooling operation and defrosting operation and heating operation. In Fig. 2, the direction of refrigerant flow during cooling operation and defrosting operation is indicated by dashed arrows, and the direction of refrigerant flow during heating operation is indicated by solid arrows.

[0024] During cooling operation of the refrigeration cycle apparatus 100, the flow path switching device 103 switches so that the refrigerant from the compressor 102 is guided to the heat exchanger 101 and the refrigerant from the indoor heat exchanger 104 is guided to the compressor 102, as shown by the dashed lines in FIG. 2 . The refrigerant compressed by the compressor 102 is sent to the heat exchanger 101. In the heat exchanger 101, the refrigerant releases heat to the outdoor air and is condensed. The refrigerant is then sent to the expansion device 105, where it is decompressed and then sent to the indoor heat exchanger 104. The refrigerant then absorbs heat from the indoor air in the indoor heat exchanger 104 and evaporates, before returning to the compressor 102. Therefore, during cooling operation of the refrigeration cycle apparatus 100, the heat exchanger 101 functions as a condenser, and the indoor heat exchanger 104 functions as an evaporator.

[0025] During heating operation of the refrigeration cycle apparatus 100, the flow path switching device 103 switches so that the refrigerant from the compressor 102 is guided to the indoor heat exchanger 104 and the refrigerant from the heat exchanger 101 is guided to the compressor 102, as shown by the solid lines in FIG. 2 . The refrigerant compressed by the compressor 102 is sent to the indoor heat exchanger 104. In the indoor heat exchanger 104, the refrigerant releases heat to the indoor air and is condensed. The refrigerant is then sent to the expansion device 105, where it is decompressed and then sent to the heat exchanger 101. The refrigerant then absorbs heat from the outdoor air in the heat exchanger 101 and evaporates, before returning to the compressor 102. Therefore, during heating operation of the refrigeration cycle apparatus 100, the heat exchanger 101 functions as an evaporator, and the indoor heat exchanger 104 functions as a condenser.

[0026] During the defrosting operation of the refrigeration cycle apparatus 100, the heating operation is interrupted, and the flow path switching device 103 is switched so as to guide the refrigerant from the compressor 102 to the heat exchanger 101 and guide the refrigerant from the indoor heat exchanger 104 to the compressor 102, as shown by the dashed lines in Fig. 2. Then, the high-temperature refrigerant compressed by the compressor 102 is sent to the heat exchanger 101, and the frost adhering to the surface of the heat exchanger 101 is melted.

[0027] FIG. 3 is a perspective view of the heat exchange element 10 of the heat exchanger 101 according to the first embodiment. FIG. 4 is a view of the main body 31 of the heat exchange element 10 of the heat exchanger 101 according to the first embodiment, viewed from the windward side. FIG. 5 is a schematic side view of the heat exchange element 10 of the heat exchanger 101 according to the first embodiment. FIG. 6 is a perspective view showing the drainage paths 61 and 62 of the heat exchange element 10 of the heat exchanger 101 according to the first embodiment. FIG. 7 is a schematic side view of the drainage paths 61 and 62 of the heat exchange element 10 of the heat exchanger 101 according to the first embodiment. Note that in FIGS. 3 and 5 to 7, the direction of refrigerant flow when the heat exchanger 101 is used as an evaporator is indicated by a thick outline arrow. Also, in FIGS. 3 and 5 to 7, the direction of air flow is indicated by a thick black arrow. The schematic configuration of the heat exchanger 101 will be described below with reference to FIGS. 1 and 3 to 7. The illustrated heat exchanger 101 is an example, and its configuration is not limited to the configuration described in the embodiment, but can be modified as appropriate within the scope of the technology related to the embodiment.

[0028] As shown in Figures 3 to 5, the heat exchange element 10 is composed of flat tubes 20 and outer fins 30. The flat tubes 20 extend in a second direction D2 that intersects with the first direction D1, and are arranged so that their tube axes are aligned with the second direction D2. The outer fins 30 are arranged between adjacent flat tubes 20. As shown in Figure 1, a gap G through which air flows is formed between adjacent flat tubes 20 in the first direction D1. Then, as shown in Figure 3, air flows in the heat exchanger 101 along a third direction D3 that intersects with the first direction D1 and the second direction D2.

[0029] In the following description, the extension direction of the heat exchange element 10 (of the flat tubes 20) shown in Figure 1, i.e., the second direction D2, is defined as the up-down direction parallel to the direction of gravity. Furthermore, the arrangement direction of the multiple heat exchange elements 10, i.e., the first direction D1, is defined as the left-right direction perpendicular to the direction of gravity. Furthermore, the third direction D3, which is parallel to the air flow direction in the heat exchanger 101, is defined as the depth direction perpendicular to the first direction D1 and the second direction D2. Note that the arrangement of the heat exchanger 101 is not limited to the above case.

[0030] 1 , one end 13a of each of the heat exchange elements 10 in the tube axis direction is connected to a first header 40. The other end 13b of each of the heat exchange elements 10 in the tube axis direction is connected to a second header 50. The first header 40 and the second header 50 are arranged with their longitudinal directions facing the arrangement direction of the heat exchange elements 10, i.e., the first direction D1. That is, the longitudinal directions of the first header 40 and the second header 50 are parallel to each other. In the following description, the first header 40 and the second header 50 may be simply referred to as headers without any distinction being made between them.

[0031] (Headers) The first header 40 and the second header 50 are cylindrical bodies with closed ends, and have spaces formed therein through which the refrigerant flows. The first header 40 and the second header 50 extend in the first direction D1, and in the example shown in Fig. 1, have a rectangular parallelepiped outer shape, and in a cross section perpendicular to the first direction D1, have a rectangular cross section with long sides in the third direction D3.

[0032] In FIG. 1 , the outer shapes of the first header 40 and the second header 50 are rectangular parallelepipeds, but this shape is not limited thereto. The outer shapes of the first header 40 and the second header 50 may be, for example, cylindrical or elliptical, and the cross-sectional shapes of the first header 40 and the second header 50 may be modified as appropriate. Furthermore, the first header 40 and the second header 50 may have a structure other than the aforementioned cylindrical body with both ends closed, such as a stack of plate-like bodies with slits formed therein. Furthermore, the first header 40 and the second header 50 may have different outer shapes or cross-sectional shapes.

[0033] The first header 40 and the second header 50 each have refrigerant flow ports 41 and 51 through which the refrigerant can flow in and out. Specifically, the refrigerant flow port 41 is provided in a wall portion constituting one end of the first header 40 in the first direction D1 (the left wall portion of the first header 40 in FIG. 1 ). The refrigerant flow port 51 is provided in a wall portion constituting one end of the second header 50 in the first direction D1 (the right wall portion of the second header 50 in FIG. 1 ). When the heat exchanger 101 functions as an evaporator, the refrigerant flow port 41 serves as a refrigerant inlet for the heat exchanger 101, and the refrigerant flow port 51 serves as a refrigerant outlet for the heat exchanger 101. When the heat exchanger 101 functions as a condenser, the refrigerant flow port 51 serves as a refrigerant inlet for the heat exchanger 101, and the refrigerant flow port 41 serves as a refrigerant outlet for the heat exchanger 101. The positions at which the refrigerant flow ports 41 and 51 are provided in the first header 40 and the second header 50 are not limited to the positions described above, and can be changed as appropriate.

[0034] Furthermore, a plurality of insertion holes (not shown) are formed in the header upper wall portion of the first header 40 located on the lower side in the heat exchanger 101, and the plurality of insertion holes are arranged in parallel in the first direction D1 to correspond to the plurality of heat exchange elements 10. The plurality of insertion holes are holes into which the lower ends 13a of the plurality of heat exchange elements 10 are inserted, and penetrate the header upper wall portion of the first header 40 in the thickness direction, i.e., in the second direction D2.

[0035] Furthermore, a plurality of insertion holes (not shown) are formed in the header lower wall portion of the second header 50 located on the upper side in the heat exchanger 101, and the plurality of insertion holes are arranged in parallel in the first direction D1 to correspond to the plurality of heat exchange elements 10. The plurality of insertion holes are holes into which the upper ends 13b of the plurality of heat exchange elements 10 are inserted, and penetrate the header lower wall portion of the second header 50 in the thickness direction, i.e., in the second direction D2.

[0036] The heat exchange elements 10 have their ends 13a and 13b inserted into the first header 40 and the second header 50, respectively, and are joined together by joining means such as brazing or adhesive.

[0037] Next, an example of the operation of the heat exchanger 101 when used as an evaporator will be described. As shown in FIG. 1 , low-pressure refrigerant in a gas-liquid two-phase state flows into the heat exchanger 101 through the refrigerant flow port 41. In the heat exchanger 101, the low-pressure refrigerant in a gas-liquid two-phase state first flows into the first header 40, where it is distributed to each of the flat tubes 20 of the multiple heat exchange elements 10 by the first header 40 and flows separately into multiple refrigerant flow paths (not shown) formed inside each flat tube 20. In the refrigerant flow paths of each flat tube 20, the low-pressure refrigerant in a gas-liquid two-phase state flows in the second direction D2 toward the second header 50 and passes through the flat tubes 20. At this time, the low-pressure refrigerant in a gas-liquid two-phase state exchanges heat with air flowing through the gaps G between adjacent flat tubes 20 via the components that make up the heat exchange element 10, releasing heat to the air and evaporating, becoming a low-pressure gaseous refrigerant. The low-pressure gaseous refrigerant from the plurality of flat tubes 20 flows into the second header 50 and merges in the second header 50. The low-pressure gaseous refrigerant that has merged in the second header 50 flows out of the heat exchanger 101 (for example, to the compressor 102 in FIG. 2 ) from a refrigerant flow port 41 provided in the second header 50.

[0038] (Heat Exchange Element 10) As shown in FIG. 3 , the flat tubes 20 are flat, perforated tubes having a cross-sectional shape that is flat in one direction, such as an oval shape, and having multiple refrigerant flow paths (not shown) formed by through-holes inside. The flat tubes 20 have a pair of flat portions 21 that face the first direction D1 and extend in the third direction D3, and a pair of curved portions 22 that are located at both ends of the flat portions 21 in the third direction D3 and curve convexly outward. As shown in FIG. 1 , the flat tubes 20 are arranged in the first direction D1 with gaps G through which air flows and extend along a second direction D2 that intersects with the first direction D1. The flat tubes 20 are extruded tubes formed by extrusion molding. However, the present invention is not limited thereto, and the flat tubes 20 may also be roll-formed tubes formed by bending a single rectangular flat plate.

[0039] 3 and 5 , the outer fin 30 has a main body portion 31 arranged between the flat portions 21 of adjacent flat tubes 20 in the first direction D1, and a pair of protrusions 32 protruding from the main body portion 31 on both sides in the third direction D3. However, this is not limited thereto, and the protrusions 32 may be provided to protrude from the main body portion 31 on only one side in the third direction D3. The main body portion 31 is brazed to the flat portions 21 of the flat tubes 20, and has a plurality of base surfaces 31 a parallel to the flat portions 21 of the flat tubes 20.

[0040] The pair of protrusions 32 have a plurality of base surfaces 32a (hereinafter also referred to as second base surfaces) parallel to the flat tubes 20 and a plurality of generally C-shaped bent portions 32b (hereinafter also referred to as second bent portions) bent in the first direction D1 relative to the base surfaces 32a. However, this is not limited thereto, and the number of base surfaces 32a and bent portions 32b may each be singular rather than plural. Furthermore, the protrusions 32 do not necessarily need to have bent portions 32b. However, providing the bent portions 32b on the protrusions 32 can increase the heat transfer area of ​​the outer fins 30, improving heat transfer performance. Furthermore, the strength of the outer fins 30 can be improved.

[0041] The bent portion 32b is bent in the negative direction of the first direction D1 (to the left in FIG. 3 ) relative to the base surface 32a, but is not limited thereto, and the bent portion 32b may be bent in the positive direction of the first direction D1 (to the right in FIG. 3 ) relative to the base surface 32a.

[0042] The main body 31 includes a plurality of unit main body portions 34 arranged in a third direction D3. The unit main body portions 34 have a plurality of base surfaces 31a (hereinafter also referred to as first base surfaces) parallel to the flat tubes 20 and a plurality of substantially C-shaped bent portions 31b (hereinafter also referred to as first bent portions) bent in a first direction D1 relative to the base surfaces 31a, and the unit main body portions 34 are arranged alternately in a second direction D2. However, this is not limited thereto, and the number of base surfaces 31a and the number of bent portions 31b may be singular rather than plural. In the first embodiment, the main body 31 includes two unit main body portions 34. In FIG. 4, the unit main body portion 34 on the windward side is shown as unit main body portion 34A, and the unit main body portion 34 on the leeward side is shown as unit main body portion 34B. However, the number of unit main body portions 34 is not limited to the above, and the main body 31 may include three or more unit main body portions 34.

[0043] The bent portion 31b is bent in the negative direction of the first direction D1 (to the left in FIG. 3 ) relative to the base surface 31a. However, this is not limited thereto, and the bent portion 31b may be bent in the positive direction of the first direction D1 (to the right in FIG. 3 ) relative to the base surface 31a. The outer fin 30 is formed by bending a single rectangular flat plate material. However, this is not limited thereto, and the outer fin 30 may be formed by connecting multiple rectangular flat plate materials.

[0044] Furthermore, the base surfaces 31 a and the bending portions 31 b of two adjacent unit main body portions 34 are offset from each other in the second direction D2. Note that it is sufficient that the base surfaces 31 a and the bending portions 31 b of two adjacent unit main body portions 34 are offset from each other in the second direction D2 even by a small amount. Furthermore, when the main body portion 31 includes three or more unit main body portions 34, it is sufficient that the base surfaces 31 a and the bending portions 31 b of at least two adjacent unit main body portions 34 are offset from each other in the second direction D2.

[0045] As described above, in the heat exchanger 101 according to the first embodiment, the base surfaces 31 a and the bent portions 31 b of two adjacent unit body portions 34 in the same outer fin 30 are offset from each other in the second direction D2. Furthermore, in the same outer fin 30, the base surface 31 a of the upwind unit body portion 34A is adjacent to the bent portion 31 b of the downwind unit body portion 34B in the third direction, and the bent portion 31 b of the upwind unit body portion 34A is adjacent to the base surface 31 a of the downwind unit body portion 34B in the third direction. Therefore, as shown in FIGS. 6 and 7 , the number of drainage paths 61 extending in the second direction D2 between two adjacent unit body portions 34 can be increased compared to when the base surfaces 31 a and the bent portions 31 b of two adjacent unit body portions 34 are not offset from each other in the second direction D2. This drainage path 61 allows water droplets that accumulate in the area between the flat tubes 20 and the outer fins 30 to fall along the base surfaces 31a and bent portions 31b, which are alternately arranged in the second direction D2, in the direction of gravity, thereby improving drainage. Furthermore, the length (L1 in FIG. 5 ) of the unit main body portion 34 in the third direction D3 is shorter than the length (L0 in FIG. 5 ) of the unit main body portion 34 (= main body portion 31) when the main body portion 31 does not include multiple unit main body portions 34 (i.e., L1 < L0). As a result, the size of water droplets that accumulate in the area between the flat tubes 20 and the outer fins 30 is reduced, thereby improving drainage. Furthermore, the outer fins 30 extend from the main body portion 31 in at least one direction of the third direction D3, which is the air flow direction, and have protrusions 32 that protrude in the third direction D3 between adjacent flat tubes 20. Water droplets that accumulate in the area between the flat tubes 20 and the outer fins 30 flow through the drainage path 62, a portion of which extends in the third direction D3 as shown in Figures 6 and 7. At this time, the water droplets flow from the main body 31 into the protruding portion 32, which has no barrier structure and has good drainage properties, and then fall from there in the second direction D2, which is the direction of gravity, thereby improving drainage properties.

[0046] As described above, the heat exchanger 101 according to the first embodiment includes a plurality of flat tubes 20 arranged in the first direction D1 with gaps G through which air flows and extending along the second direction D2 intersecting the first direction D1, a main body portion 31 disposed between adjacent flat tubes 20 and in contact with the flat portions 21 of the flat tubes 20, and protruding portions extending from the main body portion 31 in at least one direction of a third direction D3 which is the air flow direction and intersects the first direction D1 and the second direction D2, and protruding in the third direction D3 from between adjacent flat tubes 20. The main body portion 31 is in contact with the flat portion 21 of the flat tube 20 and has a plurality of unit main body portions 34 arranged in a third direction D3, the unit main body portions 34 having a first base surface parallel to the flat portion 21 of the flat tube 20 and a first bent portion bent in one direction in a first direction D1 relative to the first base surface, the first base surface and the first bent portion being offset from each other in the second direction D2.

[0047] According to the heat exchanger 101 of the first embodiment, the first base surfaces and first bends of at least two adjacent unit body portions 34 among the plurality of unit body portions 34 are offset from each other in the second direction D2. Therefore, the number of drainage paths 61 extending in the second direction D2 between the two adjacent unit body portions 34 can be increased compared to when the first base surfaces and first bends of the two adjacent unit body portions 34 are not offset from each other in the second direction D2. The drainage paths 61 allow water droplets that accumulate in the area between the flat tubes 20 and the outer fins 30 to fall along the first base surfaces and first bends that are alternately arranged in the second direction D2 into the second direction D2, which is the direction of gravity, thereby improving drainage. Furthermore, the length of the unit body portion 34 in the third direction D3 is shorter than the length of the unit body portion 34 (= the main body portion 31) when the main body portion 31 does not include a plurality of unit body portions 34. As a result, water droplets that accumulate in the area sandwiched between the flat tubes 20 and the outer fins 30 become smaller, thereby improving drainage. Furthermore, the outer fins 30 extend from the main body 31 in at least one direction of the third direction D3, which is the air flow direction, and have protrusions 32 that protrude in the third direction D3 from between adjacent flat tubes 20. Water droplets that accumulate in the area sandwiched between the flat tubes 20 and the outer fins 30 flow from the main body 31 into the protrusions 32, which have no barrier structure and have good drainage properties, and then fall from there in the second direction D2, which is the direction of gravity, thereby improving drainage.

[0048] In addition, in the heat exchanger 101 according to embodiment 1, the protrusion 32 has a second base surface parallel to the flat portion 21 of the flat tube 20 and a second bent portion bent in one direction in the first direction D1 relative to the second base surface, which are arranged alternately in the second direction D2.

[0049] In the heat exchanger 101 according to the first embodiment, the second bent portion is provided in the protrusion 32, which increases the heat transfer area of ​​the outer fins 30 and improves the heat transfer performance. Furthermore, the strength of the outer fins 30 can be improved.

[0050] The refrigeration cycle apparatus 100 according to the first embodiment includes the heat exchanger 101 described above.

[0051] The refrigeration cycle apparatus 100 according to the first embodiment can achieve the same effects as the heat exchanger 101. Furthermore, since the drainage performance of the heat exchanger 101 is improved, refrigeration is less likely to occur during normal operation after a defrosting operation. As a result, the heating low-temperature performance can be improved, and reliability can be improved.

[0052] Second Embodiment A second embodiment will be described below, but explanations of parts that overlap with those of the first embodiment will be omitted, and parts that are the same as or equivalent to those of the first embodiment will be given the same reference numerals.

[0053] The difference between the heat exchanger 101 according to the first embodiment and the heat exchanger 101 according to the second embodiment is the structure of the main body 31 of the outer fin 30 of the heat exchange element 10 .

[0054] Fig. 8 is a perspective view of the heat exchange element 10 of the heat exchanger 101 according to the second embodiment. Fig. 9 is a view of the main body 31 of the heat exchange element 10 of the heat exchanger 101 according to the second embodiment, viewed from the upwind side. In Fig. 8, the direction of refrigerant flow when the heat exchanger 101 is used as an evaporator is indicated by a thick white arrow. In Fig. 8, the direction of air flow is indicated by a thick black arrow.

[0055] 8 , the outer fin 30 has a main body portion 31 arranged between the flat portions 21 of adjacent flat tubes 20 in the first direction D1, and a pair of protrusions 32 protruding from the main body portion 31 on both sides in the third direction D3. However, this is not limited thereto, and the protrusions 32 may be provided to protrude from the main body portion 31 on only one side in the third direction D3. The main body portion 31 is brazed to the flat portions 21 of the flat tubes 20, and has a plurality of base surfaces 31 a parallel to the flat portions 21 of the flat tubes 20.

[0056] The pair of protrusions 32 have a plurality of base surfaces 32a parallel to the flat tubes 20 and a plurality of generally C-shaped bent portions 32b bent in the first direction D1 relative to the base surfaces 32a. However, this is not limited thereto, and the number of base surfaces 32a and bent portions 32b may each be singular rather than plural. Furthermore, the protrusions 32 do not necessarily need to have bent portions 32b. However, by providing the bent portions 32b on the protrusions 32, the heat transfer area of ​​the outer fins 30 can be increased, improving heat transfer performance. Furthermore, the strength of the outer fins 30 can be improved.

[0057] The bent portion 32b is bent in the negative direction of the first direction D1 (leftward in FIG. 8) relative to the base surface 32a. However, without being limited thereto, the bent portion 32b may be bent in the positive direction of the first direction D1 (rightward in FIG. 8) relative to the base surface 32a.

[0058] The main body 31 includes a plurality of unit main body portions 34 arranged in a third direction D3. The unit main body portions 34 have a plurality of base surfaces 31a parallel to the flat tubes 20 and a plurality of generally C-shaped bent portions 31b bent in a first direction D1 relative to the base surfaces 31a, and the unit main body portions 34 are arranged alternately in a second direction D2. However, this is not limited thereto, and the number of base surfaces 31a and the number of bent portions 31b may be singular rather than plural. In the second embodiment, the main body 31 includes six unit main body portions 34. Of the six unit body parts 34, from the windward side they are unit body part 34A, unit body part 34B, unit body part 34C, unit body part 34D, unit body part 34E, and unit body part 34F, but as viewed from the windward side, unit body part 34C and unit body part 34E are hidden by unit body part 34A, and unit body part 34D and unit body part 34F are hidden by unit body part 34B, so only unit body part 34A and unit body part 34B are shown in Fig. 9. However, the number of unit body parts 34 is not limited to the above, and the body part 31 may have three or more unit body parts 34.

[0059] The bent portion 31b is bent in the negative direction of the first direction D1 (to the left in FIG. 8 ) relative to the base surface 31a. However, this is not limited thereto, and the bent portion 31b may be bent in the positive direction of the first direction D1 (to the right in FIG. 8 ) relative to the base surface 31a. The outer fin 30 is formed by bending a single rectangular flat plate material. However, this is not limited thereto, and the outer fin 30 may be formed by connecting multiple rectangular flat plate materials.

[0060] Furthermore, the base surfaces 31a and bent portions 31b of the multiple unit body portions 34 are arranged in a staggered pattern. That is, the base surfaces 31a and bent portions 31b of two adjacent unit body portions 34 are offset from each other in the second direction D2, and the base surfaces 31a and bent portions 31b of the multiple unit body portions 34 are alternately offset in one direction or the other in the second direction D2 along the third direction D3. Note that it is sufficient for the base surfaces 31a and bent portions 31b of two adjacent unit body portions 34 to be slightly offset from each other in the second direction D2. By arranging the base surfaces 31a and bent portions 31b of the multiple unit body portions 34 in a staggered pattern, the number of drainage paths 61 extending in the second direction D2 between two adjacent unit body portions 34 is increased, improving drainage performance. Furthermore, the boundary layer of air flowing over the surface of the heat exchanger 101 is renewed, improving heat transfer performance. Furthermore, in the case of a staggered arrangement, distortion during manufacturing can be reduced by arranging the wires in a balanced manner within the flat tube 20, thereby improving manufacturability.

[0061] Fig. 10 is a perspective view of the heat exchange element 10 of the heat exchanger 101 according to a modification of the second embodiment. Fig. 11 is a view of the main body 31 of the heat exchange element 10 of the heat exchanger 101 according to the modification of the second embodiment, viewed from the upwind side. In Fig. 10, the direction of refrigerant flow when the heat exchanger 101 is used as an evaporator is indicated by a thick white arrow. In Fig. 10, the direction of air flow is indicated by a thick black arrow.

[0062] 10 , in a modification of the second embodiment, the main body 31 may include a plurality of unit main body portions 34, and the base surfaces 31 a and the bending portions 31 b of the plurality of unit main body portions 34 may be arranged in a stepped pattern. In this case, the base surfaces 31 a and the bending portions 31 b of two adjacent unit main body portions 34 are offset from each other in the second direction D2, and the base surfaces 31 a and the bending portions 31 b of the plurality of unit main body portions 34 are offset from each other in the same direction of the second direction D2 along the third direction D3. Note that it is sufficient that the base surfaces 31 a and the bending portions 31 b of two adjacent unit main body portions 34 are offset from each other in the second direction D2 even slightly.

[0063] In a modification of the second embodiment, the main body 31 includes six unit main bodies 34. The six unit main bodies 34 are, from the windward side, unit main body 34A, unit main body 34B, unit main body 34C, unit main body 34D, unit main body 34E, and unit main body 34F, as shown in Fig. 11. However, the number of unit main bodies 34 is not limited to the above, and the main body 31 may include three or more unit main bodies 34.

[0064] In this way, by arranging the base surfaces 31 a and the bent portions 31 b of the multiple unit body portions 34 in a stepped configuration, the number of drainage paths 61 extending in the second direction D2 between two adjacent unit body portions 34 is increased, thereby improving drainage. Furthermore, the boundary layer of the air flowing over the surface of the heat exchanger 101 is renewed, thereby improving heat transfer performance. Furthermore, in the region sandwiched between the flat tubes 20, in the stepped configuration shown in FIG. 11 , the unit body portions 34 are arranged so that the windward ends of the unit body portions 34 appear more numerous than in the staggered configuration shown in FIG. 9 . Therefore, in the stepped configuration, the boundary layer of the air flowing over the surface of the heat exchanger 101 is renewed more, thereby further improving heat transfer performance.

[0065] As described above, in the heat exchanger 101 according to embodiment 2, the main body portion 31 has three or more unit main body portions 34 arranged in the third direction D3, and the first base surfaces and first bend portions of the multiple unit main body portions 34 are arranged in a staggered pattern.

[0066] According to the heat exchanger 101 of the second embodiment, by arranging the first base surfaces and first bends of the plurality of unit body portions 34 in a staggered arrangement, the number of drainage paths 61 extending in the second direction D2 between two adjacent unit body portions 34 is increased, thereby improving drainage. Also, the boundary layer of the air flowing over the surface of the heat exchanger 101 is renewed, thereby improving heat transfer performance. Furthermore, in the case of a staggered arrangement, distortion during manufacturing is reduced by arranging the tubes in a balanced manner within the flat tubes 20, thereby improving manufacturability.

[0067] In addition, in the heat exchanger 101 according to embodiment 2, the main body portion 31 has three or more unit main body portions 34 arranged in the third direction D3, and the first base surfaces and first bend portions of the multiple unit main body portions 34 are arranged in a stepped manner.

[0068] According to the heat exchanger 101 of the second embodiment, by arranging the first base surfaces and first bent portions of the plurality of unit body portions 34 in a stepped manner, the number of drainage paths 61 extending in the second direction D2 between two adjacent unit body portions 34 is increased, thereby improving drainage. Furthermore, the boundary layer of the air flowing over the surface of the heat exchanger 101 is renewed, thereby improving heat transfer performance. Furthermore, in the stepped arrangement, when the region sandwiched between the flat tubes 20 is viewed from the upwind or downwind side, the ends of the bent portions 31 b of the unit body portions 34 in the third direction D3 are arranged in a manner that makes them appear more numerous than in a staggered arrangement. Therefore, the boundary layer of the air flowing over the surface of the heat exchanger 101 is renewed more, thereby further improving heat transfer performance.

[0069] Third Embodiment Hereinafter, a third embodiment will be described, but explanations of parts that overlap with those of the first and second embodiments will be omitted, and parts that are the same as or equivalent to those of the first and second embodiments will be denoted by the same reference numerals.

[0070] The difference between the heat exchanger 101 according to the first embodiment and the heat exchanger 101 according to the third embodiment is the structure of the main body 31 of the outer fin 30 of the heat exchange element 10 .

[0071] Fig. 12 is a perspective view of the heat exchange element 10 of the heat exchanger 101 according to the third embodiment. Fig. 13 is a side schematic view showing the drainage paths 61 to 63 of the heat exchange element 10 of the heat exchanger 101 according to the third embodiment. In Figs. 12 and 13, the direction of refrigerant flow when the heat exchanger 101 is used as an evaporator is indicated by thick white arrows. In Figs. 12 and 13, the direction of air flow is indicated by thick black arrows.

[0072] As shown in Figures 12 and 13, the outer fin 30 has a main body 31 disposed between the flat portions 21 of adjacent flat tubes 20 in the first direction D1 and a pair of protrusions 32 protruding from the main body 31 on both sides in the third direction D3. The main body 31 is brazed to the flat portions 21 of the flat tubes 20 and has multiple base surfaces 31a parallel to the flat portions 21 of the flat tubes 20. The pair of protrusions 32 has multiple base surfaces 32a parallel to the flat tubes 20 and multiple, generally C-shaped, bent portions 32b bent in the first direction D1 relative to the base surfaces 32a. However, this is not limited thereto, and the number of base surfaces 32a and bent portions 32b may each be singular rather than plural. Furthermore, the bent portions 32b may not be provided on the protrusions 32. However, providing the bent portions 32b on the protrusions 32 can increase the heat transfer area of ​​the outer fin 30 and improve heat transfer performance. Furthermore, the strength of the outer fin 30 can be improved.

[0073] The bent portion 32b is bent in the negative direction of the first direction D1 (leftward in FIG. 12 ) relative to the base surface 32a, but is not limited thereto, and the bent portion 32b may be bent in the positive direction of the first direction D1 (rightward in FIG. 12 ) relative to the base surface 32a.

[0074] The main body 31 includes a plurality of unit main body portions 34 arranged in a third direction D3. The unit main body portions 34 have a plurality of base surfaces 31a parallel to the flat tubes 20 and a plurality of generally C-shaped bent portions 31b bent in a first direction D1 relative to the base surfaces 31a, and the unit main body portions 34 are arranged alternately in a second direction D2. However, this is not limited thereto, and the number of base surfaces 31a and the number of bent portions 31b may be singular rather than plural. In the third embodiment, the main body 31 includes two unit main body portions 34. However, the number of unit main body portions 34 is not limited to the above, and the main body 31 may include three or more unit main body portions 34.

[0075] The bent portion 31b is bent in the negative direction of the first direction D1 (to the left in FIG. 12 ) relative to the base surface 31a. However, this is not limited thereto, and the bent portion 31b may be bent in the positive direction of the first direction D1 (to the right in FIG. 12 ) relative to the base surface 31a. The outer fin 30 is formed by bending a single rectangular flat plate material. However, this is not limited thereto, and the outer fin 30 may be formed by connecting multiple rectangular flat plate materials.

[0076] Furthermore, the base surfaces 31 a and the bending portions 31 b of two adjacent unit main body portions 34 are offset from each other in the second direction D2. Note that it is sufficient that the base surfaces 31 a and the bending portions 31 b of two adjacent unit main body portions 34 are offset from each other in the second direction D2 even by a small amount. Furthermore, when the main body portion 31 includes three or more unit main body portions 34, it is sufficient that the base surfaces 31 a and the bending portions 31 b of at least two adjacent unit main body portions 34 are offset from each other in the second direction D2.

[0077] Furthermore, grooves 35 extending in the second direction D2 are formed in both directions of the third direction D3 of each unit body portion 34. However, this is not limited thereto, and it is sufficient that a groove 35 extending in the second direction D2 is formed in one direction of the third direction D3 of at least one unit body portion 34 among the plurality of unit body portions 34. In this way, by forming grooves 35 extending in the second direction D2 in the third direction D3 of the unit body portion 34, it is possible to increase the number of drainage paths 63 extending in the second direction D2 shown in FIG. 13 between two adjacent unit body portions 34 or between adjacent unit body portions 34 and the protruding portion 32. These drainage paths 63 allow water droplets that accumulate in the area between the flat tubes 20 and the outer fins 30 to flow down the grooves 35 in the second direction D2, which is the direction of gravity, thereby improving drainage.

[0078] As described above, in the heat exchanger 101 according to embodiment 3, a groove 35 extending in the second direction D2 is formed in one direction of the third direction D3 of at least one of the multiple unit main body parts 34.

[0079] According to the heat exchanger 101 of the third embodiment, the number of drainage paths 63 in the second direction D2 can be increased between two adjacent unit body parts 34 or between adjacent unit body parts 34 and the protruding parts 32. These drainage paths 63 allow water droplets that accumulate in the area between the flat tubes 20 and the outer fins 30 to flow down the grooves 35 in the second direction D2, which is the direction of gravity, thereby improving drainage performance.

[0080] 10 Heat exchange element, 13a End, 13b End, 20 Flat tube, 21 Flat portion, 22 Curved portion, 30 Outer fin, 31 Main body portion, 31a Base surface, 31b Bent portion, 32 Protruding portion, 32a Base surface, 32b Bent portion, 34 Unit main body portion, 34A Unit main body portion, 34B Unit main body portion, 34C Unit main body portion, 34D Unit main body portion, 34E Unit main body portion, 34F Unit main body portion, 35 Groove, 40 First header, 41 Refrigerant flow port, 50 Second header, 51 Refrigerant flow port, 61 Drainage path, 62 Drainage path, 63 Drainage path, 100 Refrigeration cycle device, 100A Outdoor unit, 100B Indoor unit, 100c Refrigerant circuit, 101 Heat exchanger, 102 Compressor, 103 Flow path switching device, 104 indoor heat exchanger, 105 expansion device, 106 indoor fan, 107 outdoor fan.

Claims

1. A heat exchanger comprising: a plurality of flat tubes arranged in a first direction with gaps for air to flow therethrough, and extending along a second direction intersecting the first direction; a main body portion arranged between adjacent flat tubes and in contact with the flat portions of the flat tubes; and a plurality of outer fins extending from the main body portion in at least one direction of a third direction which is the air flow direction and intersects the first and second directions, and having protrusions protruding from between adjacent flat tubes in the third direction, wherein the main body portion is in contact with the flat portions of the flat tubes and comprises a plurality of unit main body portions arranged in the third direction, the unit main body portions having first base surfaces parallel to the flat portions of the flat tubes and first bent portions bent in one direction in the first direction relative to the first base surface, alternately in the second direction; and of the plurality of unit main body portions, at least two adjacent unit main body portions have the first base surfaces and the first bent portions offset from each other in the second direction.

2. The heat exchanger according to claim 1, wherein the main body portion has three or more unit main body portions in the third direction, and the first base surfaces and the first bent portions of the multiple unit main body portions are arranged in a staggered pattern.

3. The heat exchanger according to claim 1, wherein the main body portion has three or more unit main body portions in the third direction, and the first base surfaces and the first bent portions of the multiple unit main body portions are arranged in a stepped manner.

4. A heat exchanger as described in any one of claims 1 to 3, wherein a groove extending in the second direction is formed in one direction of the third direction of at least one of the plurality of unit body parts.

5. A heat exchanger according to any one of claims 1 to 4, wherein the protrusions have second base surfaces parallel to the flat portions of the flat tubes and second bent portions bent in one direction in the first direction relative to the second base surfaces, alternately arranged in the second direction.

6. A refrigeration cycle device equipped with the heat exchanger according to any one of claims 1 to 5.

Images