heat exchanger

Abstract

This fin comprises a plate-shaped substrate part (10) having a heat transfer tube passing part, which is a circular shape centered on a central axis C and through which a heat transfer tube passes, and a louver part at which a first silt is formed by a first louver (21). The louver part has a flat section (16), the first louver (21) that is provided on the downstream side of the flat section (16) and protrudes more in the Z-axis direction than the flat section (16), and a second louver (22) that is provided on the downstream side of the first louver (21). The second louver (22) has a linear part (22b) at which the shape of the cross-section thereof when cut in the XZ plane is linear, a second louver upstream part (22a) bending obliquely in the upstream direction from the upstream end of the linear part (22b) and extending linearly, and a second louver downstream part (22c) bending obliquely in the downstream direction from the downstream end of the linear part (22b) and extending linearly. The linear part (22b) is disposed so as to overlap with the heat transfer tube passing part when viewing the cross-section.

Description

[Technical Field]

[0001] The present disclosure relates to a heat exchanger In a container It is related to. [Background technology]

[0002] For example, an indoor unit of an air conditioner includes a heat exchanger that exchanges heat between a refrigerant and air and a fan that sends air to the heat exchanger. The heat exchanger includes, for example, a heat transfer tube through which a refrigerant flows and fins that are provided on the outer surface of the heat transfer tube. The fan sends air to the heat transfer tube and fins, and the heat exchanger exchanges heat between the air and the refrigerant via the heat transfer tube and fins. Fins provided in such a heat exchanger are disclosed, for example, in Patent Document 1.

[0003] Patent Document 1 describes a plate fin for a heat exchanger having a plurality of tube holes formed therethrough. Reinforced regions with slits formed between the tube holes are provided. Portions of the reinforced regions separated by longitudinal slits are reinforced elements that form separate portions of a sinusoidal waveform and a lancet element that is displaced from the waveform. The lancet elements are displaced in the -y direction or the +y direction from the substrate. Opposing ends of the coupling elements are displaced in opposite directions from the substrate. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 9-166392 Summary of the Invention [Problem to be solved by the invention]

[0005] In order to improve the energy efficiency of an air conditioner (for example, its year-round energy consumption efficiency), it is effective to improve its energy efficiency when it is operated at intermediate capacity (i.e., when it is operated at half the rated capacity).When operating at intermediate capacity, the workload of the compressor is reduced, so it is important to reduce the power consumption of the fan installed in the indoor unit. However, in the fins described in Patent Document 1, the lancet element and the connecting element are all curved. This prevents the introduced air from being divided appropriately, which can increase the pressure loss of the air passing through the fins. This increase in pressure loss of the air passing through the fins can increase the power consumption of the blower that sends air to the fins.

[0006] The present disclosure has been made in view of the above circumstances, and provides a heat exchanger that can reduce pressure loss that occurs when air flows. vessel The purpose is to provide. [Means for solving the problem]

[0007] In order to solve the above problems, the heat exchanger of the present disclosure employs the following measures. A heat exchanger according to one aspect of the present disclosure is a heat exchanger that exchanges heat between a refrigerant flowing inside a heat transfer tube extending in a predetermined direction and air flowing outside the heat transfer tube in a direction intersecting the predetermined direction, the heat exchanger including heat exchanger fins attached to the heat transfer tube, the heat exchanger fins having a circular shape centered on a central axis extending in the predetermined direction and including a heat transfer tube passing portion through which the heat transfer tube passes, and a louver portion having slits formed by louvers cut and raised in the predetermined direction, the heat exchanger including a plate-like base portion provided along the air flow direction, the slits connecting one surface side and the other surface side of the base portion, the louver portion having a flat portion and a louver portion provided downstream of the flat portion and positioned further in the predetermined direction than the flat portion, and a second louver provided downstream of the first louver, wherein the second louver has a cross-sectional shape when cut along a plane formed by the predetermined direction and the air flow direction, the cross-sectional shape of the second louver has a straight portion extending in the air flow direction, an upstream portion that bends obliquely from an upstream end of the straight portion to extend in a straight line in the upstream direction, and a downstream portion that bends obliquely from a downstream end of the straight portion to extend in a straight line in the downstream direction, the straight portion being arranged so as to overlap with the heat transfer tube passing portion when viewed in the cross section, and a louver that bends in a direction opposite to the protruding direction of the upstream end of the first louver is connected to the downstream end of the flat portion, and a plurality of the heat exchanger fins are arranged side by side at predetermined intervals along the predetermined direction, Turn in the opposite direction The downstream end of the louver is Turn in the opposite direction The upstream end of the upstream portion of the second louver of the heat exchanger fin adjacent to the louver in the bending direction is located on the same plane as the upstream end of the upstream portion of the second louver of the heat exchanger fin adjacent to the louver. [Effects of the Invention]

[0008] According to the present disclosure, it is possible to reduce pressure loss that occurs when air flows. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 2 is a perspective view of a plate fin according to the first embodiment of the present disclosure. [Figure 2] FIG. 2 is a plan view showing a main part (part B) of FIG. [Figure 3] FIG. 3 is a cross-sectional view taken along the line AA in FIGS. 1 and 2. [Figure 4] FIG. 3 is an end view taken along the arrow AA in FIGS. 1 and 2. [Figure 5] FIG. 10 is a perspective view of a plate fin according to a second embodiment of the present disclosure. [Figure 6] FIG. 6 is a plan view showing a main part (part E) of FIG. 5. [Figure 7] FIG. 7 is a cross-sectional view taken along the arrow DD in FIGS. 5 and 6. [Figure 8] FIG. 7 is an end view taken along the arrows DD in FIGS. 5 and 6. DETAILED DESCRIPTION OF THE INVENTION

[0010] An embodiment of a heat exchanger fin according to the present disclosure will be described below with reference to the drawings. In the following description, the direction in which the heat transfer tubes extend will be referred to as the Z-axis direction, the air flow direction perpendicular to the Z-axis direction will be referred to as the X-axis direction, and the direction perpendicular to the Z-axis direction and the X-axis direction will be referred to as the Y-axis direction. Note that in the following description, the Z-axis direction will be described as the up-down direction, and therefore the Z-axis direction may also be referred to as the up-down direction.

[0011] [First embodiment] A first embodiment of a heat exchanger fin according to the present disclosure will be described with reference to FIGS. 1 to 4. FIG. The fin 1 according to this embodiment is a fin for a heat exchanger that is provided in a heat exchanger. The heat exchanger is provided, for example, in an indoor unit (not shown) of an air conditioner (not shown), and air is sent through it by a blower (not shown). The heat exchanger extends in the Z-axis direction (a predetermined direction) and includes a plurality of heat transfer tubes (not shown) through which a refrigerant flows. A plurality of fins 1 are provided on the outer circumferential surface of each heat transfer tube. The heat exchanger exchanges heat between the refrigerant flowing inside the heat transfer tube and the air flowing outside the heat transfer tube in the X-axis direction, via the heat transfer tubes and the fins 1. The heat transfer tubes are arranged side by side at a predetermined interval along the Y-axis direction. The heat transfer tubes are also arranged side by side in the X-axis direction, but are arranged so that adjacent heat transfer tubes do not overlap when viewed from the X-axis direction. In other words, the heat transfer tubes are arranged in a so-called staggered arrangement along the X-axis direction.

[0012] Next, the fin 1 according to this embodiment will be described in detail with reference to Figures 1 to 4. In the following description, "upstream" and "downstream" refer to the upstream and downstream in the air flow.

[0013] As shown in Fig. 3, a plurality of fins 1 are provided. The fins 1 are arranged side by side at predetermined intervals along the Z-axis direction. In the following description, the gap formed between adjacent fins 1 in the Z-axis direction is referred to as the "fin pitch P." In this embodiment, the length of the fin pitch P is defined as L1.

[0014] The fin 1 is made of a metal material (e.g., aluminum). As shown in Figures 1 and 2, the fin 1 integrally includes a plate-shaped substrate portion 10 and a cylindrical portion 30 that protrudes from the substrate portion 10 in the Z-axis direction.

[0015] The substrate 10 is a plate-shaped member. The substrate 10 is provided along the air flow direction (X-axis direction). More specifically, the substrate 10 is provided along a plane intersecting the Z-axis direction (a plane formed by the X-axis direction and the Y-axis direction). The substrate 10 is a plate-shaped member and has a predetermined thickness. The substrate 10 is manufactured, for example, by press-molding a flat plate material.

[0016] The substrate portion 10 has a plurality of heat transfer tube passage portions 11 through which heat transfer tubes pass, and a plurality of louver portions 12 in which first slits 25 etc. are formed by first louvers 21 etc. cut and raised in the Z-axis direction.

[0017] One heat transfer tube passes through each heat transfer tube passing section 11. Each heat transfer tube passing section 11 is a circular hole centered on a central axis C extending in the Z-axis direction. Each heat transfer tube passing section 11 penetrates the substrate section 10 in the plate thickness direction (Z-axis direction). As shown in FIG. 2, in this embodiment, the radius of the heat transfer tube passing section 11 is set to R1.

[0018] The heat transfer tube passing sections 11 are provided at positions corresponding to the arrangement of the heat transfer tubes. That is, the heat transfer tube passing sections 11 are arranged side by side at predetermined intervals along the Y-axis direction, similar to the heat transfer tubes, as shown in Fig. 2. In this embodiment, the distance between the central axes C of the heat transfer tube passing sections 11 adjacent to each other in the Y-axis direction is defined as D1. The heat transfer tube passing portions 11 are also arranged side by side in the X-axis direction, but are arranged so that adjacent heat transfer tube passing portions 11 do not overlap when viewed from the X-axis direction. In other words, the heat transfer tube passing portions 11 are arranged in a so-called staggered arrangement in the X-axis direction.

[0019] An annular portion 13 having an annular shape is provided around each heat transfer tube passing portion 11. The annular portion 13 is formed in a flat plate shape. The annular portion 13 is provided concentrically with the heat transfer tube passing portion 11. That is, the annular portion 13 is centered on the central axis C. A part of the outer periphery of the annular portion 13 forms the end portion of the louver portion 12 in the Y-axis direction. In this embodiment, as shown in FIG. 2, the radius of the outer periphery of the annular portion 13 is R2.

[0020] As shown in FIG. 2, two louver sections 12 are provided between heat transfer tube passage sections 11 adjacent to each other in the Y-axis direction. The two louver sections 12 are arranged side by side at a predetermined interval in the Y-axis direction. A planar dividing section 15 is provided between the louver sections 12 adjacent to each other in the Y-axis direction. The dividing section 15 is formed in a planar shape. The dividing section 15 is provided at the same height as the annular section 13. The dividing section 15 is provided over substantially the entire area of ​​the louver section 12 in the X-axis direction. In this embodiment, the length of the dividing section 15 in the Y-axis direction is defined as L2.

[0021] Louver sections 12 adjacent in the Y-axis direction are symmetrical with respect to reference plane S2. Therefore, in the following explanation, one of louver sections 12 will be explained, and an explanation of the other louver section 12 will be omitted. Reference plane S2 is a plane formed by the X-axis direction and the Z-axis direction, and is a plane that includes the center of dividing section 15 in the Y-axis direction.

[0022] 1 and 2, the louver section 12 has an upstream flat section (flat section) 16, upstream louvers 17 connected to the downstream end of the upstream flat section 16, first louvers 21 provided downstream of the upstream louvers 17, second louvers 22 provided downstream of the first louvers 21, third louvers 23 provided downstream of the second louvers 22, downstream louvers 18 provided downstream of the third louvers 23, and a downstream flat section 19 connected to the downstream end of the downstream louvers 18. The end of the louver section 12 on the heat transfer tube passing section 11 side is formed into an arc shape concentric with the heat transfer tube passing section 11.

[0023] As shown in Figures 1 and 2, the upstream flat portion 16 is provided at the end (upstream end) of the louver portion 12 in the Y-axis direction. In this embodiment, as shown in Figure 4, the length of the upstream flat portion 16 in the X-axis direction is L3. The upstream flat portion 16 is a flat member provided approximately horizontally. As shown in Figures 3 and 4, the upstream flat portion 16 has a linear cross-sectional shape when cut along a plane formed by the Z-axis direction and the X-axis direction (XZ plane). The upstream flat portion 16 is provided at the same height as the annular portion 13, the downstream flat portion 19, etc.

[0024] As shown in Figures 3 and 4, the upstream louvers 17 bend diagonally downward from the downstream end of the upstream flat portion 16 and extend downstream. In this embodiment, as shown in Figure 4, the length of the upstream louvers 17 in the X-axis direction is L4. When the upstream louvers 17 are cut along a plane formed by the Z-axis direction and the X-axis direction (the XZ plane), the cross-section of the upstream louvers 17 is linear and slopes diagonally downward. The upstream louvers 17 protrude downward from the upstream flat portion 16. The upstream louvers 17 are formed by cutting and raising a portion of a flat plate material downward.

[0025] As shown in FIGS. 3 and 4 , the cross-section of the first louvers 21 taken along a plane (XZ plane) formed by the Z-axis and X-axis directions is linearly inclined downward from the upstream end toward the downstream end. In this embodiment, as shown in FIG. 4 , the length of the first louvers 21 in the X-axis direction is L5. As shown in FIG. 3 , the first louvers 21 are arranged so that their upstream ends do not overlap with the heat transfer tube passage section 11 in the cross-section taken along a plane (XZ plane) formed by the Z-axis and X-axis directions. The first louvers 21 integrally include a first louver upstream section 21a located upstream of a center point CP in the X-axis direction and a first louver downstream section 21b located downstream of the center point CP in the X-axis direction. The downstream end of the first louver upstream section 21a and the upstream end of the first louver downstream section 21b are connected. The center point CP in the X-axis direction of the first louvers 21 is located at the same height as the upstream flat section 16, etc.

[0026] The first louver upstream portion 21a is located above the upstream flat portion 16. The first louver downstream portion 21b is located below the upstream flat portion 16. The first louver upstream portion 21a is formed by cutting and raising a portion of a flat plate material upward. The first louver downstream portion 21b is formed by cutting and raising a portion of a flat plate material downward.

[0027] As shown in Figures 3 and 4, the cross-sectional shape of the second louver 22 when cut at a plane formed by the Z-axis direction and the X-axis direction (XZ plane) has a straight portion 22b extending in the X-axis direction, a second louver upstream portion (upstream portion) 22a that bends diagonally upward from the upstream end of straight portion 22b and extends linearly in the upstream direction, and a second louver downstream portion (downstream portion) 22c that bends diagonally upward from the downstream end of straight portion 22b and extends linearly in the downstream direction.

[0028] As shown in Figures 3 and 4, the straight portion 22b is disposed so that its center in the X-axis direction is located on the central axis C. In this embodiment, as shown in Figure 4, the length of the straight portion 22b in the X-axis direction is L7. The straight portion 22b is a flat plate-like member that is disposed substantially horizontally. As shown in Figures 3 and 4, the straight portion 22b has a linear cross-sectional shape when cut along a plane formed by the Z-axis direction and the X-axis direction (XZ plane). The straight portion 22b is disposed at the same height as the annular portion 13, the upstream flat portion 16, etc.

[0029] In this embodiment, as shown in Fig. 4, the length of the second louver upstream portion 22a in the X-axis direction is L6. When the second louver upstream portion 22a is cut along a plane formed by the Z-axis direction and the X-axis direction (the XZ plane), the cross-sectional shape of the second louver upstream portion 22a is a straight line that slopes obliquely upward. The second louver upstream portion 22a protrudes upward from the straight line portion 22b. The second louver upstream portion 22a is formed by cutting and raising a portion of a flat plate-shaped material upward.

[0030] As shown in Figures 3 and 4, the second louver downstream portion 22c is symmetrical to the second louver upstream portion 22a with respect to the reference plane S1. Furthermore, as shown in Figures 3 and 4, the third louver 23 is symmetrical to the first louver 21 with respect to the reference plane S1. Furthermore, the downstream louver 18 is symmetrical to the upstream louver 17 with respect to the reference plane S1. Furthermore, the downstream flat portion 19 is symmetrical to the upstream flat portion 16 with respect to the reference plane S1. Therefore, detailed descriptions of the second louver downstream portion 22c, the third louver 23, the downstream louver 18, and the downstream flat portion 19 will be omitted. The reference plane S1 is a plane defined by the Y-axis direction and the Z-axis direction, and includes the central axis C.

[0031] As shown in FIG. 4, the cross-sectional shape of louver portion 12 is point-symmetrical on both sides of reference plane S1 with respect to center point CP of first louver 21 in the X-axis direction.

[0032] The upstream louvers 17, the first louvers 21, and the upstream portions 22a of the second louvers are arranged parallel to each other. The angle θ formed by the upstream louvers 17, the first louvers 21, the upstream portions 22a of the second louvers, and the horizontal plane is set so that the air flow passing between the fins 1 is suitably divided into two.

[0033] A first slit 25 (see FIGS. 1 and 3) is formed between the downstream end of the upstream louver 17 and the upstream end of the first louver 21. A second slit 26 (see FIGS. 1 and 3) is formed between the upstream end of the second louver 22 and the downstream end of the first louver 21. As shown in FIG. 1, the length of the first slit 25 in the Y-axis direction is longer than the length of the second slit 26 in the Y-axis direction. The first slit 25 and the second slit 26 are open in the upstream direction.

[0034] A third slit 27 (see FIG. 3) is formed between the downstream end of the second louver 22 and the upstream end of the third louver 23. Furthermore, a fourth slit 28 (see FIG. 3) is formed between the downstream end of the third louver 23 and the upstream end of the downstream louver 18. The third slit 27 and the fourth slit 28 are open to the downstream side.

[0035] The cylindrical portion 30 is a cylindrical member that stands along the edge of the heat transfer tube passage portion 11, and its lower end is connected to the substrate portion 10. The upper end of the cylindrical portion 30 abuts against the lower surface of the substrate portion 10 (more specifically, the annular portion 13) located above it.

[0036] Next, the flow of air passing through the fins 1 will be described with reference to FIG. As indicated by arrow F1 in Fig. 3, air that has flowed into fin pitch P collides with the upstream ends of first louvers 21. When the air collides with the upstream ends of first louvers 21, the air flow is divided by first louvers 21. Specifically, the air flow is divided into a flow that flows along the upper surface of first louvers 21 (see arrow F2a) and a flow that passes through first slits 25 and flows along the lower surface of first louvers 21 (see arrow F2b).

[0037] The air flowing along the upper surface of the first louver 21 passes through the second slit 26 and flows along the lower surface of the second louver 22 (see arrow F3a). The air flowing along the lower surface of the second louver 22 flows along the upper surface of the third louver 23 (see arrow F4a), and then flows along the lower surfaces of the downstream louver 18 and the downstream flat portion 19 (see arrow F5a).

[0038] On the other hand, the flow that flows along the lower surface of the first louver 21 flows along the upper surface of the second louver 22 (see arrow F3b). The flow that flows along the upper surface of the second louver 22 flows along the lower surface of the third louver 23 (see arrow F4b), and then flows along the upper surfaces of the downstream louver 18 and the downstream flat portion 19 (see arrow F5b).

[0039] In this way, the air that flows into the fin pitch P flows through two flow paths: flow path a indicated by arrows F1 and F2a to F5a, and flow path b indicated by arrows F1 and F2b to F5b. Flow path a and flow path b are flow paths that divide the fin pitch P into two equal parts.

[0040] In addition, in either flow path, the air that flows into the fin pitch P first flows downward, then changes its flow direction to flow upward near the central axis C, and continues to flow upward in a meandering manner before being discharged from the fin pitch P. In this way, in the fin 1 of this embodiment, the air changes direction only once from the time it flows into the fin pitch P until it is discharged.

[0041] According to this embodiment, the following advantageous effects are achieved. In this embodiment, the louver section 12 has a plurality of louvers (first louvers 21, second louvers 22, etc.). This causes the air flowing along the louver section 12 to meander along the plurality of louvers. Therefore, compared to when the air flows in a straight line, the contact distance between the air and the louver section 12 can be increased, thereby improving the heat transfer coefficient.

[0042] In addition, in this embodiment, the air flow is divided by the first louvers 21, thereby forming a plurality of flow paths at the fin pitch P. In this way, the air flow can be suitably divided, thereby reducing pressure loss that occurs when the air flows.

[0043] In this embodiment, the second louvers 22 provided downstream of the first louvers 21 have a straight portion 22b, a second louver upstream portion 22a, and a second louver downstream portion 22c. This makes it easier for the first louvers 21 to divide the air flow. Therefore, the air flow can be divided more effectively, and the pressure loss of the air flow can be further reduced.

[0044] In this embodiment, all the louvers (first louvers 21, second louvers 22, etc.) are formed in a straight line. This reduces the pressure loss of the circulating air compared to when the louvers are curved. Also, the louvers can be formed more easily compared to when the louvers are curved.

[0045] Furthermore, in this embodiment, planar dividing portions 15 are provided between the louver portions 12. This improves the rigidity of the louver portions 12. Therefore, the rigidity of the entire fin 1 can also be improved.

[0046] In this embodiment, the end of the louver portion 12 on the heat transfer pipe passing portion 11 side is formed in an arc shape concentric with the heat transfer pipe passing portion 11. This allows the length of the louver portion 12 to be longer on the heat transfer pipe passing portion 11 side. Therefore, more air flows can be divided, further improving the thermal conductivity.

[0047] Furthermore, in this embodiment, the first louvers 21 are arranged so that their upstream ends do not overlap the heat transfer pipe passing sections 11 in a cross section taken along a plane formed by the Z-axis direction and the X-axis direction (the XZ plane). This makes it less likely that the upstream ends of the first louvers 21 will interfere with the heat transfer pipe passing sections 11. Therefore, the length of the upper ends of the first louvers 21 that divide the air flow can be increased in the Y-axis direction, making it possible to divide a larger amount of air flow. This further improves thermal conductivity.

[0048] In addition, in this embodiment, one side of the central axis C of the louver portion 12 is point-symmetrical with respect to the center point CP of the first louver 21. This makes it possible to further reduce pressure loss that occurs when air flows.

[0049] [Second embodiment] A second embodiment of a heat exchanger fin according to the present disclosure will be described with reference to FIGS. This embodiment differs from the first embodiment in the number of first louvers and third louvers. Since other points are the same as those in the first embodiment, the same components are denoted by the same reference numerals and detailed description thereof will be omitted.

[0050] 5 and 6, the base plate portion 41 of the fin 40 according to this embodiment has two first louvers and two third louvers. In the following description, the two first louvers will be referred to as upstream first louvers 42 and downstream first louvers 43. The two third louvers will be referred to as upstream third louvers 46 and downstream third louvers 47.

[0051] As shown in Figures 7 and 8, the cross-section of the upstream first louvers 42 when cut along a plane formed by the Z-axis direction and the X-axis direction (XZ plane) is linearly inclined downward from the upstream end toward the downstream end. In this embodiment, as shown in Figure 8, the length of the upstream first louvers 42 in the X-axis direction is L8. As shown in Figure 7, the upstream first louvers 42 are arranged so that their upstream ends do not overlap with the heat transfer tube passing section 11 in the cross-section when cut along a plane formed by the Z-axis direction and the X-axis direction (XZ plane). The approximate center point of the upstream first louvers 42 in the X-axis direction is located at the same height as the upstream flat section 16, etc.

[0052] As shown in FIGS. 7 and 8, the downstream first louvers 43 are provided downstream of the upstream first louvers 42. The cross-section of the downstream first louvers 43, when cut along a plane (XZ plane) formed by the Z-axis direction and the X-axis direction, is linearly inclined downward from the upstream end to the downstream end. In this embodiment, as shown in FIG. 8, the length of the downstream first louvers 43 in the X-axis direction is L9. As shown in FIG. 7, the downstream first louvers 43 are provided so that the entirety of the downstream first louvers 43 overlaps with the heat transfer tube passage portion 11 in the cross-section when cut along a plane (XZ plane) formed by the Z-axis direction and the X-axis direction. The approximate center point of the downstream first louvers 43 in the X-axis direction is located at the same height as the upstream flat portion 16, etc.

[0053] The upstream side of the upstream first louvers 42 and the downstream first louvers 43 in the X-axis direction is located above the upstream flat portion 16. The downstream side of the upstream first louvers 42 and the downstream first louvers 43 in the X-axis direction is located below the upstream flat portion 16. The upstream side of the upstream first louvers 42 and the downstream first louvers 43 in the X-axis direction is formed by cutting and raising a portion of a flat plate material upward. The downstream side of the upstream first louvers 42 and the downstream first louvers 43 in the X-axis direction is formed by cutting and raising a portion of a flat plate material downward.

[0054] 7 and 8, the upstream-side third louvers 46 are symmetrical to the downstream-side first louvers 43 with respect to the reference plane S1. Also, the downstream-side third louvers 47 are symmetrical to the upstream-side first louvers 42 with respect to the reference plane S1. Therefore, detailed description of the upstream-side third louvers 46 and the downstream-side first louvers 43 will be omitted.

[0055] 8, the upstream louvers 17, the first upstream louvers 42, the first downstream louvers 43, and the upstream portions 22a of the second louvers are arranged in parallel. The angle θ formed by the first upstream louvers 42 and the first downstream louvers 43 and the horizontal plane is set so that the air flow passing between the fins 1 is suitably divided into two.

[0056] An upstream first slit 44 (see FIGS. 5 and 7) is formed between the downstream end of the upstream louver 17 and the upstream end of the upstream first louver 42. Further, an upstream first slit 44 is formed between the downstream end of the upstream first louver 42 and the upstream end of the downstream first louver 43. Further, a second slit 26 is formed between the upstream end of the second louver 22 and the downstream end of the downstream first louver 43. Further, as shown in FIG. 1, the length of the upstream first slit 44 in the Y-axis direction is longer than the length of the downstream first slit 45 in the Y-axis direction. Further, the length of the downstream first slit 45 in the Y-axis direction is longer than the length of the second slit 26 in the Y-axis direction. The upstream first slit 44 and the downstream first slit 45 are open in the upstream direction.

[0057] 7, an upstream-side third slit 48 is formed between the downstream end of the second louver 22 and the upstream end of the upstream-side third louver 46. A downstream-side third slit 49 is formed between the downstream end of the upstream-side third louver 46 and the upstream end of the downstream-side third louver 47. A fourth slit 28 is formed between the downstream end of the downstream-side third louver 47 and the upstream end of the downstream-side louver 18. The upstream-side third louver 46 and the downstream-side third louver 47 are open to the downstream side.

[0058] Next, the flow of air passing through the fins 1 will be described with reference to FIG. As shown by arrow F1 in Fig. 7, air that has flowed into the fin pitch P collides with the upstream ends of the upstream first louvers 42. When the air collides with the upstream ends of the upstream first louvers 42, the air flow is divided by the upstream first louvers 42. Specifically, the air flow is divided into a flow that flows along the upper surface of the upstream first louvers 42 (see arrows F2c and F2d) and a flow that passes through the upstream first slits 44 and flows along the lower surface of the upstream first louvers 42 (see arrow F2e). Note that although arrows F2c and F2d are shown as separate arrows for convenience, they actually flow together at this stage.

[0059] The air flowing along the upper surface of the upstream-side first louver 42 collides with the upstream end of the downstream-side first louver 43. When the air collides with the upstream end of the downstream-side first louver 43, the air flow is divided by the downstream-side first louver 43. Specifically, the air flow is divided into a flow that flows along the upper surface of the downstream-side first louver 43 (see arrow F2c) and a flow that passes through the downstream-side first slit 45 and flows along the lower surface of the downstream-side first louver 43 (see arrow F2d).

[0060] The air flow that flows along the upper surface of the downstream-side first louver 43 (see arrow F2c) passes through the second slits 26 and flows along the lower surface of the second louver 22 (see arrow F3c). The air flow that flows along the lower surface of the second louver 22 flows along the upper surface of the upstream-side third louver 46 and above the downstream-side third louver 47 (see arrow F4c), and then flows along the lower surfaces of the downstream-side louvers 18 and downstream-side flat portion 19 (see arrow F5c).

[0061] The air flow that flows along the lower surface of the downstream-side first louver 43 (see arrow F2d) flows below the second louver 22 (see arrow F3d). The air flow that flows below the second louver 22 flows along the lower surface of the upstream-side third louver 46 and along the upper surface of the downstream-side third louver 47 (see arrow F4d), and then flows above the downstream-side louver 18 and the downstream-side flat portion 19 (see arrow F5d).

[0062] On the other hand, the air flow that flows along the lower surface of the upstream first louver 42 (see arrow F2e) flows along the upper surface of the second louver 22 of the fin adjacent in the Z-axis direction (see arrow F3e). The air flow that flows along the upper surface of the second louver 22 flows below the upstream third louver 46 and along the lower surface of the downstream third louver 47 (see arrow F4e), and then flows along the upper surfaces of the downstream louvers 18 and the downstream flat portion 19 (see arrow F5e).

[0063] In this way, the air that flows into the fin pitch P flows through three flow paths: flow path c indicated by arrows F2c to F5c, flow path d indicated by arrows F2d to F5d, and flow path e indicated by arrows F2e to F5e. Flow path c, flow path d, and flow path e are flow paths that divide the fin pitch P into thirds.

[0064] According to this embodiment, the following advantageous effects are achieved. In this embodiment, a plurality of first louvers (upstream-side first louvers 42 and downstream-side first louvers 43) (two, in this embodiment, as an example) are provided. This allows the total length in the Y-axis direction of the upstream ends of the first louvers (the total length in the Y-axis direction of the upstream ends of all first louvers) to be longer compared to when there is only one first louver. Therefore, it is possible to divide more air flows. This further reduces the pressure loss that occurs when air flows.

[0065] Furthermore, in this embodiment, multiple first louvers (upstream-side first louvers 42 and downstream-side first louvers 43) are aligned along the X-axis direction. This allows the length of each first louver in the X-axis direction to be shorter than when only one first louver is provided. Therefore, since the first louvers are angled θ with respect to the horizontal plane, the length of each first louver in the Z-axis direction (the extension direction of the heat transfer tube) (in other words, the length of the first louvers protruding in the Z-axis direction) can be shortened. This also allows the length of the heat exchange fins themselves in the Z-axis direction to be shortened, so that when multiple fins 40 are aligned in the Z-axis direction, the fins 40 can be densely arranged. Alternatively, when the same number of fins 40 are provided, the heat exchanger provided with the fins 40 can be made more compact.

[0066] In this embodiment, the distance between the fins 40 adjacent to each other in the Z-axis direction is set to L1, the same as in the first embodiment, but may be set to a distance shorter than L1.

[0067] The present disclosure is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present disclosure. For example, the dimensions of each part of the fin 1 described in the above embodiment are merely examples and are not limited to the above-described dimensions.

[0068] Furthermore, in the first embodiment, an example in which the number of first louvers and the number of third louvers are one each has been described, and in the second embodiment, an example in which the number of first louvers and the number of third louvers are two each has been described, but the numbers of first louvers and third louvers are not limited to these. For example, the number of first louvers and the number of third louvers may be three or more. However, if the number of first louvers and the number of third louvers are too large, air resistance may increase, which may increase the pressure loss of air passing through the heat exchanger fins. Therefore, the optimal number of first louvers and the number of third louvers may be determined from the perspective of air resistance.

[0069] The heat exchanger fins according to the above-described embodiments can be understood, for example, as follows. A heat exchanger fin according to an embodiment of the present disclosure is provided in a heat exchanger that exchanges heat between a refrigerant flowing inside a heat transfer tube extending in a predetermined direction (Z-axis direction) and air flowing outside the heat transfer tube in a direction intersecting the predetermined direction (X-axis direction), and is a heat exchanger fin (1) attached to the heat transfer tube, the fin having a heat transfer tube passage portion (11) having a circular shape centered on a central axis (C) extending in the predetermined direction and through which the heat transfer tube passes, and a louver portion (12) in which slits (25) are formed by louvers (21, 22) cut and raised in the predetermined direction, and a plate-shaped base portion (10) provided along the air flow direction, the slits communicating one surface side and the other surface side of the base portion. The louver portion has a flat portion (16), a first louver (21) provided downstream of the flat portion and protruding in the specified direction beyond the flat portion, and a second louver (22) provided downstream of the first louver, and the second louver has a cross-sectional shape when cut along a plane (XZ plane) formed by the specified direction and the air flow direction, which has a straight portion (22b) extending in the air flow direction, an upstream portion (22a) that bends obliquely from the upstream end of the straight portion to extend linearly in the upstream direction, and a downstream portion (22c) that bends obliquely from the downstream end of the straight portion to extend linearly in the downstream direction, and the straight portion is arranged so as to overlap with the heat transfer tube passing portion when viewed in cross section.

[0070] In the above configuration, the louver portion has first and second louvers. This causes air flowing along the louver portion to meander along the first and second louvers. Therefore, compared to when air flows in a straight line, the contact distance between the air and the louver portion can be increased, thereby improving the heat transfer coefficient. In the above configuration, air flowing along the louver portion flows along the flat portion and then collides with the upstream end of the first louver. When the air collides with the upstream end of the first louver, the first louver divides the air flow. Specifically, the air flow is divided into a flow that flows along one surface of the louver portion and a flow that passes through the slits and flows along the other surface of the louver portion. Since the air flow is divided by the first louver in this manner, for example, when multiple fins (hereinafter, adjacent fins in the predetermined direction will be referred to as "first fin" and "second fin") are arranged at predetermined intervals in a predetermined direction, multiple air flows will be formed in the gaps formed between the first fin and the second fin. More specifically, an air flow will be formed that flows along the other surface of the first fin and an air flow will be formed that flows along one surface of the second fin. In this way, the first louver can effectively divide the air flow, thereby reducing pressure loss that occurs when the air flows. In addition, in the above configuration, the second louver provided downstream of the first louver has a straight portion, an upstream portion, and a downstream portion. The straight portion, upstream portion, and downstream portion are all formed in a straight line. This makes it easier to process compared to, for example, forming the straight portion, upstream portion, and downstream portion in a curved shape.

[0071] In addition, in the heat exchanger fin according to the embodiment of the present disclosure, the first louvers are formed linearly in the cross section.

[0072] In the above configuration, the first louvers are formed in a straight line. This reduces the pressure loss of the circulating air compared to when the first louvers are curved. Furthermore, the first louvers can be formed more easily compared to when the first louvers are curved.

[0073] Furthermore, the heat exchanger fin according to the embodiment of the present disclosure has a plurality of louver sections, which are arranged side by side in a direction intersecting the direction in which the air flows, and planar dividing sections (15) are provided between the louver sections.

[0074] In the above configuration, planar dividing portions are provided between the louver portions, which improves the rigidity of the louver portions and therefore the rigidity of the entire fin.

[0075] In the heat exchanger fin according to the embodiment of the present disclosure, the end of the louver portion on the heat transfer tube passing portion side is formed in an arc shape that is concentric with the heat transfer tube passing portion.

[0076] In the above configuration, the end of the louver portion on the heat transfer tube passage side is formed in an arc shape concentric with the heat transfer tube passage. This allows the length of the louver portion to be longer on the heat transfer tube passage side. This allows more airflow to be divided, further reducing pressure loss that occurs when the air flows.

[0077] In the heat exchanger fin according to the embodiment of the present disclosure, the first louvers are provided such that the upstream ends thereof do not overlap the heat transfer tube passing portions in the cross sections.

[0078] In the above configuration, the first louvers are arranged so that their upstream ends do not overlap the heat transfer tube passages in cross section. This reduces the likelihood of interference between the upstream ends of the first louvers and the heat transfer tube passages. This allows the length of the upstream ends of the first louvers that divide the air flow to be increased, making it possible to divide a larger amount of air flow. This further reduces pressure loss that occurs when the air flows.

[0079] Furthermore, in the heat exchanger fin according to an embodiment of the present disclosure, the cross-sectional shape of the louver portion is linearly symmetrical with respect to the central axis, and one side of the central axis is point-symmetrical with respect to the center point (CP) of the first louver.

[0080] In the above configuration, the side of the central axis of the louver portion is point-symmetrical with respect to the center point of the first louver, thereby reducing pressure loss that occurs when air flows.

[0081] Moreover, in the heat exchanger fin according to the embodiment of the present disclosure, a plurality of the first louvers (42, 43) are provided, and the plurality of first louvers are arranged side by side in the air circulation direction.

[0082] In the above configuration, multiple first louvers are provided. This allows the total length of the upstream ends of the first louvers (the sum of the lengths of the upstream ends of all the first louvers) to be longer than when there is only one first louver. This makes it possible to divide more airflow. This further reduces pressure loss that occurs when air flows. Furthermore, in the above configuration, multiple first louvers are aligned along the air flow direction. This allows the size of each first louver to be smaller than when only one first louver is used. This therefore allows the length of each first louver in a predetermined direction (the extension direction of the heat transfer tube) (in other words, the length of the first louver protruding in the predetermined direction) to be shortened. This also allows the length of the heat exchange fin itself in the predetermined direction to be shortened, so when multiple heat exchange fins are aligned in a predetermined direction, the heat exchange fins can be densely arranged. Alternatively, when the same number of heat exchange fins are provided, a heat exchanger provided with heat exchange fins of the above configuration can be made smaller. [Explanation of symbols]

[0083] 1: Fin 10: Circuit board 11: Heat transfer tube passage 12: Louver section 13: Annular part 15: Divided part 16: Upstream flat area (flat area) 17: Upstream louver 18: Downstream louver 19: Downstream flat area 21: First louver 21a: Upstream part of the first louver 21b: Downstream of the first louver 22: Second louver 22a: Upstream part of the second louver (upstream part) 22b: Straight section 22c: Downstream part of the second louver (downstream part) 23: Third louver 25: First slit 26: Second slit 27: Third slit 28: 4th slit 30: Cylindrical part 40: Finn 41: Circuit board 42: Upstream first louver 43: Downstream first louver 44: First upstream slit 45: First downstream slit 46: Upstream third louver 47: Downstream third louver 48: Third upstream slit 49: Downstream third slit

Claims

1. A heat exchanger that exchanges heat between a refrigerant flowing inside a heat transfer tube extending in a predetermined direction and air flowing outside the heat transfer tube in a direction intersecting the predetermined direction, the heat exchanger including heat exchanger fins attached to the heat transfer tube; The heat exchanger fin is a heat transfer tube passing section having a circular shape centered on a central axis extending in the predetermined direction and through which the heat transfer tube passes, and a louver section in which slits are formed by louvers cut and raised in the predetermined direction, and a plate-shaped base plate section provided along the air flow direction, the slit communicates one surface side and the other surface side of the substrate portion, the louver portion has a flat portion, a first louver provided downstream of the flat portion and protruding beyond the flat portion in the predetermined direction, and a second louver provided downstream of the first louver, the second louver has a cross-sectional shape when cut along a plane formed by the predetermined direction and the air flow direction, which has a straight portion extending in the air flow direction, an upstream portion extending in a straight line from an upstream end of the straight portion and bending obliquely in the upstream direction, and a downstream portion extending in a straight line from a downstream end of the straight portion and bending obliquely in the downstream direction, the straight portion is arranged so as to overlap the heat transfer tube passing portion when viewed in the cross section, A louver is connected to the downstream end of the flat portion, the louver being bent in a direction opposite to the protruding direction of the upstream end of the first louver, The heat exchanger fins are arranged in a plurality at predetermined intervals along the predetermined direction, A heat exchanger in which the downstream end of the louver bending in the opposite direction is located on the same plane as the upstream end of the upstream portion of the second louver of the heat exchanger fin adjacent to the louver bending in the opposite direction.

2. The heat exchanger according to claim 1 , wherein the first louvers are formed linearly in the cross section.

3. The louver portion is provided in plurality, The plurality of louver portions are arranged side by side in a direction intersecting the air flow direction, 3. The heat exchanger according to claim 1, wherein planar dividing portions are provided between the louver portions.

4. 3. The heat exchanger according to claim 1, wherein an end of the louver portion on the side of the heat transfer tube passing portion is formed into an arc shape concentric with the heat transfer tube passing portion.

5. The heat exchanger according to claim 4 , wherein the first louvers are provided so that their upstream ends do not overlap with the heat transfer tube passage portions in the cross sections.

6. A heat exchanger as described in claim 1 or claim 2, wherein the cross-sectional shape of the louver portion is linearly symmetrical with respect to the central axis, and one side of the central axis is point-symmetrical with respect to the center point of the first louver.

7. The first louvers are provided in plurality, The heat exchanger according to claim 1 or 2, wherein the plurality of first louvers are arranged side by side in the direction in which the air flows.

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