JP7128091B2 - Plate fin heat exchanger and plate fin tube heat exchanger - Google Patents

Description

The present disclosure relates to plate fin heat exchangers and plate fin tube heat exchangers.

A plate-fin tube heat exchanger includes a plurality of plate-shaped plate fins stacked at predetermined intervals, and a plurality of heat transfer tubes penetrating through and in thermal contact with the plurality of plate fins. ing. The heat transfer tubes are arranged in two directions, and a heat medium flows through each heat transfer tube. Gas flows between the plate fins. The inflowing gas exchanges heat with each plate fin and each heat transfer tube, and is then discharged from between the plurality of plate fins. That is, the inflowing gas is cooled or heated by heat exchange with the heat medium and discharged. Patent Literature 1 discloses an example of a plate-fin tube heat exchanger.

Japanese Patent Application Laid-Open No. 2008-232448

Among conventional plate fins, there are those having protruding structures such as slit fins and louvers. This projecting structure deflects (disturbs) the gas flowing between the fins, increases the contact area between the gas and the plate fins, and improves the efficiency of heat exchange.

On the other hand, in the plate-fin tube heat exchanger, the gas that has flowed in from the upstream side flows downstream while detouring around the heat transfer tubes. The gas that has flowed in from the upstream side forms a region (so-called dead water region) in which the flow of the gas is slow compared to the surroundings on the downstream side of the heat transfer tube. In the dead water area, the flow of gas becomes slow and the amount of gas flowing per unit time becomes smaller than that in the surrounding area. That is, the amount of heat exchanged in a dead water area is less than its surroundings, and the dead water area reduces the efficiency of heat exchange.

The present disclosure has been made in view of such circumstances. That is, an object of the present disclosure is to provide a plate fin and plate fin tube heat exchanger that can improve the efficiency of heat exchange by reducing the area of the dead water area.

A first aspect of the present disclosure is a plate fin for a heat exchanger, comprising: a fin body formed in a plate shape; At the same time, a plurality of collars forming mounting holes for the heat transfer tubes and a pair of collars adjacent to each other in the second direction among the plurality of collars straddle the throat formed between them, upstream in the first direction. a plurality of fin piece formation regions distributed from the side to the downstream side; and a plurality of plate-shaped members provided in each of the fin piece formation regions and protruding from the fin body to one side in the thickness direction of the fin body. fin pieces, wherein the plurality of rows of collars arranged in the second direction are arranged in the first direction while being displaced from each other by a predetermined distance in the second direction; along an outer edge of a corresponding one of the collars , straddling the throat and arranged from upstream to downstream in the first direction; The more downstream the collar is positioned, the more inclined it is with respect to the first direction so that the surface facing the reference surface including the central axis of the corresponding collar and extending in the first direction faces the upstream side of the first direction. The gist of it is that

The plurality of fin pieces may include first rectifying fin pieces arranged in a direction intersecting the first direction, positioned upstream in the first direction from the plurality of collars arranged in the second direction. Preferably, each said first straightening fin piece may extend parallel to said first direction. The plurality of fin pieces may include diffusion fin pieces positioned between the row of the first straightening fin pieces and the throat, and the diffusion fin pieces are oriented from the upstream side to the downstream side in the first direction. may be inclined further away from the mid-plane between said pair of collars. The plurality of fin pieces may include second rectifying fin pieces positioned downstream in the first direction with respect to the throat and arranged in a direction intersecting the first direction, and each of the second rectifying fin pieces The strip may extend parallel to said first direction. The plurality of fin strips may not be located at the intermediate plane between the pair of collars. Among the plurality of fin pieces, fin pieces that are adjacent to each other in a direction crossing the first direction and form a pair may be connected at their respective tips to form a cavity penetrating in the first direction. good too. The plurality of fin pieces and the fin body may be integrally formed by processing a single base material.

A second aspect of the present disclosure is a plate-fin tube heat exchanger comprising the plate fins according to the first aspect.

According to the present disclosure, it is possible to provide a plate-fin and plate-fin tube heat exchanger capable of improving the efficiency of heat exchange by reducing the area of the dead water area.

1 is a perspective view of a heat exchanger according to one embodiment of the present disclosure; FIG. It is a front view showing the important part of the plate fin concerning this embodiment. It is a perspective view which shows an example of the collar (fin collar) which concerns on this embodiment. It is a perspective view which shows an example of the fin piece which concerns on this embodiment. FIG. 10B is a perspective view showing an example of a slit fin as a modification of the fin piece, (b) is a cross-sectional view taken along line VB-VB in (a), and (c) is a cross-sectional view showing another example of the slit fin. FIG. 4 is a diagram for explaining the inclination of deflection fin pieces according to the embodiment with respect to the Y direction; It is a figure which shows the flow of the gas by a deflection|deviation fin piece. It is a figure which shows the flow of the gas by the 1st straightening fin piece which concerns on this embodiment, and a 1st straightening fin piece. It is a figure which shows the flow of the gas by the 2nd straightening fin piece which concerns on this embodiment, and a 2nd straightening fin piece. FIG. 3 is a diagram showing diffusion fin pieces according to the present embodiment and gas flow by the diffusion fin pieces;

Hereinafter, embodiments of the present disclosure will be described in detail based on the accompanying drawings. In addition, the same code|symbol is attached|subjected to the part which is common in each figure, and the overlapping description is abbreviate|omitted. For convenience of explanation, the three directions orthogonal to each other are referred to as the X direction (second direction), the Y direction (first direction), and the Z direction. The X direction is the arrangement direction of the heat transfer tubes 12, the Y direction is the flow direction of the gas G flowing into the heat exchanger 10 (that is, the inflow direction), and the Z direction is the extending direction of the heat transfer tubes 12 and the stacking direction of the plate fins 11. (See Figure 1).

FIG. 1 is a perspective view of a heat exchanger 10 according to this embodiment. FIG. 2 is a front view showing the essential parts of the plate fins 11 according to this embodiment. As shown in FIG. 1 , the heat exchanger 10 is a plate-fin tube heat exchanger, and includes a plurality of plate fins 11 and a plurality of heat transfer tubes 12 .

As shown in FIG. 1 , the gas G to be heat-exchanged flows in the Y direction and flows between the plurality of plate fins 11 . After that, the gas G is discharged from between the plate fins 11 . The gas G passing through the heat exchanger 10 is, for example, gas discharged from a compressor (not shown). Such gas is heated as it is compressed by a compressor (not shown), and the heat exchanger 10 cools the gas G by heat exchange with the heat medium M.

The heat transfer tubes 12 extend in the Z direction and pass through the plurality of plate fins 11 . Rows 12R of heat transfer tubes 12 arranged in the X direction are arranged in the Y direction while being shifted from each other by a predetermined distance in the X direction. In the present embodiment, the heat transfer tubes 12 are arranged in a grid pattern of rectangles or squares in the XY plane (that is, located at each vertex of the rectangle), and the heat transfer tubes 12 are also placed at the center position of each rectangle or each square. They are arranged and each heat transfer tube 12 has a structure extending in the Z direction. The heat transfer tubes 12 are inserted into the mounting holes 16 of the plate fins 11 and are in thermal contact with the plate fins 11 via collars (fin collars) 14 forming the mounting holes 16 . A heat medium M flows through the heat transfer tubes 12 . The flow direction of the heat medium M in each heat transfer tube is arbitrary and may be the same or different.

The plate fins 11 are stacked in the Z direction with a predetermined interval (for example, 1 mm to several mm). As shown in FIG. 2 , the plate fin 11 includes a fin body 13 , a collar 14 , a fin piece forming region 15 and a plurality of fin pieces 20 .

The fin main body 13 is a plate-shaped heat transfer member that extends (develops) approximately along the XY plane, and defines the overall shape (that is, the outer shape) of the plate fin 11 . The thickness of the fin body 13 is thin, for example 0.15 mm. The fin body 13 is made of a metal (alloy) material having relatively high thermal conductivity and ductility suitable for press working. Such materials are for example copper or aluminium.

A collar 14 is provided on the fin body 13 . The collars 14 are arranged in the X direction (second direction). Further, the rows 14R of the collars 14 arranged in the X direction are arranged in the Y direction while being shifted from each other by a predetermined distance in the X direction. The value of this predetermined distance is, for example, 1/2 of the pitch (interval) P between the centers of two heat transfer tubes 12 adjacent to each other in the X direction (see FIGS. 1 and 2).

FIG. 3 is a perspective view showing an example of the collar 14 according to this embodiment. The collar 14 forms a mounting hole (insertion hole) 16 for the heat transfer tube 12 . The heat transfer tube 12 is inserted through the mounting hole 16 , and the inner peripheral surface of the collar 14 contacts the outer peripheral surface of the heat transfer tube 12 . That is, each collar 14 is a cylindrical wall having an inner dimension (inner diameter) substantially the same as the outer dimension (outer diameter) of the heat transfer tube 12 , and defines the position of the heat transfer tube 12 with respect to the fin body 13 .

Of the plurality of collars 14, a pair of collars 14, 14 that are adjacent to each other in the X direction will be considered. A pair of collars 14, 14 form a throat 17 therebetween. The throat 17 is a portion where the width in the X direction is the narrowest in the flow path of the gas G along the Y direction. That is, the position on the plane connecting the central axes of the openings of the collars 14,14. Therefore, the Y direction component of the flow velocity of the gas G becomes maximum around the throat 17 .

The fin formation regions 15 are distributed from the upstream side to the downstream side in the Y direction so as to straddle the throat 17 described above. The fin formation regions 15 of the present embodiment extend upstream in the Y direction and downstream in the Y direction from the collars 14 , 14 . A plurality of fin pieces 20 are provided in the fin piece formation region 15 . That is, the fin piece formation area 15 defines the area in which the fin piece 20 is formed. As described above, in the present embodiment, some of the fin pieces 20 extend to a position on the upstream side of the collars 14, 14 in the Y direction or to a position on the downstream side of the collars 14, 14 in the Y direction. It is stretched. The plurality of fin pieces 20 are arranged, for example, in the Y direction and the X direction. The plurality of fin pieces 20 are provided symmetrically with respect to an intermediate plane 18 extending in the YZ direction between the pair of collars 14 in the fin formation region 15 . An intermediate plane 18 is equidistant from each collar 14 .

The collars 14 and the fin forming regions 15 are alternately arranged in the X direction and the Y direction. In other words, a plurality of rows formed by a plurality of collars 14 and a plurality of fin forming regions 15 along the X direction are provided at intervals in the Y direction, and the collars 14 and fin forming regions 15 in each row are They are provided so as to be alternately arranged in the Y direction. The collars 14 (fin piece forming regions 15) in each adjacent row are shifted in the X direction by, for example, 1/2 of the pitch (interval) P between the centers of two collars 14 adjacent to each other in the X direction.

FIG. 4 is a perspective view showing an example of the fin piece 20 according to this embodiment. As shown in this figure, the fin piece 20 protrudes from the fin body 13 to one side in the thickness direction of the fin body 13 . Therefore, in each of the laminated plate fins 11, the fin pieces 20 protrude in the same direction. Moreover, the fin piece 20 is formed in plate shape. In this embodiment, the fin piece 20 protrudes from the fin body 13 in the Z direction and extends in the Y direction. The direction in which the fin pieces 20 protrude is not limited to the direction parallel to the Z direction, and may be inclined with respect to the Z direction. Similarly, the extending direction of the fin pieces 20 described above is not limited to the direction parallel to the Y direction. In other words, the fin piece 20 may extend from the upstream side toward the downstream side in the Y direction.

The fin piece 20 is formed by, for example, cutting and bending (lancing) the fin body 13 . That is, the plurality of fin pieces 20 and the fin body 13 may be integrally formed by processing a single base material. In this case, workability of the plate fins 11 is improved.

FIG. 4 shows an example in which two fin pieces 20 are formed by cutting and raising the fin body 13 . In this example, an opening 21 opening in the Z direction is formed between the two fin pieces 20,20.

FIG. 5 is a perspective view showing an example of a slit fin 23 as a modified example of the fin piece 20, (b) is a VB-VB sectional view in (a), and (c) is another example of the slit fin 23. It is a sectional view showing. As described above, the plurality of fin pieces 20 are provided in the fin piece formation region 15 . Of these fin pieces 20, fin pieces 22, 22 that are adjacent to each other in a direction crossing the Y direction (for example, the X direction) and form a pair may be connected at their tips 20a. In this case, the pair of fin pieces 22, 22 form a so-called slit fin 23 (at least the side surface (outer side surface) of the slit fin 23) and form a cavity 25 penetrating in the Y direction. The slit fins 23 are also called "cut-and-raise".

The form of connection between the tips 20a, 20a of the paired fin pieces 22, 22 is appropriately selected according to the interval between the fin pieces 22, 22 and the inclination angle of the fin pieces 22, 22 with respect to the fin main body 13. be. That is, as shown in FIG. 5(b), the two tips 20a, 20a may be connected via a flat portion 24 interposed therebetween, or may be directly connected as shown in FIG. 5(c). good. The inclination angle of each fin piece 22 with respect to the fin body 13 of this embodiment is 90° or less.

When the tips 20a, 20a of the fin pieces 22, 22 are connected, it is possible to suppress the flow of the gas G away from the fin main body 13, thereby suppressing deterioration of heat exchange efficiency. Also, the connection between the tips 20a, 20a can increase the mechanical strength of the fin body 13 as a whole. Furthermore, when applying the cut-and-raise process described above, the manufacturing process of the fin body 13 is simplified.

As shown in FIG. 2, the plurality of fin pieces 20 includes deflection fin pieces 20A. In other words, a part of the plurality of fin pieces 20 is configured by the deflection fin pieces 20A. The deflection fin pieces 20A are arranged from the upstream side to the downstream side in the Y direction (first direction) along the outer edge (peripheral surface) 14a of the corresponding collar 14 among the plurality of collars 14 . In other words, the deflection fin pieces 20A are arranged from the upstream side to the downstream side in the Y direction (first direction) along the outer edge 14a of the closest collar 14 among the plurality of collars 14 . Alternatively, one side surface (fin piece 20) of the two side surfaces (fin piece 20) aligned in the X direction in the slit fin (cut and raised) 23 faces the collar 14 and has a structure equivalent to that of the deflection fin piece 20A. Configure. Further, on the downstream side from the throat 17, the distance in the X direction between the deflecting fin piece 20A located on the opposite side of the intermediate surface 18 is increased toward the downstream side.

The deflection fin piece 20A is provided in the first area 15A within the fin piece forming region 15. As shown in FIG. As shown in FIG. 2, the first sections 15A are distributed along the outer edge of the collar 14 from the upstream side to the downstream side in the Y direction, and are formed by the collar 14 and third and fourth sections 15C and 15D, which will be described later. located between columns.

FIG. 6 is a diagram for explaining the inclination of the deflection fin piece 20A (the side surface of the slit fin (cut and raised) 23 facing the collar 14) with respect to the Y direction. As shown in this figure, the more downstream the deflection fin piece 20A is located in the Y direction (first direction), the more the deflection fin piece 20A faces the reference plane that includes the center axis of the corresponding collar 14 and extends in the Y direction (first direction). The surface of the deflection fin piece 20A is inclined with respect to the Y direction (first direction) so as to face the upstream side in the Y direction (first direction). In other words, the tilt angle θ of the surface of the deflecting fin piece 20A with respect to the Y direction (first direction) is such that the more downstream the fin piece 20 is positioned, the more the deflecting fin piece 20A is tilted toward the Y direction (first direction). increases toward the upstream side of the Also, the deflection fin piece 20A positioned most upstream in the Y direction has the smallest tilt angle with respect to the Y direction. Therefore, the most upstream deflecting fin piece 20A extends, for example, in parallel with the Y direction, and its inclination angle θ is 0°. That is, the deflecting fin piece 20A of this embodiment is inclined toward the facing collar side even on the upstream side of the throat 17 . Also, some of the deflecting fin pieces 20A form an aperture toward the downstream side between the facing collars. That is, for some deflection fins 20A, the distance from the facing collar is the smallest at the most downstream position of the deflection fins 20A. In this embodiment, the most upstream deflecting fin piece 20A forms a constriction toward the downstream side.

On the other hand, the most downstream deflection fin piece 20A in the Y direction has the largest tilt angle with respect to the Y direction. Also, the normal line of the most downstream deflecting fin piece 20A is inclined downstream in the Y direction with respect to the line (radius) connecting the deflecting fin piece 20A and the center 14b of the collar 14. As shown in FIG. Therefore, the most downstream deflecting fin piece 20A and the outer edge 14a of the collar 14 form a flared flow path toward the downstream side in the Y direction. When the deflection fin piece 20A constitutes one side surface of the slit fin (cut and raised) 23, the side surface (fin piece 20) on the side not facing the collar 14 may extend parallel to the Y direction.

FIG. 7 is a diagram showing the flow of the gas G through the deflection fin pieces 20A. In this figure, the flow of the gas G is indicated by solid arrows. On the other hand, the flow of the gas G when there is no deflection fin piece 20A is indicated by a dotted arrow.

As described above, the tilt angle θ of the deflecting fin piece 20A with respect to the Y direction increases as the deflecting fin piece 20A is located on the downstream side. Therefore, the more downstream the gas G flows in the Y direction, the more the gas G is deflected in the X direction by the deflecting fin piece 20A located on the downstream side. Therefore, the flow of the gas G is suppressed from being separated from the collar 14, and the gas G easily flows behind (downstream side) the collar 14 in the Y direction. That is, as indicated by the hatched area in FIG. 7, the area of the dead water area for the fluid (gas G) is made smaller than the dead water area (the area surrounded by the two-dot chain line) when there is no deflection fin piece 20A. be able to.

A reduction in the area of the dead water area means an increase in the area where heat can be exchanged between the fin bodies 13 and the heat transfer tubes 12 and the gas G. In other words, the efficiency of heat exchange in the heat exchanger 10 can be improved by installing the deflection fin pieces 20A.

Since the efficiency of heat exchange in each plate fin 11 is improved, the number of plate fins used in the heat exchanger 10 can be saved. As a result, manufacturing costs can be reduced.

FIG. 8 is a diagram showing the flow of the gas G through the first straightening fin piece 20B and the first straightening fin piece 20B according to the present embodiment. As shown in FIGS. 2 and 8, the plurality of fin pieces 20 may include first straightening fin pieces 20B. In other words, part of the plurality of fin pieces 20 may be configured by the first rectifying fin pieces 20B.

The first rectifying fin piece 20B is positioned upstream in the Y direction from the plurality of collars 14 (row of the plurality of collars 14) arranged in the X direction. Also, the first rectifying fin pieces 20B are arranged in a direction crossing the Y direction. The direction crossing the Y direction is, for example, the X direction. However, this arrangement direction is not limited to the X direction.

The first straightening fin piece 20B is provided in the second section 15B within the fin piece formation region 15 . As shown in FIG. 2 , the second sections 15B are distributed on the most upstream side in the Y direction in the fin forming regions 15 .

As shown in FIG. 8, the first straightening fin piece 20B extends parallel to the Y direction. Therefore, the first straightening fin piece 20B adjusts the flow of the gas G, which is disturbed on the upstream side of the first straightening fin piece 20B, into a flow in the Y direction. In addition, each first rectifying fin piece 20B contributes to promote uniformity of the flow rate of the gas G at each position in the X direction.

FIG. 9 is a diagram showing the flow of the gas G through the second straightening fin piece 20C and the second straightening fin piece 20C according to the present embodiment. As shown in FIGS. 2 and 9, the plurality of fin pieces 20 may include second straightening fin pieces 20C. In other words, part of the plurality of fin pieces 20 may be configured by the second straightening fin pieces 20C.

The second rectifying fin piece 20C is located downstream of the throat 17 in the Y direction. Also, the second rectifying fin pieces 20C are arranged in a direction crossing the Y direction. The direction crossing the Y direction is, for example, the X direction. However, this arrangement direction is not limited to the X direction.

The second rectifying fin piece 20C is provided in the third section 15C within the fin piece forming region 15. As shown in FIG. As shown in FIG. 2 , the third section 15C is distributed downstream of the throat 17 in the fin formation region 15 .

As shown in FIG. 9, each second straightening fin piece 20C extends parallel to the Y direction. Therefore, the second rectifying fin pieces 20C adjust the flow of the gas G, which is turbulent on the upstream side of each second rectifying fin piece 20C, into a flow in the Y direction. Thereby, the flow of the gas G can be directed to the heat transfer tubes 12 located downstream of the second rectifying fin piece 20C. That is, the gas G is more likely to collide with or approach the heat transfer tubes 12 located downstream of the second rectifying fin pieces 20C. As a result, the amount of heat exchanged between the gas G and the heat transfer tubes 12 increases, improving the efficiency of heat exchange.

FIG. 10 is a diagram showing diffusion fin pieces 20D according to this embodiment and the flow of gas G through the diffusion fin pieces 20D. As shown in FIGS. 2 and 10, the plurality of fins 20 may include diffuser fins 20D. In other words, part of the plurality of fin pieces 20 may be composed of diffusion fin pieces 20D.

The diffusion fins 20D are positioned between the row of first straightening fins 20B and the throat 17. As shown in FIG. In other words, the diffusion fin piece 20</b>D is provided in the fourth section 15</b>D within the fin formation region 15 . As shown in FIG. 2, the fourth sections 15D are distributed between the second section 15B and the third section 15C in the Y direction and between the two first sections 15A in the X direction.

As shown in FIG. 10, the diffusing fin piece 20D is inclined away from the intermediate surface 18 between the pair of collars 14, 14 as it goes from the upstream side to the downstream side in the Y direction. On the other hand, the channel width of the gas G is narrowed toward the throat 17 by the pair of collars 14 (the pair of heat transfer tubes 12 , 12 ). Therefore, the diffusion fin piece 20D deflects the flow of the gas G, which tends to concentrate toward the intermediate surface 18, in the Y direction or toward the corresponding collar 14 (heat transfer tube 12). This prevents the flow of the gas G from being excessively concentrated toward the intermediate surface 18 . Therefore, the amount of heat exchanged between the gas G and the fin bodies 13 increases, and the efficiency of heat exchange improves.

In addition, as shown in FIG. 2, the plurality of fin pieces 20 do not have to be positioned on the intermediate surface 18 . That is, the fin piece 20 provided in the fifth section 15E within the fin piece forming region 15 does not have to be positioned on the intermediate surface 18. As shown in FIG. The fifth section 15E is a section that includes the intermediate surface 18 and extends in the Y direction with a width narrower than the throat 17 . Since the fin pieces 20 in the fifth section 15E are not positioned on the intermediate surface 18, the gas G in the vicinity of the intermediate surface 18 tends to travel straight in the Y direction and easily collide with the collar 14 located downstream of the throat 17. . In this embodiment, along the intermediate surface 18 , a flow path extending in the Y direction without being blocked by the fins 20 is formed from the upstream side of the fin forming region 15 toward the downstream side of the collar 14 . there is Therefore, the efficiency of heat exchange in the heat exchanger 10 can be improved.

The present disclosure is not limited to the embodiments described above, but is indicated by the description of the scope of claims, and further includes all modifications within the meaning and scope equivalent to the description of the scope of claims. For example, the plate fins may be stacked in the Z direction so that fin pieces having the same shape are arranged in the Z direction (that is, fin pieces having the same shape overlap each other when viewed from the Z direction).

DESCRIPTION OF SYMBOLS 10... Heat exchanger, 11... Plate fin, 12... Heat transfer tube, 12R... Row, 13... Fin body, 14... Collar (fin collar), 14a... Outer edge (outer peripheral surface), 14b... Center, 14R... Row, 15 15A 1st area 15B 2nd area 15C 3rd area 15D 4th area 15E 5th area 16 Mounting hole (insertion hole) 17 Throat 18 Intermediate surface 20 Fin piece 20a Tip tip 20A, 22 Deflecting fin piece 20B First straightening fin piece 20C Second straightening fin piece 20D Diffusion fin piece 21 Opening 23 Slit fin 24 Flat portion 25 Cavity G Gas M Heat medium P Pitch

Claims (8)

A plate fin of a heat exchanger,
a main body formed in a plate shape extending in a first direction, which is an inflow direction of gas, and a second direction perpendicular to the first direction;
a plurality of collars arranged in the second direction in the main body and forming mounting holes for the heat transfer tubes;
a plurality of fin formation regions distributed from the upstream side to the downstream side in the first direction so as to straddle a throat formed between a pair of collars adjacent to each other in the second direction among the plurality of collars;
a plurality of plate-shaped fin pieces provided in each of the fin piece formation regions, protruding from the main body to one side in the thickness direction of the main body,
the rows of the plurality of colors arranged in the second direction are aligned in the first direction while being shifted from each other by a predetermined distance in the second direction;
the plurality of fin pieces include deflection fin pieces arranged from the upstream side to the downstream side in the first direction so as to straddle the throat along the outer edge of the corresponding collar among the plurality of collars;
The more downstream in the first direction the deflecting fin piece is positioned, the more upstream in the first direction the surface facing the reference surface including the central axis of the corresponding collar and extending in the first direction faces. inclined with respect to the first direction to
plate fins. the plurality of fin pieces include first straightening fin pieces arranged in a direction intersecting the first direction, positioned upstream in the first direction from the plurality of collars arranged in the second direction,
2. The plate fin according to claim 1, wherein each said first rectifying fin piece extends parallel to said first direction. the plurality of fins include diffusion fins positioned between the row of the first rectifying fins and the throat;
3. The plate fin according to claim 2, wherein said diffusing fin pieces are inclined away from an intermediate plane between said pair of collars from upstream to downstream in said first direction. The plurality of fin pieces include second rectifying fin pieces positioned downstream in the first direction with respect to the throat and arranged in a direction intersecting the first direction,
4. The plate fin according to any one of claims 1 to 3, wherein each second straightening fin piece extends parallel to the first direction. 5. A plate fin according to any one of the preceding claims, wherein said plurality of fin segments are not located in the middle plane between said pair of collars. 2. A pair of fin pieces adjacent to each other in a direction intersecting the first direction among the plurality of fin pieces are connected at their tips to form a cavity penetrating in the first direction. 6. A plate fin according to any one of 5. The plurality of fin pieces and the main body are integrally formed by processing a single base material,
A plate fin according to any one of claims 1 to 6. A plate-fin tube heat exchanger comprising the plate fins according to any one of claims 1 to 7.

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