WO2023033000A1

WO2023033000A1 - Heat exchanger

Info

Publication number: WO2023033000A1
Application number: PCT/JP2022/032653
Authority: WO
Inventors: 駿作江口; 陽一上藤; 玄人市川; 優好平沢; 克弘齊藤; 博之中拂; 雄太 ▲高▼橋; 陸史亀井; 毅金子; 浩一谷本
Original assignee: 三菱重工サーマルシステムズ株式会社
Priority date: 2021-08-31
Filing date: 2022-08-30
Publication date: 2023-03-09
Also published as: JP2023035071A

Abstract

This heat exchanger comprises: a pair of plates that face each other; and an inner fin which is provided between the plates and in which a fluid circulates. The inner fin has a plurality of offset fins which are arranged side by side in the flowing direction of the fluid and are provided such that the positions thereof are mutually offset in the width direction orthogonal to the flowing direction. The offset fins include: plate joint parts which are joined to the plates and have steps formed in the flowing direction; fin parts provided along the opposing direction of the plates and connected to the plate joint parts; and reception slopes which are provided to the plate joint parts obliquely to the flowing direction and which receive the fluid from the steps.

Description

Heat exchanger

The present disclosure relates to heat exchangers.

Conventionally, heat exchangers such as oil coolers using offset fins as inner fins are known (see Patent Document 1, for example). This oil cooler includes a tube through which oil flows inside and a cooling medium through the outside, and offset fins that are arranged in the tube and perform heat exchange between the oil and the cooling medium. . The offset fin has a cross-sectional shape perpendicular to the direction of oil flow, which is a wave shape in which the convex portions are alternately positioned on one side and the other side.

JP 2012-17943 A

In a heat exchanger using offset fins, a temperature boundary layer is formed on the fin wall surfaces between the fluids passing on both sides of the offset fins where heat is exchanged between a high-temperature fluid such as oil and a low-temperature fluid such as a cooling medium. is formed. The thermal boundary layer is a layer formed by a temperature gradient between the fluid heated or cooled on the fin wall surface and the fluid near the wall surface. The thickness of the thermal boundary layer increases due to heat exchange, and when the temperature gradient in the fluid near the wall surface becomes smaller, the heat exchange is suppressed and the heat transfer performance decreases. put away.

Therefore, an object of the present disclosure is to provide a heat exchanger capable of suppressing deterioration in heat transfer performance by reducing the thickness of the temperature boundary layer.

A heat exchanger according to the present disclosure includes a pair of plates facing each other, and inner fins provided between the pair of plates and through which a fluid circulates. A plurality of offset fins are arranged side by side and offset from each other in the width direction orthogonal to the flow direction, and the offset fins are joined to the plate and formed in the flow direction. a plate joint portion having a stepped portion; a fin portion connected to the plate joint portion and provided along the facing direction of the pair of plates; and a fin portion provided at the plate joint portion and oblique to the flow direction. , and a receiving slope of the step portion that receives the fluid.

Another heat exchanger of the present disclosure includes a pair of plates that face each other, and inner fins that are provided between the pair of plates and in which a fluid flows. and a plurality of offset fins arranged side by side along the width direction perpendicular to the flow direction, wherein the offset fins are a plate joint portion joined to the plate; A fin portion connected to the plate joint portion and provided along the facing direction of the pair of plates, and a projection portion provided at the plate joint portion and protruding inward from the plate joint portion.

Another heat exchanger of the present disclosure includes a pair of plates that face each other, and inner fins that are provided between the pair of plates and in which a fluid flows. and a plurality of offset fins arranged side by side along the width direction perpendicular to the flow direction, wherein the offset fins are a plate joint portion joined to the plate; A fin portion connected to the plate joint portion and provided along the facing direction of the pair of plates, and a hole provided in the plate joint portion and recessed from the plate joint portion toward the plate side.

According to the present disclosure, it is possible to suppress the formation of a temperature boundary layer and suppress the deterioration of heat transfer performance.

FIG. 1 is a perspective view schematically showing a heat exchanger according to Embodiment 1. FIG. 2 is a perspective view showing offset fins of the heat exchanger according to Embodiment 1. FIG. FIG. 3 is a two-sided view of the offset fin. FIG. 4 is a cross-sectional view of an offset fin. FIG. 5 is an explanatory diagram regarding the flow of fluid. FIG. 6 is a perspective view showing offset fins of the heat exchanger according to Embodiment 2. FIG. FIG. 7 is a perspective view showing projections of offset fins. FIG. 8 is a two-sided view of the offset fin. 9 is a perspective view showing offset fins of a heat exchanger according to Embodiment 3. FIG. FIG. 10 is a plan view of the offset fin. FIG. 11 is a cross-sectional view of an offset fin. FIG. 12 is an explanatory diagram regarding the flow of fluid.

Hereinafter, embodiments according to the present disclosure will be described in detail based on the drawings. Note that the present disclosure is not limited by this embodiment. In addition, components in the following embodiments include components that can be easily replaced by those skilled in the art, or components that are substantially the same. Furthermore, the components described below can be combined as appropriate, and when there are multiple embodiments, each embodiment can be combined.

[Embodiment 1]
The heat exchanger 1 according to Embodiment 1 is a heat exchanger in which a structure in which inner fins are provided between a pair of plates is laminated, and is called a so-called plate heat exchanger. In the heat exchanger 1, heat is exchanged between a high-temperature side fluid and a low-temperature side fluid that flow inside. The fluid flowing through the heat exchanger 1 may be liquid or gas, and is not particularly limited.

FIG. 1 is a perspective view schematically showing the heat exchanger according to Embodiment 1. FIG. 2 is a perspective view showing offset fins of the heat exchanger according to Embodiment 1. FIG. FIG. 3 is a two-sided view of the offset fin. FIG. 4 is a cross-sectional view of an offset fin. FIG. 5 is an explanatory diagram regarding the flow of fluid.

(Heat exchanger)
The heat exchanger 1 includes a plurality of plates 10 and inner fins 12 provided between the plates 10 . The plate 10 is formed in a plate shape. The plurality of plates 10 are arranged at predetermined intervals in the direction in which their plate surfaces face each other, that is, in the thickness direction. In the plate 10, the high-temperature side fluid flows on one side in the thickness direction, and the low-temperature side fluid flows on the other side in the thickness direction. A metal material with high heat transfer performance is used for the plate 10 .

The inner fins 12 are provided between a pair of adjacent plates 10 and joined to the plates 10 by brazing. That is, the inner fin 12 is joined to the plate 10 on one side at one side in the thickness direction, and joined to the plate on the other side at the other side in the thickness direction. The inner fins 12 function as strength members that support the space between the pair of plates 10 . Further, the inner fins 12 are provided with flow paths through which fluid flows. Therefore, the fluid flows between the pair of plates 10 facing each other, that is, inside the inner fins 12 .

The plurality of plates 10 and inner fins 12 are alternately arranged and joined in the thickness direction. Therefore, the flow paths formed by the inner fins 12 are partitioned by the plate 10 so that a plurality of flow paths are formed side by side in the thickness direction. The plurality of flow paths arranged in the thickness direction circulate the high-temperature side fluid and the low-temperature side fluid so that the flow path for the high-temperature side fluid and the flow path for the low-temperature side fluid alternate. Moreover, the flow path is formed so that the fluid flows in one direction in a plane perpendicular to the thickness direction. The direction of flow of the high-temperature side fluid and the direction of flow of the low-temperature side fluid are opposite to each other.

In such a heat exchanger 1, when the high-temperature side fluid and the low-temperature side fluid flow, the high-temperature side fluid flows in a predetermined flow direction, and the low-temperature side fluid flows in a direction opposite to the flow direction of the high-temperature side fluid. flow in the direction The high-temperature side fluid and the low-temperature side fluid are heat-exchanged via the plate 10 and the inner fins 12 .

Next, the inner fins 12 will be described with reference to FIGS. 2 to 4. FIG. As shown in FIGS. 2 to 4, the inner fin 12 has a plurality of offset fins 15. As shown in FIG. A plurality of offset fins 15 are arranged side by side along the flow direction of the fluid. Also, the plurality of offset fins 15 are provided in a plane orthogonal to the thickness direction, offset from each other in the width direction orthogonal to the flow direction.

The offset fins 15 are provided across the width direction. The offset fins 15 have apexes 15a that protrude upstream in the flow direction, and troughs 15b that are recessed downstream in the flow direction. It has a wavy shape. The offset fins 15 on one side adjacent in the flow direction and the offset fins 15 on the other side adjacent in the flow direction are arranged line-symmetrically with respect to the width direction as an axis of symmetry, and are mutually offset in the width direction. are placed as follows. In addition, the offset fin 15 has an angle θa between the top portion 15a and the valley portion 15b in a range of 60 degrees to 160 degrees when viewed from above in a height direction orthogonal to the flow direction and the width direction.

Here, as shown in FIG. 3, the offset fins 15 are arranged in four rows in the flow direction as one set. The first row of offset fins 15 on the upstream side in the flow direction and the third row of offset fins 15 on the downstream side are at the same position in the width direction. The offset fins 15 in the second row are offset to one side in the width direction (right side in FIGS. 3 and 4) with respect to the offset fins 15 in the first and third rows. The offset fins 15 in the fourth row are offset from the offset fins 15 in the first and third rows to the other side in the width direction (left side in FIGS. 3 and 4).

Specifically, as shown in FIG. 4, the distance between the tops in the width direction is set to 1 unit. In this case, the offset fins 15 in the second row are offset from the offset fins 15 in the first and third rows to one side in the width direction by ½ unit. Also, the offset fins 15 in the fourth row are offset from the offset fins 15 in the first and third rows to the other side in the width direction by ½ unit. In the first embodiment, the offset fins 15 in the second and fourth rows are offset by 1/2 units, but if the shape of the offset fins 15 does not restrict the offset fins 15, the offset fins 15 may be offset by 1/4 to 1/2 units. is preferably offset within the range of .

Next, the offset fins 15 will be explained. The offset fin 15 has a plate joint portion 21, a fin portion 22, and a blocking portion 23, and these portions are integrated.

The plate joint portion 21 is a portion that is joined to the plate 10 . The plate joint portion 21 includes a plate joint portion 21 a joined to one side of the pair of plates 10 and a plate joint portion 21 b joined to the other side of the pair of plates 10 . The plate joint portion 21 is formed in a parallelogram plate shape or a V-shaped plate shape obtained by symmetrically developing a parallelogram in the width direction. The plate joint portion 21 forms part of the top portion 15 a and the valley portion 15 b of the offset fin 15 . In addition, the plate joint portion 21 has a surface facing the plate 10 joined to the plate 10 , so that an end portion in the flow direction exposed on the inner channel side is formed as a stepped portion 25 .

The fin portion 22 is provided over the thickness direction. The fin portion 22 is connected to the widthwise end portion of the plate joint portion 21 . The fin portion 22 is formed in a plate shape.

The blocking portion 23 is provided at the plate joint portion 21 . The inhibition portion 23 is a portion that inhibits the formation of a thermal boundary layer generated in the fluid flowing along the inner side of the plate joint portion 21 . Specifically, the obstruction portion 23 is a receiving slope 38 that receives the fluid in the stepped portion 25 and is oblique with respect to the flow direction. Since the receiving slope 38 is oblique with respect to the flow direction of the fluid, the fluid flowing along the receiving slope 38 becomes a swirling flow that circulates in the circumferential direction about the flow direction.

The flow of fluid flowing through the inner fins 12 of Embodiment 1 will be described with reference to FIG. FIG. 5 is a cross-section cut along a plane orthogonal to the flow direction, the upper side of the drawing is the upstream side in the flow direction, and the lower side of the drawing is the downstream side in the flow direction. The fluid flowing along the receiving slope 38 generates a flow R1 from the top portion 15a to the valley portion 15b in the width direction as it goes from the upstream side to the downstream side in the flow direction. When the flow R1 directed from the top portion 15a to the valley portion 15b is applied to the fluid, the fluid becomes a swirling flow R2 swirling in the flow direction from the top portion 15a to the valley portion 15b. The fluid that becomes the swirling flow R2 has an increased flow velocity inside the plate joint portion 21, and thus inhibits formation of a temperature boundary layer that occurs inside the plate joint portion 21. FIG.

[Embodiment 2]
Next, Embodiment 2 will be described with reference to FIGS. 6 to 8. FIG. In order to avoid redundant description, in the second embodiment, portions different from those in the first embodiment will be described, and portions having the same configuration as in the first embodiment will be described with the same reference numerals. FIG. 6 is a perspective view showing offset fins of the heat exchanger according to Embodiment 2. FIG. FIG. 7 is a perspective view showing projections of offset fins. FIG. 8 is a two-sided view of the offset fin.

(Heat exchanger)
A heat exchanger 50 of the second embodiment differs from the offset fins 15 of the first embodiment in the plurality of offset fins 51 in the inner fins 12 .

A plurality of offset fins 51 are arranged side by side along the flow direction of the fluid. In addition, the plurality of offset fins 51 are offset in the width direction perpendicular to the flow direction in the plane perpendicular to the thickness direction.

The offset fins 51 are provided across the width direction. In other words, the offset fin 15 is a long member whose longitudinal direction is the width direction. As shown in FIGS. 6 and 8, the offset fin 51 has a plate joint portion 61, a fin portion 62, and an obstruction portion 63, and these portions are integrated.

The plate joint portion 61 is a portion that is joined to the plate 10 . Similar to the plate joint portion 21 of the first embodiment, the plate joint portion 61 includes a plate joint portion 61a joined to one side of the pair of plates 10 and a plate joint portion 61b joined to the other side of the pair of plates 10. and includes The plate joint portion 61 is formed in a square plate shape. In addition, the plate joint portion 61 has a surface facing the plate 10 joined to the plate 10 , so that an end portion in the flow direction exposed on the inner channel side is formed as the stepped portion 25 .

The fin portion 62 is provided over the thickness direction. The fin portion 62 is connected to the widthwise end portion of the plate joint portion 61 . The fin portion 62 is formed in a plate shape.

The blocking portion 63 is provided at the plate joint portion 61 . As in the first embodiment, the inhibition portion 63 is a portion that inhibits the formation of a temperature boundary layer generated in the fluid that flows along the inner side of the plate joint portion 61 . Specifically, the blocking portion 63 is a protrusion 65 that protrudes inward from the plate joint portion 61 . When the plate joints 61 are continuous in the offset fins 51 adjacent in the flow direction, the projecting portion 65 is provided at the plate joint 61 on the upstream side in the flow direction.

The protrusion 65 is formed in a rectangular shape elongated in the flow direction when viewed from the height direction orthogonal to the flow direction and the width direction. Moreover, the protrusion 65 is formed in a triangular shape that is convex in the protrusion direction when viewed from the front in the flow direction. In the second embodiment, the protrusion 65 has a rectangular shape in plan view and a triangular shape in front view, but the shape is not particularly limited to this. The protrusion 65 may have a polygonal shape or an annular shape such as a circle or an ellipse in a plan view, and may have a polygonal shape, a semicircular shape, or a semicircular shape in a front view. An arc shape such as an ellipse may be used.

The projecting portion 65 has a first guide slope 65a that slopes from the upstream side to the downstream side in the flow direction, and a second guide slope 65b that slopes from one side to the other side in the width direction. ing. The first guide slope 65a includes an upstream guide slope 65a and a downstream guide slope 65a. Assuming that the angle formed by the first guide slope 65a and the flow direction is a first inclination angle θ1, the first inclination angle θ1 is in the range of 10 degrees to 60 degrees. Here, the first inclination angle θ1 on the downstream side may be the same as the first inclination angle θ1 on the upstream side, or may be larger than the first inclination angle θ1 on the upstream side with an upper limit of 90 degrees. good too. The second guide slope 65b includes a guide slope 65b on one side in the width direction and a guide slope 65b on the other side in the width direction. Assuming that the angle formed by the second guide slope 65b and the width direction is a second inclination angle θ2, the inclination angles θ2 of the second guide slopes 65b on both sides in the width direction are the same.

Further, as shown in FIG. 8, the protrusions 65 are provided at predetermined positions in the flow direction and the width direction. Specifically, the projecting portion 65 is arranged with a distance L1 equal to or greater than the thickness of the fin portion 62 from the end portion of the plate joint portion 61 in the flow direction. In addition, the projecting portion 65 is spaced apart from the fin portion 62 by a distance L2 equal to or greater than the thickness of the fin portion 62 in the width direction.

In the heat exchanger 50 of the second embodiment, part of the fluid that flows inside the inner fins 12 in the flow direction crosses over the stepped portion 25, reaches the projecting portion 65, and flows along the first guide slope 65a. . At the plate joint portion 61, the flow velocity of the fluid flowing along the first guide slope 65a of the protrusion 65 and the fluid flowing along the plate joint portion 61 without the protrusion 65 are different. Therefore, a pressure gradient is generated between the fluids, and the pressure gradient generates a cross-sectional secondary flow whose cross section is a plane perpendicular to the flow direction. This cross-sectional secondary flow increases the flow velocity of the fluid inside the plate joint portion 21 , thereby inhibiting the formation of a temperature boundary layer that occurs inside the plate joint portion 21 .

In the second embodiment, the protrusions 65 have a rectangular shape elongated in the flow direction in plan view, but may be arranged as indicated by the dotted lines in FIG. That is, the projecting portion 65 may have a rectangular shape elongated in a direction inclined with respect to the flow direction in plan view. Specifically, if the angle formed by the length direction of the protrusion 65 and the flow direction is defined as an inclination angle θ3, the inclination angle θ3 ranges from 0 degrees to 45 degrees.

[Embodiment 3]
Next, Embodiment 3 will be described with reference to FIGS. 9 to 12. FIG. Note that in the third embodiment, portions different from those in the first and second embodiments will be described in order to avoid redundant description, and portions having the same configurations as in the first and second embodiments will be described with the same reference numerals. 9 is a perspective view showing offset fins of a heat exchanger according to Embodiment 3. FIG. FIG. 10 is a plan view of the offset fin. FIG. 11 is a cross-sectional view of an offset fin. FIG. 12 is an explanatory diagram regarding the flow of fluid.

(Heat exchanger)
A heat exchanger 70 of the third embodiment differs from the offset

fins

15 and 51 of the first and second embodiments in the plurality of offset fins 71 in the inner fins 12 .

A plurality of offset fins 71 are obtained by replacing the blocking portions 63 of the second embodiment with blocking portions 83 . Therefore, the blocking portion 83 of the offset fin 71 will be described, and the plate joint portion 81 and the fin portion 82 of the offset fin 71, which are other portions, are the same as the plate joint portion 61 and the fin portion 62 of the second embodiment. Therefore, the description is omitted.

The blocking portion 83 is provided at the plate joint portion 81 . As in the first embodiment, the inhibition portion 83 is a portion that inhibits the formation of a thermal boundary layer generated in the fluid that flows along the inner side of the plate joint portion 81 . Specifically, the obstruction portion 83 is a hole 85 that enters from the plate joint portion 81 toward the plate 10 side. When the plate joints 81 are continuous in the offset fins 71 adjacent in the flow direction, the holes 85 are provided in the plate joints 81 on the downstream side in the flow direction. The hole 85 is a through hole formed through the plate joint portion 81 . Although the hole 85 is a through hole in the third embodiment, it may be a bottomed hole. At least one or more holes 85 are provided in the inner fin 12 in the machine direction and the width direction.

The hole 85 is formed in a square shape when viewed from the height direction orthogonal to the flow direction and the width direction. In addition, in the third embodiment, the hole 85 has a square shape in plan view, but is not particularly limited to this shape. The hole 85 may have a polygonal shape or an annular shape such as a circular or elliptical shape in plan view. The hole 85 has a longest length L5 that is two to eight times the thickness of the fin portion 82 in plan view.

Also, as shown in FIG. 10, the holes 85 are provided at predetermined positions in the flow direction and the width direction. Specifically, the hole 85 is arranged with a distance L3 that is equal to or greater than the thickness of the fin portion 82 from the end portion of the plate joint portion 81 in the flow direction. Moreover, the hole 85 is spaced apart from the fin portion 62 by a distance L4 equal to or greater than the thickness of the fin portion 62 in the width direction.

Next, the plate joint portion 81 will be described with reference to FIGS. 11 and 12. FIG. The plate joint portion 81 has a downstream slope 81a formed at the downstream end in the flow direction. The downstream slope 81a is a portion on the downstream side of the plate joint portion 81 where the other plate joint portion 81 is not adjacent to the downstream side in the flow direction, that is, a portion where the stepped portion 88 is formed (see conventional in FIG. 12). formed in Assuming that the angle formed by the downstream side slope 81a and the flow direction is the downstream side inclination angle θ4, the downstream side inclination angle θ4 is in the range of 7 degrees to 45 degrees.

As shown in FIG. 12 , conventionally, when the plate joint portion 81 is not provided with the downstream slope 81 a, the downstream end portion of the plate joint portion 81 becomes the stepped portion 88 . Therefore, the fluid flowing through the inner surface of the plate joint portion 81 passes through the stepped portion 88 to form a separation region due to the separation flow R3. On the other hand, in the third embodiment, when the plate joint portion 81 is provided with the downstream slope 81a, the fluid flowing through the inner surface of the plate joint portion 81 flows along the downstream slope 81a, thereby forming the separation flow R3. Suppressed.

In the heat exchanger 70 of Embodiment 3, part of the fluid that flows inside the inner fins 12 in the flow direction crosses over the stepped portion 25 and reaches the hole 85 . The fluid flowing along the plate joint 81 is separated at the hole 85 , thereby initializing the formation of the thermal boundary layer generated inside the plate joint 21 .

As described above, the

heat exchangers

1, 50, and 70 described in this embodiment are understood as follows, for example.

A heat exchanger 1 according to a first aspect includes a pair of plates 10 facing each other, and inner fins 12 provided between the pair of plates 10 and through which a fluid flows. , a plurality of offset fins 15 arranged side by side along the flow direction of the fluid and offset from each other in the width direction orthogonal to the flow direction, the offset fins 15 being arranged on the plate 10 a plate joint portion 21 having a stepped portion 25 formed in the flow direction; a fin portion 22 connected to the plate joint portion 21 and provided along the facing direction of the pair of plates 10; a receiving slope 38 provided at the plate joint 21 and oblique to the flow direction for receiving the fluid of the stepped portion 25 .

According to this configuration, the swirling flow R2 can be imparted to the fluid by the receiving slope 38. Therefore, since the flow velocity increases inside the plate joint portion 21 due to the swirl flow R2, the formation of the temperature boundary layer generated inside the plate joint portion 21 can be inhibited appropriately. Therefore, it is possible to reduce the thickness of the temperature boundary layer and suppress deterioration of the heat transfer performance via the plate 10 , thereby suppressing deterioration of the heat exchange performance of the heat exchanger 1 .

As a second aspect, the offset fins 15 have a top portion 15a on the upstream side in the flow direction and a valley portion 15b on the downstream side in the flow direction, and the top portion 15a and the valley portion 15b The offset fins 15 on one side adjacent in the flow direction and the offset fins 15 on the other side adjacent in the flow direction are arranged alternately along the width direction. They are arranged axisymmetrically with the direction as an axis of symmetry, and are arranged with positions offset from each other in the width direction.

According to this configuration, the offset fins 15 can be arranged line-symmetrically and offset, so that only one type of the offset fins 15 can be used for the inner fins 12, which reduces the manufacturing cost. reduction can be achieved.

As a third aspect, the offset fins 15 are arranged in four rows in the flow direction as one set, and the offset fins 15 in the first row and the offset fins 15 in the third row are arranged in the width direction. The offset fins 15 of the second row are offset to one side in the width direction with respect to the offset fins 15 of the first and third rows, and the offset fins 15 of the fourth row are positioned at the same position. is offset to the other side in the width direction with respect to the offset fins 15 of the first and third rows.

According to this configuration, the offset fins 15 can be placed in a suitable arrangement that inhibits the formation of the temperature boundary layer. In addition, by arranging one set of offset fins 15 in the flow direction, the inner fins 12 can be easily configured.

A heat exchanger 50 according to a fourth aspect includes a pair of plates 10 facing each other, and inner fins 12 provided between the pair of plates 10 and through which a fluid flows. , a plurality of offset fins 51 arranged side by side along the flow direction of the fluid and offset from each other in the width direction orthogonal to the flow direction, the offset fins 51 being arranged on the plate 10 a plate joint portion 61 joined to the plate joint portion 61; a fin portion 62 connected to the plate joint portion 61 and provided along the facing direction of the pair of plates 10; and a projection 65 projecting inwardly from 61 .

According to this configuration, the protrusion 65 can impart a cross-sectional secondary flow to the fluid. For this reason, since the cross-sectional secondary flow increases the flow velocity on the inner side of the plate joint portion 21 , the formation of the temperature boundary layer generated on the inner side of the plate joint portion 21 can be inhibited appropriately. Therefore, it is possible to reduce the thickness of the temperature boundary layer and suppress deterioration of the heat transfer performance via the plate 10 , thereby suppressing deterioration of the heat exchange performance of the heat exchanger 50 .

As a fifth aspect, when the plate joint portions 61 are continuous in the offset fins 51 adjacent in the flow direction, the projecting portion 65 is provided at the plate joint portion 61 on the upstream side in the flow direction.

According to this configuration, since the projecting portion 65 can provide a cross-sectional secondary flow on the upstream side in the flow direction, it is possible to suitably inhibit the formation of a temperature boundary layer on the downstream side.

As a sixth aspect, the protrusion 65 is composed of a guide slope 65a that slopes from the upstream side to the downstream side in the flow direction and a guide slope 65b that slopes from one side to the other side in the width direction. At least one of the guide slopes 65a and 65b is provided.

According to this configuration, the cross-sectional secondary flow can be easily imparted to the fluid by circulating the fluid along the guide slopes 65a and 65b.

As a seventh aspect, the protrusion 65 has a shape elongated in a direction inclined with respect to the flow direction.

According to this configuration, the cross-sectional secondary flow can be easily imparted to the fluid by circulating the fluid along the length direction of the protrusion 65 .

As an eighth aspect, the protrusion 65 is arranged with a distance L1 equal to or greater than the thickness of the fin portion 62 from the end portion of the plate joint portion 61 in the flow direction, and in the width direction , are spaced apart from the fin portion 62 by a distance L2 equal to or greater than the thickness of the fin portion 62 .

According to this configuration, the arrangement of the protrusions 65 can be a suitable arrangement for imparting a cross-sectional secondary flow to the fluid.

A heat exchanger 70 according to a ninth aspect includes a pair of plates 10 facing each other, and inner fins 12 provided between the pair of plates 10 and through which a fluid flows. , a plurality of offset fins 71 arranged side by side along the flow direction of the fluid and offset from each other in the width direction orthogonal to the flow direction, the offset fins 71 being arranged on the plate 10 a plate joint portion 81 joined to the plate joint portion 81; a fin portion 82 connected to the plate joint portion 81 and provided along the facing direction of the pair of plates 10; and a hole 85 recessed from 81 toward the plate 10 side.

According to this configuration, the holes 85 can separate the fluid flow. Therefore, by separating the flow of the fluid, the formation of the thermal boundary layer can be initialized, so that the formation of the thermal boundary layer can be favorably inhibited. Therefore, the thickness of the thermal boundary layer can be reduced to suppress deterioration in heat transfer performance via the plate 10, thereby suppressing deterioration in the heat exchange performance of the heat exchanger 70. FIG.

As a tenth aspect, when the plate joint portions 81 are continuous in the offset fins 71 adjacent in the flow direction, the holes 85 are provided in the plate joint portions 81 on the downstream side in the flow direction.

According to this configuration, it is possible to initialize the formation of the temperature boundary layer on the downstream side where the temperature boundary layer becomes thicker due to the holes 85, so it is possible to suitably inhibit the formation of the temperature boundary layer on the downstream side.

As an eleventh aspect, the hole 85 has a maximum length in the plane of the plate 10 that is two to eight times the thickness of the fin portion 82 .

According to this configuration, the size of the hole 85 can be set to a suitable size for initializing the formation of the temperature boundary layer.

As a twelfth aspect, the hole 85 is arranged with a distance L3 equal to or greater than the thickness of the fin portion 82 from the end portion of the plate joint portion 81 in the flow direction, and in the width direction, With respect to the fin portion 82, a distance L4 equal to or greater than the thickness of the fin portion 82 is provided.

According to this configuration, the arrangement of the holes 85 can be a suitable arrangement for initializing the formation of the temperature boundary layer.

As a thirteenth aspect, the plate joint portion 81 is formed at the downstream end in the flow direction, and has a downstream inclined surface 81a inclined toward the plate 10 toward the downstream side in the flow direction. .

According to this configuration, the formation of the separation flow R3 is suppressed by the fluid flowing along the downstream slope 81a. Therefore, the heat transfer area of the fluid on the downstream side of the plate joint portion 81 can be increased to the extent that the formation of the separated flow R3 is suppressed, and the heat transfer performance can be improved. Moreover, pressure loss can be reduced by suppressing the formation of the separation flow R3.

Reference Signs List 1 heat exchanger 10 plate 12 inner fin 15 offset fin 21 plate joint portion 22 fin portion 23 blocking portion 25 stepped portion 38 receiving slope 50 heat exchanger (second embodiment)
51 offset fin 61 plate joint portion 62 fin portion 63 inhibition portion 65 projection portion 70 heat exchanger (third embodiment)
71 offset fin 81 plate junction 82 fin portion 83 blocking portion 85 hole 88 stepped portion

Claims

a pair of plates facing each other;
an inner fin provided between the pair of plates and through which a fluid flows;
The inner fins are
a plurality of offset fins arranged side by side along the flow direction of the fluid and offset from each other in the width direction orthogonal to the flow direction;
The offset fins are
a plate joint portion joined to the plate and having a stepped portion formed in the flow direction;
a fin portion connected to the plate joint portion and provided along the facing direction of the pair of plates;
a receiving slanted surface of the stepped portion, which is provided at the plate joint portion and is oblique with respect to the flow direction, for receiving the fluid.
The offset fin has a crest at a portion on the upstream side in the flow direction and a trough at a portion on the downstream side in the flow direction, and the crest and the trough are provided alternately along the width direction. It has the shape of
The offset fins on one side adjacent to the flow direction and the offset fins on the other side adjacent to the flow direction are arranged line-symmetrically with respect to the width direction as an axis of symmetry, and are mutually arranged in the width direction. 2. A heat exchanger according to claim 1, arranged in an offset position.
The offset fins are arranged in four rows in the flow direction as one set,
The offset fins in the first row and the offset fins in the third row are at the same position in the width direction,
The offset fins in the second row are offset to one side in the width direction with respect to the offset fins in the first row and the third row,
3. The heat exchanger according to claim 1, wherein the offset fins in the fourth row are offset to the other side in the width direction with respect to the offset fins in the first row and the third row.
a pair of plates facing each other;
an inner fin provided between the pair of plates and through which a fluid flows;
The inner fins are
a plurality of offset fins arranged side by side along the flow direction of the fluid and offset from each other in the width direction orthogonal to the flow direction;
The offset fins are
a plate joint joined to the plate;
a fin portion connected to the plate joint portion and provided along the facing direction of the pair of plates;
a projection provided at the plate joint and projecting inwardly from the plate joint.
When the plate joint portions are continuous in the offset fins adjacent to each other in the flow direction,
5. The heat exchanger according to claim 4, wherein the protrusion is provided at the plate joint on the upstream side in the flow direction.
The projecting portion has at least one of a guide slope inclined from the upstream side to the downstream side in the flow direction and a guide slope sloped from one side to the other side in the width direction. 6. A heat exchanger according to claim 4 or 5, comprising:
The heat exchanger according to claim 4 or 5, wherein the projection has a shape elongated in a direction inclined with respect to the flow direction.
The protrusion is
arranged at a distance equal to or greater than the thickness of the fin portion with respect to the end portion of the plate joint portion in the flow direction;
The heat exchanger according to any one of claims 4 to 7, wherein the heat exchanger is arranged with a distance equal to or greater than the thickness of the fin portion with respect to the fin portion in the width direction.
a pair of plates facing each other;
an inner fin provided between the pair of plates and through which a fluid flows;
The inner fins are
a plurality of offset fins arranged side by side along the flow direction of the fluid and offset from each other in the width direction orthogonal to the flow direction;
The offset fins are
a plate joint joined to the plate;
a fin portion connected to the plate joint portion and provided along the facing direction of the pair of plates;
A heat exchanger comprising: a hole provided in the plate joint portion and recessed from the plate joint portion toward the plate side.
When the plate joint portions are continuous in the offset fins adjacent to each other in the flow direction,
10. The heat exchanger according to claim 9, wherein the hole is provided at the plate joint on the downstream side in the flow direction.
The heat exchanger according to claim 9 or 10, wherein the hole has a longest length in the plane of the plate that is two to eight times the thickness of the fin portion.
The holes are
arranged at a distance equal to or greater than the thickness of the fin portion with respect to the end portion of the plate joint portion in the flow direction;
The heat exchanger according to any one of claims 9 to 11, wherein the heat exchanger is arranged with a distance equal to or greater than the thickness of the fin portion with respect to the fin portion in the width direction.
13. Any one of claims 1 to 12, wherein the plate joint portion is formed at an end portion on the downstream side in the flow direction, and has a downstream slope that slopes toward the plate side toward the downstream side in the flow direction. A heat exchanger according to any one of the preceding paragraphs.