CN107024132B

CN107024132B - Fin for heat exchanger and heat exchanger

Info

Publication number: CN107024132B
Application number: CN201710044254.7A
Authority: CN
Inventors: 余园满; 谢健; 胡义红; 熊永家; 李理; 尤勇利; 王岩喜; 金岳
Original assignee: Zhejiang Yinlun Machinery Co Ltd
Current assignee: Zhejiang Yinlun Machinery Co Ltd
Priority date: 2017-01-19
Filing date: 2017-01-19
Publication date: 2023-03-21
Anticipated expiration: 2037-01-19
Also published as: CN107024132A

Abstract

The invention belongs to the technical field of engineering machinery, and particularly relates to a fin for a heat exchanger and the heat exchanger, which can be used in places with more dust, and has the advantages of good anti-blocking performance, low wind resistance and high heat exchange efficiency. The heat transfer surface is provided with a plurality of V-shaped concave-convex parts arranged along the long axis, the long axis is the central line along the length direction of the heat transfer surface, each V-shaped concave-convex part comprises convex strips and concave strips, the convex strips and the concave strips are alternately arranged, convex peaks and concave peaks of the V-shaped concave-convex parts are mutually staggered along the long axis, and the staggered distance is L. The V-shaped fin has no large-amplitude concave-convex part, does not cause obvious detention areas in the concave part, and has lower wind resistance under the same wind speed; in addition, the radiating surface of the invention is provided with V-shaped concave-convex which are staggered with each other, secondary flow on the flow section is strengthened, the temperature boundary layer is further destroyed, and the heat exchange performance is strengthened.

Description

Fin for heat exchanger and heat exchanger

The technical field is as follows:

the invention belongs to the technical field of engineering machinery, and particularly relates to a fin for a heat exchanger and a heat exchanger, which can be used in places with more dust, and have the advantages of good anti-blocking property, low wind resistance and high heat exchange efficiency.

Background art:

engineering machine tool belongs to non-road machine, and its operational environment is poor, and the dust is many, and easy air intake department and the inside surface attachment dust of fin, long-time accumulation back can cause the jam, greatly reduced heat transfer performance, so the fin that the stifled nature of a section of preventing is good urgently needed. Meanwhile, along with the improvement of emission standards and noise standards, the electronic fan is applied to engineering machinery, the noise is low, the air volume of each radiator can be controlled in a partition mode through a plurality of fans, and noise reduction, energy conservation and emission reduction are achieved. However, the electronic fan is limited by the performance of the motor, the static pressure of the electronic fan is low, and due to the space limitation, the electronic fan can be arranged only in parallel (the static pressure is unchanged after parallel connection, and only the air volume can be increased), but not in series. Therefore, the electronic fan puts higher requirements on the heat exchanger, namely, a fin with low wind resistance and high heat exchange efficiency is needed.

Most of the fin technologies of the existing engineering machinery are wave-shaped fins, and as shown in fig. 1, good anti-blocking performance is guaranteed by adjusting the spacing of the fins; the wind resistance and the heat exchange efficiency are balanced by adjusting the ratio of the wave length to the wave amplitude of the wave shape.

The prior art is improved as follows: 1. japanese hitachi demonstrated that the wavy fin causes the ventilation resistance to increase to a degree higher than the rate of increase in the heat exchange performance due to the retention of air in the recess; further, a fin with V-shaped protrusions and recesses for an air conditioner is proposed (patent document 1), which has a lower wind resistance and a higher heat exchange efficiency, and which can solve the problem of clogging due to condensed water. 2. In the fin with the V-shaped irregularities, university of tokyo in japan summarizes parameterized formulas for optimum performance through parameterized computational analysis, and proposes a fin with W-shaped folded irregularities (patent document 2). 3. Rad company improved a W-shaped folded uneven fin of the university of tokyo, japan, and proposed an asymmetric V-shaped uneven fin with unequal tilt angles (patent document 3), and demonstrated that this structure has a better dust removal effect.

Patent document 1: japanese Kokai publication Hei-1-219497;

patent document 2: chinese invention patent CN200880003112.5;

patent document 3: chinese invention patent CN201110349342.0.

However, the above improved techniques still have the following drawbacks:

as shown in fig. 1, in the wave-shaped fin, air forms a stagnation area in the concave portion, and as the wind speed increases, the stagnation effect becomes more and more obvious, which causes the wind resistance to rise remarkably; and the wavy fins have stable temperature boundary layers on the cross section in the flowing direction, so that the heat exchange performance is deviated.

As shown in fig. 2, the streamline schematic diagram of the wave-shaped fin when the reynolds number Re is respectively 50, 100, 400, the air at the front end 10 of the convex part is squeezed, the boundary layer becomes thin, and the heat exchange efficiency is improved, which is the source of the wave-shaped fin for enhancing the heat exchange. However, after passing through the front end 10 of the convex part, the air forms a stagnation region 20 in the concave part, a significant vortex is generated, the thickness of a boundary layer of the stagnation region is significantly higher than that of other regions, the heat exchange effect is the worst, the stagnation effect becomes more and more significant with the increase of the wind speed (i.e. the reynolds number Re), and the wind resistance is caused to be significantly increased at a degree higher than the increase rate of the heat exchange performance.

The velocity vector diagram of the wave type fin shown in fig. 3. The wave-shaped fin has a relatively stable temperature boundary layer on the flow section, which causes deviation of heat exchange performance.

In addition, the temperature cloud of the wave-shaped fin shown in fig. 4 has a distinct temperature boundary layer, and a large long low-temperature region 30 exists in the center of the temperature cloud, which is the largest. And fig. 5 is a temperature cloud chart of a conventional V-shaped fin, and a part of a temperature boundary layer is damaged due to secondary flow generated by V-shaped concave-convex, so that the range of the low-temperature region 30 is reduced, and only small regions at two ends are provided, so that the heat exchange performance is enhanced compared with a wave-shaped fin. Wherein, a schematic view of a conventional V-shaped fin is shown in FIG. 6.

The invention content is as follows:

aiming at the technical defects in the prior art, the invention provides the fin for the heat exchanger, which is particularly suitable for the field of engineering machinery with more dust and has the advantages of good anti-blocking performance, low wind resistance and high heat exchange efficiency.

The technical scheme adopted by the invention is as follows:

a fin for a heat exchanger is provided with a plurality of V-shaped concave-convex parts arranged along a long shaft on a heat transfer surface, the long shaft is a central line along the length direction of the heat transfer surface, each V-shaped concave-convex part comprises convex strips and concave strips, the convex strips and the concave strips are alternately arranged, convex peaks and concave peaks of the V-shaped concave-convex parts are mutually staggered along the long shaft, and the staggered distance is L.

In the fin for a heat exchanger described above, first inclined planes and second inclined planes are formed between the convex strips and the concave strips of each V-shaped concavo-convex pattern, the first inclined planes have a small inclination angle and a large width, and the second inclined planes have a large inclination angle and a small width.

In the above-described fin for a heat exchanger, the first inclined surfaces and the second inclined surfaces are alternately arranged in the long axis direction.

In the above-described fin for a heat exchanger, the first inclined surfaces and the second inclined surfaces are alternately arranged in a direction of a short axis, which is a center line in a width direction of the heat transfer surface.

In the above fin for a heat exchanger, the bent portion of the heat transfer surface is provided with a chamfer for improving manufacturability and enhancing dust removal.

In the above-mentioned fin for a heat exchanger, each convex strip of the V-shaped concave-convex is V-shaped and symmetrically arranged, and the concave strips are V-shaped and symmetrically arranged.

In the above-described fin for a heat exchanger, the offset distance: l is more than or equal to 0.4mm and less than or equal to 0.8mm.

In the above-described fin for a heat exchanger, the convex peaks and the concave peaks are equidistant from the major axis.

Another object of the present invention is to provide a heat exchanger comprising a fin for a heat exchanger as described above.

Compared with the prior art, the invention has the outstanding advantages that:

1. the V-shaped fin has no large-amplitude concave-convex part, does not cause obvious detention areas in the concave part, and has lower wind resistance under the same wind speed; in addition, the radiating surface of the invention is provided with V-shaped concave-convex which are staggered with each other, secondary flow on the flow section is strengthened, the temperature boundary layer is further destroyed, and the heat exchange performance is strengthened.

2. In the invention, the vertexes of the V-shaped concave-convex are staggered around the long axis, and finally, a first inclined plane and a second inclined plane which are alternately arranged are formed between the convex strip and the concave strip. The first inclined plane has a small inclination angle and a large width, and the second inclined plane has a large inclination angle and a small width. The first inclined plane and the second inclined plane are alternately arranged along the long axis direction, and the flow (secondary flow) of air in the X axis direction is enhanced due to different inclination angles and widths of the two inclined planes; meanwhile, the first inclined planes and the second inclined planes are alternately arranged along the short axis direction, and the flow (secondary flow) of air in the Y-axis direction is enhanced due to the difference of the inclination angle and the width of the two inclined planes. Due to the combined action of the secondary flows in the X-axis direction and the Y-axis direction, a plurality of vortexes are formed, the forced convection between the middle and the side surface is enhanced, a temperature boundary layer and a speed boundary layer are further damaged, and the heat exchange performance is enhanced.

3. The invention is provided with a chamfer at the bending position. The chamfer angle can greatly improve the manufacturability on one hand, because the machinability of the right-angle structure is poor and the demoulding is influenced, and the inclined chamfer angle can avoid the defects; on the other hand, a small flat area is formed at the chamfer, the ventilation resistance is low, the air flow rate is high, the dust can be taken away, and the dust removal effect is enhanced.

Description of the drawings:

fig. 1 is a perspective view of a wave-shaped fin of the background art.

Fig. 2 is a schematic view of temperature flow lines of a related art wave-type fin.

Fig. 3 is a velocity vector diagram of a background art undulating fin.

Fig. 4 is a temperature cloud of a prior art wave fin.

FIG. 5 is a temperature cloud of a conventional V-fin of the background art.

Fig. 6 is a perspective view of a V-shaped fin of the background art.

Fig. 7 is a front view of the present invention.

Fig. 8 is a cross-sectional view of the present invention.

Fig. 9 is a perspective view of the present invention.

FIG. 10 is a vector diagram of the velocity of the V-shaped fins of the present invention.

FIG. 11 is a temperature cloud of the V-shaped fins of the present invention.

Fig. 12 isbase:Sub>A sectional viewbase:Sub>A-base:Sub>A of fig. 1, and reynolds number Re =400.

Fig. 13 is a B-B sectional view of fig. 6, and the reynolds number Re =400.

FIG. 14 is a schematic view of the V-shaped fin of the present invention assembled with a heat pipe to form a heat dissipating core.

In the figure, 10, the projection tip; 20. a stagnant zone; 30. a low temperature region; 1. a heat transfer surface; 2. a long axis; 3a, convex strips; 3b, concave strips; 4a, convex vertex; 4b, concave vertex points; 5a, a first inclined plane; 5b, a second inclined plane; 6. a minor axis; 7. chamfering; 8. a radiating pipe; 9. a low temperature region.

The specific implementation mode is as follows:

the present invention will be described in further detail with reference to the accompanying drawings, wherein the V-shaped protrusions are enlarged for clarity and convenience of illustration, so that the drawings are only for clarity of understanding and are not intended to limit the present invention.

As shown in FIGS. 7, 8 and 9, the fin for a heat exchanger of the present invention has a plurality of V-shaped convexo-concave portions arranged along a long axis 2 on a heat transfer surface 1, the long axis 2 is a central line along a length direction of the heat transfer surface 1, each of the V-shaped convexo-concave portions includes convex strips 3a and concave strips 3b, the convex strips 3a and the concave strips 3b are alternately arranged, and convex peaks 4a and concave peaks 4b of the V-shaped convexo-concave portions are alternately arranged along the long axis 2 at a distance L, wherein L is greater than or equal to 0.4mm and less than or equal to 0.8mm. L can be any value within the above range. The processing technology of the V-shaped fin adopts continuous punch forming or hobbing machine roll forming.

Specifically, first inclined planes 5a and second inclined planes 5b are formed between the convex strips 3a and the concave strips 3b of each V-shaped concave-convex, the first inclined planes 5a have a small inclination angle and a large width, and the second inclined planes 5b have a large inclination angle and a small width. The first inclined surfaces 5a and the second inclined surfaces 5b are alternately arranged along the direction of the long axis 2, and the flow (secondary flow) of air in the X-axis direction is enhanced due to the difference of the inclination angle and the width of the two inclined surfaces; meanwhile, the first inclined surfaces 5a and the second inclined surfaces 5b are alternately arranged in the short axis 6 direction. Wherein the minor axis 6 is a center line along the width direction of the heat transfer surface 1. The flow of air in the Y-axis direction (secondary flow) is enhanced due to the difference in the inclination and width of the two inclined surfaces.

Further, the convex strip 3a of each V-shaped concave-convex is V-shaped and symmetrically arranged, and the concave strips 3b are V-shaped and symmetrically arranged. And the distances from the convex top point 3a and the concave top point 3b to the long axis 2 are equal.

As shown in fig. 10, is a velocity vector diagram of the V-shaped fin of the present invention. The existing wave-shaped fin has stable flow on a flow section, a temperature boundary layer is stable, and heat exchange is poor (as shown in figure 3). The V-shaped fin forms a plurality of vortexes due to the combined action of the secondary flow in the X-axis direction and the secondary flow in the Y-axis direction, enhances the forced convection between the middle and the side surface, further destroys a temperature boundary layer and a speed boundary layer, and strengthens the heat exchange performance.

Fig. 11 shows a temperature cloud of the V-shaped fin of the present invention. As can be seen from the figure, the V-shaped protrusions and recesses staggered from each other along the major axis 2 further strengthen the secondary flow, so that the small low-temperature regions 9 at both ends are further reduced compared with the conventional V-shaped fins, thereby further enhancing the heat exchange performance.

As shown in fig. 12 and 13, fig. 12 is a sectional view of a corrugated fin, and fig. 13 is a sectional view of a fin according to the present invention. Comparing the two figures, it can be seen that there is a distinct stagnant zone 20 in FIG. 12, whereas the V-shaped fin of the present invention has a smooth transition without substantial irregularities, inhibits the stagnant zone from occurring, and has a lower wind resistance at the same wind speed.

In addition, as shown in fig. 7, 8 and 9, the present invention has a chamfer 7 at the bending position. On the one hand, the chamfer 7 can greatly improve the manufacturability because the right-angled structure has poor machinability and affects demoulding, and the inclined chamfer can avoid the defects; on the other hand, a small flat area is formed at the position of the chamfer 7, so that the ventilation resistance is low, the air flow rate is high, dust can be taken away, and the dust removal effect is enhanced.

It is another object of the present invention to provide a heat exchanger comprising a fin for a heat exchanger as described above.

As shown in fig. 14, the fin of the present invention is disposed between two radiating pipes 8 (or radiating plates) disposed at intervals to constitute a heat exchange core of a heat exchanger. Wherein the interior of the radiating pipe 8 is communicated with hot fluid, the fins are communicated with cold air, and the air flows to the direction along the positive V direction as shown by the arrows in the figure.

The specific embodiments described herein are merely illustrative of the spirit of the invention. Various modifications or additions may be made to the described embodiments or alternatives may be employed by those skilled in the art without departing from the spirit or ambit of the invention as defined in the appended claims.

Claims

1. A fin for a heat exchanger, characterized by: the heat transfer surface (1) is provided with a plurality of V-shaped concave-convex parts arranged along the long shaft (2), the long shaft (2) is a central line along the length direction of the heat transfer surface (1), each V-shaped concave-convex part comprises convex strips (3 a) and concave strips (3 b), the convex strips (3 a) and the concave strips (3 b) are alternately arranged, convex peaks (4 a) and concave peaks (4 b) of the V-shaped concave-convex parts are mutually staggered along the long shaft (2), and the staggered distance is L;

first inclined planes (5 a) and second inclined planes (5 b) which are alternately arranged are formed between the convex strips (3 a) and the concave strips (3 b) of each V-shaped concave-convex part, the inclination angle of the first inclined plane (5 a) is small, the width of the first inclined plane is large, and the inclination angle of the second inclined plane (5 b) is large, and the width of the second inclined plane is small.

2. A fin for a heat exchanger as claimed in claim 1, wherein: the first inclined surfaces (5 a) and the second inclined surfaces (5 b) are alternately arranged along the direction of the long axis (2).

3. A fin for a heat exchanger as claimed in claim 2, wherein: the first inclined planes (5 a) and the second inclined planes (5 b) are alternately arranged along the direction of a short shaft (6), and the short shaft (6) is a central line along the width direction of the heat transfer surface (1).

4. A fin for a heat exchanger as claimed in claim 1, wherein: the bent part of the heat transfer surface (1) is provided with a chamfer (7) for improving manufacturability and strengthening dust removal.

5. A fin for a heat exchanger as claimed in claim 1, wherein: convex strips (3 a) of each V-shaped concave-convex are V-shaped and symmetrically arranged, and concave strips (3 b) are V-shaped and symmetrically arranged.

6. A fin for a heat exchanger as claimed in claim 1, wherein: the staggered distance: l is more than or equal to 0.4mm and less than or equal to 0.8mm.

7. A fin for a heat exchanger as claimed in claim 1, wherein: the distances from the convex top point (3 a) and the concave top point (3 b) to the long axis (2) are equal.

8. A heat exchanger, characterized by: comprising a fin for a heat exchanger according to claims 1-7.