JPH07280479A - Heat exchanger with fins - Google Patents

Abstract

(57) [Summary] [Purpose] To eliminate dead water areas on the fin surface downstream of the heat transfer tubes of waffle type finned heat exchangers such as cross fin heat exchangers. [Structure] For example, two or more ridges 6A, 6B per row
In the waffle-shaped cross fin 1 having the above-mentioned structure, the air flow A is circulated by forming the air flow guide concave portion 10 and the flat surface 5a in the downstream direction of the seat 5 of the fin collar 3, or the front half 11A of the seat 11 is formed. And the second half 11B
The turbulent flow promoting effect is realized by forming the step portion 11C by making the diameters r ₁ and r ₂ of the heat transfer tube 2,
2 ... The dead water area on the downstream side was reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the structure of a finned heat exchanger such as a cross fin heat exchanger for an air conditioner.

[0002]

2. Description of the Related Art Conventionally, in a finned heat exchanger such as a cross fin heat exchanger, when the frosted state of the fin portion is observed during heating operation, as shown in FIGS. 5 and the heat transfer tube 2 and the heat transfer tube 2
During this period, a considerable amount of frost is observed on the outer periphery of the seat 5 of the fin collar 3, but on the other hand, there is little frost on the downstream rear portion of the seat 5 of the fin collar 3.

This indicates that the flow of the air flow stagnates in the same portion and forms a dead water region S, which does not contribute much to heat exchange.

This tendency is particularly remarkable in the case of the waffle fin as shown in which the peak portions 6A and 6B extending in the longitudinal direction are formed in front of and behind the heat transfer tube 4 of the fin portion.

In view of such circumstances, for example, Japanese Unexamined Patent Publication No.
As shown in Japanese Patent No. 268195, in the above waffle fin having a plurality of peaks in the direction from the upstream side to the downstream side of the air flow, the seat portion of the fin collar is formed in an elliptical shape elongated in the air flow circulation direction. At the same time, a heat exchanger with fins is formed by forming a mountain-shaped structure at the upper and lower portions or front and rear outer peripheral portions of the fins so as to guide the air flow to the rear of the fin collar so as to prevent the above dead water region as much as possible. Is proposed.

26 and 27 show the structure of the fin portion of the heat exchanger with fins.

In the figure, 1 is a fin, 12 is a heat transfer tube, 13 is a fin collar, A is an air flow, and 15 is an elliptical seat whose short axis extends in the step direction and whose long axis extends in the air flow direction. Is. At the outer peripheral portion on the minor axis side and the outer peripheral portion on the major axis downstream side of the seat 15, along the outer peripheral edge thereof, the seat side mountain portions 17, 1
8 is formed. Also, the seat side mountain portion 1 of the fin 1
On the outside of 7,18, the fin-side mountain portion 16 is a straight line whose ridge line extends in the step direction at approximately the same height as the fin-side mountain portions 17,18.
Two A and 16B are formed for each row pitch, and the seat-side ridges 17 and 18 are fin-side ridges 16A and 16A, respectively.
It is formed between the peaks of 16B, 16B and 16A.

According to this structure, first, the heat transfer performance is improved by the turbulent flow promoting effect of the fin side peaks 16A and 16B, and the air flow A is further transferred to the fin collar 13 by the seat side peaks 17 and 18. It is expected that the heat exchange performance will be improved because the dead water area introduced to the rear part is reduced and the effective heat transfer area is increased.

[0009]

However, the configuration of the above conventional example has the following problems.

(1) The seat itself is a concave portion, and only the outer peripheral portion on the minor axis side and the outer peripheral portion on the downstream major axis are ridges, and the concave seat extends to the fin trailing edge side. It is the same as it was expanded in the direction, and again there is a dead water area behind the fin collar.

(2) Further, the relative ventilation amount of the air is increased by the relative unevenness amount of the concave portion and the mountain portion, which does not always contribute effectively to the improvement of the heat exchange performance.

The present invention has been made to solve the above problems, and improves the seat portion around the fin collar of the fin or the rear fin structure continuous with the seat portion to improve the fin collar rearward. It is an object of the present invention to provide a heat exchanger with fins, which makes the air flow wrap around well and prevents the generation of dead water areas as in the conventional case.

[0013]

In order to effectively achieve the above object, the present invention comprises the following means for solving problems.

That is, the heat exchanger with fins of the present invention has at least two peaks 6A, 6B extending in the longitudinal direction of the fins on the upstream side and the downstream side of the air flow A and located between the peaks 6A, 6B. In the heat exchanger with fins in which the fin collar 3 for closely inserting the heat transfer tube is provided and the seat 5 is formed around the fin collar 3, a state in which the fin 5 is flush with the seat surface behind the seat 5. Is formed by forming a flat surface extending downstream.

The flat surface 5a is formed such that the width in the fin longitudinal direction is substantially equal from the upstream side to the downstream side of the air flow, or the width in the longitudinal direction of the fin is small from the upstream side to the downstream side of the air flow. Is formed.

Further, the fin 1 is formed by integrally molding the fin collar 3, the seat 5 and the flat surface 5a by press working, and is also made of an aluminum material, and its surface is subjected to hydrophilic treatment.

On the other hand, the heat exchanger with fins of the present invention has at least two peaks 6A, 6B extending in the fin longitudinal direction on the upstream side and the downstream side of the air flow A, and between the peaks 6A, 6B. In the heat exchanger with fins, which is provided with the fin collar 3 for closely inserting the heat transfer tube, and the seat 5 is formed around the fin collar 3, the diameter r ₁ of the seat front half 11A of the seat 11 is And the diameter r ₂ of the latter half portion 11B are different.

In the structure, the seat 11 is
The diameter r ₁ of the front half 11A is formed larger than the diameter r ₂ of the rear half 11B, or conversely, the diameter r ₂ of the rear half 11B is formed larger than the diameter r ₁ of the front half 11A.

Furthermore, the heat exchanger with fins of the present invention is also configured as follows.

That is, the finned heat exchange is provided between the upstream side and the downstream side of the air flow A, the fin collar 3 for closely inserting the heat transfer tube is provided, and the seat 51 is formed around the fin collar 3. In the container, the seat 51 is located behind the seat 51.
Is divided into upper and lower portions, and the upper and lower edge portions 52a and 52b of the divided portion 52 can entrain the airflow A.

In the structure, a waffle type fin or a trapezoidal type fin structure is arbitrarily adopted as the fin 1.

[0022]

In the heat exchanger with fins of the present invention, as described above, first, at least two peaks 6A, 6B extending in the fin longitudinal direction are provided on the upstream side and the downstream side of the air flow A, and the peaks 6A, 6B, a fin collar 3 for closely inserting the heat transfer tube is provided, and a seat 5 is formed around the fin collar 3.
A flat surface that extends to the downstream side in the same plane as the seat surface is formed behind the flat surface. Therefore, in this structure, the air flow A on the upstream side of the fin collar 3 effectively wraps around to the rear side by the flat surface.

As a result, the dead water area behind the fin collar 3 is reduced and the effective heat transfer area of the fin 1 is expanded.

In that case, if the flat surface 5a is formed such that the width in the fin longitudinal direction is substantially equal from the upstream side to the downstream side of the air flow, the fin collar 3 is formed.
The airflow A circling to the rear of the fin uniformly flows in the longitudinal direction of the fin on a flat surface having a substantially equal diameter and a large area, thereby improving the heat transfer performance.

In the same construction, the flat surface 5
When a is formed so that the width in the fin longitudinal direction becomes smaller from the upstream side to the downstream side of the air flow, the air flow from both upper and lower sides of the seat 5 is guided to the rear of the fin collar 3,
The effect of introducing the airflow A into the dead water area on the rear side of the fin collar 3 is enhanced, and the airflow A can be more effectively circulated around the dead water area generation center portion, and the heat transfer performance is improved. Get better

Further, in the same configuration, the fin 1 described above is used.
However, if the fin collar 3, the seat 5, and the flat surface 5a are integrally formed by press working, the manufacturing and processing are simple and the cost can be reduced.

Further, in the same structure, the fin 1 is
When it is made of aluminum and its surface is subjected to hydrophilic treatment, it is lightweight, easy to process, has high heat transfer performance, and is unlikely to cause water splash due to dew condensation.

On the other hand, as a configuration different from the above, the air flow A
Has at least two peaks 6A, 6B extending in the longitudinal direction of the fins on the upstream side and the downstream side of the peaks 6A, 6B.
In the heat exchanger with fins, which is provided between the fins 3 for closely inserting the heat transfer tube and the seat 5 is formed around the fin collar 3, a front half 11 of the seat 11 is provided.
Than those made different from the diameter r ₂ of the second half portion 11B and the diameter r ₁ of A, step portion is formed on the top and bottom of the fin collar 3 by diameter r _1, r ₂ different loci 11 before and after, with stepped portions Due to the turbulent flow promoting action, the airflow A circulates to the rear of the fin collar 3 well, the dead water area is reduced, and the effective heat transfer area is expanded.

In that case, the seat 11
When the diameter r ₁ of the front half portion 11A is formed larger than the diameter r ₂ of the rear half portion 11B, the air flow A suddenly becomes smaller from the upstream side to the downstream side. Second half 1
When the diameter r _{2 of} 1B is formed to be larger than the diameter r ₁ of the first half 11A, the above-mentioned heat transfer area expanding action is achieved by the step portion in which the air flow A suddenly expands from the upstream side to the downstream side. Will be realized.

Further, as a configuration different from them,
In a heat exchanger with fins, which is provided between the upstream side and the downstream side of the air flow A, the fin collar 3 for closely inserting the heat transfer tube is provided, and the seat 51 is formed around the fin collar 3.
A split portion 52, which is obtained by vertically splitting the seat 51, is formed behind the seat 51, and the upper and lower edge portions 52a and 52b of the split portion 52 can entrain the airflow A.
The wraparound of the airflow A to the rear of the fin collar 3 becomes good, and the dead water area is reliably eliminated.

[0031]

As described above, according to the heat exchanger with fins of the present invention, the dead water area downstream of the fin collar seat can be effectively reduced, and the heat exchanger with fins having high heat exchange performance is provided. It becomes possible.

[0032]

【Example】

(Embodiment 1) Hereinafter, a finned heat exchanger according to Embodiment 1 of the present invention will be described in detail with reference to the drawings.

First, FIGS. 1 to 3 show a first embodiment of the present invention.
The fin part of the heat exchanger with a fin in is shown. In the figure, 1 is a fin, 2 is a heat transfer tube, 3 is a fin collar, 3a
Is a heat transfer tube fitting hole, 4 is an air flow, and 5 is a circular seat having the same minor axis and major axis lengths. The seat 5 is provided on the fin 1.
Two ridges 6A and 6B with ridge lines extending vertically before and after
And the seat 5 is formed in the valley 6C between the peaks of the peaks 6A and 6B.

From the front part to the rear part of the seat 5,
A concave portion 10 is formed in which the diameter in the vertical direction (fin fin longitudinal direction) is gradually reduced from the upstream side to the downstream side of the air flow A. The seat 5 is located in the recess 10, and a flat surface 5a is formed on the downstream side of the seat 5 so as to be gradually smaller in diameter and extend rearward while being flush with the seat surface of the seat 5.

Therefore, according to this structure, the heat transfer tubes 2,
2 ... The front air flow A is smoothly introduced from the upper and lower sides of the heat transfer tubes 2, 2 ... To the rear side, and is narrowed by the recesses 10 of the ridges 6A, 6B to flow behind the fins 1 by air resistance. The heat transfer tubes 2,2 ...
..The rear dead water area is effectively eliminated.

As a result, the entire fin 1 can be effectively contributed to the heat exchange, and the heat exchange performance is improved.

(Embodiment 2) In the structure of Embodiment 1 described above, the recess 10 and the flat surface 5a for the air flow guide are used.
The downstream end of the fin 1 is formed so as to converge at the rear edge position of the fin 1. The structure of the recess 10 and the flat surface 5a is, for example, as shown in FIGS. Even with a structure in which the rear edge side is opened to the same diameter or slightly enlarged, substantially the same operational effect can be realized.

(Embodiment 3) Next, FIGS. 7 to 9 show the structure of a heat exchanger with fins according to Embodiment 2 of the present invention.

In the figure, 1 is a fin, 2 is a heat transfer tube, 3 is a fin collar, 3a is a heat transfer tube fitting hole, and A is an air flow, which are the same as those in the first embodiment. .

On the other hand, 5A is a seat for fixing the heat transfer tube, and the function of itself is the same as that of the first embodiment, but in the case of this embodiment, the seat 11 has its front half portion 11A as shown in the drawing. And the rear half 11B side have different diameters r ₁ and r ₂ from each other, and the front half 11A is smaller than the diameter r ₂ of the rear half 11B.
Is formed by enlarging the diameter r ₁ thereof by a predetermined diameter Δr (for example, Δr = 3 mm).

As a result, according to this configuration, the step 11C is formed at the boundary between the front half 11A side and the rear half 11B side of the seat 11, the air flow A is effectively disturbed, and the heat transfer tubes 2, 2 ,.
・ It effectively wraps around to the rear side of, and the dead water area as before is reduced. Therefore, the effective heat transfer area of the fin 1 is expanded, and the entire fin can be effectively contributed to the heat exchange, so that the heat exchange performance is improved.

When the heat transfer ratio (B) according to the structure is compared with the case where the seat 5 as a whole has the same diameter (r ₁ = r ₂ ), for example, it becomes as shown in FIG. 13, and the effectiveness of the effect of the structure is confirmed. Was done.

(Embodiment 4) Further, FIGS. 10 to 12 relate to Embodiment 4 of the present invention in which the size relationship of the diameters of the front half 11A and the rear half 11B of the seat 11 of the above Embodiment 3 is reversed. The structure of the heat exchanger with a fin is shown.

Even with this structure, the seat 11
The air flow A is disturbed at the step 11D at the boundary between the front half 11A and the rear half 11B, and the air flow A effectively wraps around the rear of the heat transfer tubes 2, 2. Therefore, it is possible to realize the heat exchange performance improving effect which is substantially the same as that of the third embodiment.

Comparing the heat transfer ratio (A) of the structure with the case where the entire seat 5 has the same diameter (r ₁ = r ₂ ), for example, it becomes as shown in FIG. 13, and the effectiveness of the effect of the structure is confirmed. Was done.

In the first to fourth embodiments, it is needless to say that the number of the peak portions 16A, 16B of the fin 1 is not limited to two as described above and may be three or more. .

(Embodiment 5) Next, FIGS. 14 to 16 show the structure of a fin portion of a heat exchanger with fins according to Embodiment 5 of the present invention.

In the drawing, reference numeral 1 is a fin, 2 is a heat transfer tube, 3 is a fin collar, 3a is a heat transfer tube fitting hole, A is an air flow, and these are basically the cases of the above-mentioned first to fourth embodiments. Is the same as.

On the other hand, reference numeral 51 is a seat for fixing the heat transfer tube, and the basic function itself is the same as that of each of the above-mentioned embodiments, but especially in the case of this embodiment, different from the case of each of the above-mentioned embodiments. A rear portion of the seat surface portion is vertically divided into Y-shapes to form a division portion 52.

Therefore, the upper and lower edge portions 52a and 52b of the same divided portion 52 cause the air flow A flowing to the rear of the heat transfer tube to be respectively caught inside as shown by arrows (a) and (b). Dead water areas such as are less likely to occur. As a result, the entire fin 1 part can be more effectively contributed to the heat exchange, and the heat exchange performance is improved.

Then, the dividing section 52 in the present embodiment.
17 to 19 may be used, and the shape of the fin 1 is not limited to the waffle type as described above, but may be a trapezoidal cross section as shown in FIGS. 20 to 23. May be

[Brief description of drawings]

FIG. 1 is a side view of a fin portion of a heat exchanger with fins according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view of the fin portion taken along the line 1A-A of FIG.

FIG. 3 is a perspective view of the fin portion.

FIG. 4 is a side view of a fin portion of the heat exchanger with fins according to the second embodiment of the present invention.

FIG. 5 is a cross-sectional view of the fin portion taken along the line 4B-B of FIG.

FIG. 6 is a perspective view of the fin portion.

FIG. 7 is a side view of a fin portion of the heat exchanger with fins according to the third embodiment of the present invention.

FIG. 8 is a cross-sectional view of the fin portion taken along line 7C-C of FIG.

FIG. 9 is an enlarged view of the fin seat portion.

FIG. 10 is a side view of a fin portion of the heat exchanger with fins according to the fourth embodiment of the present invention.

FIG. 11 is a cross-sectional view of the fin portion taken along the line 10D-D.

FIG. 12 is an enlarged view of the fin seat portion.

FIG. 13 is a graph showing the relationship between the front half and rear half diameters r ₁ and r ₂ of the seats of Examples 3 and 4 and the heat transfer ratio.

FIG. 14 is a side view of a fin portion of the heat exchanger with fins according to the fifth embodiment of the present invention.

FIG. 15 is a view showing the fin portion of FIG.
It is a line sectional view.

FIG. 16 is a view showing the fin portion of FIG.
It is a line sectional view.

FIG. 17 is a side view of a fin portion of the heat exchanger with fins according to the sixth embodiment of the present invention.

FIG. 18 is a view showing the fin section GG of FIG. 17;
It is a line sectional view.

FIG. 19 is a H-H of FIG. 17 of the same fin part.
It is a line sectional view.

FIG. 20 is a side view of a fin portion of a finned heat exchanger according to a seventh embodiment of the present invention.

FIG. 21 is a sectional view of the fin portion taken along the line II of FIG. 20;
It is a line sectional view.

FIG. 22 is a view of the fin portion taken along line JJ of FIG. 20;
It is a line sectional view.

FIG. 23 is a view showing the fin section KK of FIG. 20.
It is a line sectional view.

FIG. 24 is a side view of a fin portion of a conventional general finned heat exchanger.

25 is a cross-sectional view taken along the line LL in FIG. 24.

FIG. 26 is a side view of a fin portion of a conventional finned heat exchanger.

27 is a cross-sectional view taken along line MM of FIG. 26.

[Explanation of symbols]

1 is a fin, 2 is a heat transfer tube, 3 is a fin collar, 5 is a seat,
Reference numeral 10 is a concave portion, 11 is a seat, 11A is a front half of the seat, 11B is a rear half of the seat, 51 is a seat, 52 is a split portion, and A is an air flow.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Isao Fujinami 1304 Kanaoka-cho, Sakai City, Osaka Prefecture Daikin Industries, Ltd.Kanaoka Factory, Sakai Factory (72) Kaori Yoshida 1304, Kanaoka-cho, Sakai City, Osaka Daikin Industry Co., Ltd. Sakai Plant Kanaoka Plant (72) Inventor Hiroyuki Yamashita 1304 Kanaoka Town, Sakai City, Osaka Prefecture Daikin Industries, Ltd. Sakai Plant Kanaoka Plant

Claims (9)

[Claims] 1. At least two longitudinally extending peaks (6A), (6B) are provided on the upstream side and the downstream side of the air flow (A) and are located between the peaks (6A), (6B). Fin collar (3) for closely inserting the heat transfer tube
In a finned heat exchanger having a seat (5) formed around (3), a flat surface (5a) extending downstream is formed behind the seat (5) so as to be flush with the seat surface. A heat exchanger with fins characterized by the above. 2. The heat with fins according to claim 1, wherein the flat surface (5a) is formed so that the width in the longitudinal direction of the fin is substantially equal from the upstream side to the downstream side of the air flow (A). Exchanger. 3. The heat exchanger with fins according to claim 1, wherein the flat surface (5a) is formed so that the width in the longitudinal direction of the fin is small from the upstream side to the downstream side of the air flow (A). 4. The fin (1) comprises a fin collar (3) and a seat.
(5) The flat surface (5a) is integrally formed by press working, and is formed.
The heat exchanger with fins described. 5. The heat exchanger with fins according to claim 1, 2, 3 or 4, wherein the fin (1) is made of an aluminum material, and the surface of which is subjected to hydrophilic treatment. 6. At least two longitudinally extending peaks (6A), (6B) are provided on the upstream side and the downstream side of the air flow (A) and are located between the peaks (6A), (6B). Fin collar (3) for closely inserting the heat transfer tube
In a finned heat exchanger having a seat (5) formed around (3), the diameter (r ₁ ) of the seat front half (11A) and the diameter (r ₁ ) of the rear half (11B) of the seat (11) are ₂ ) A heat exchanger with fins, which is different from that. 7. The seat (11) is characterized in that the diameter (r ₁ ) of the front half (11A) is larger than the diameter (r ₂ ) of the rear half (11B). Heat exchanger with fins. 8. The seat (11) is characterized in that the diameter (r ₂ ) of the rear half portion (11B) is larger than the diameter (r ₁ ) of the front half portion (11A). Heat exchanger with fins. 9. A fin collar (3) for closely inserting a heat transfer tube is provided between an upstream side and a downstream side of the air flow (A), and a seat (51) is provided around the fin collar (3). In the heat exchanger with fins formed, the seat is placed behind the seat (51).
A heat exchange with fins, characterized in that a division part (52) is formed by dividing the (51) into upper and lower parts, and the air flow (A) can be entrained by the upper and lower edge parts (52a), (52b). vessel.