JP2000154989A - Air heat exchanger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the performance of heat transfer to air of an air heat exchanger equipped with corrugated fins. SOLUTION: In an air heat exchanger constituted by providing a plurality of flat heat transfer tubes 2 and corrugated fins 4 alternately between headers 3, a plurality of cut-raised pieces 4a having a prescribed angle θ of inclination to the flowing direction of air are provided on fin surfaces of the corrugated fins 4. In the condition that the air heat exchanger can be manufactured with the angle θ of inclination of these cut-raised pieces 4a to the flowing direction of air made 25 deg.-40 deg. and the disposition pitch LP thereof made 0.5-0.9 mm, it can improve a heat transfer rate as much as possible without increasing draft resistance.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the structure of an air heat exchanger provided with corrugated fins.

[0002]

2. Description of the Related Art The entire structure of an air heat exchanger provided with corrugated fins and each part thereof is shown, for example, in FIGS.

As shown in FIG. 1, the air heat exchanger 1 has a pipe-shaped upper and lower header 3 through which a refrigerant is introduced and discharged.
A, 3B and the upper and lower headers 3A, 3B in communication with each other,
And a plurality of flat heat transfer tubes 2, 2... Arranged side by side at predetermined intervals in the longitudinal direction thereof and substantially in the vertical direction between the plurality of flat heat transfer tubes 2, 2. The corrugated fins 4, 4,... Are disposed in a state of being continuously bent in an S-shape, and the outer ends of the bent surfaces are heat-welded to the flat heat transfer surfaces of the corresponding flat heat transfer tubes 2, 2,.・ ・ It consists of

The flat heat transfer tubes 2, 2... Have a plurality of refrigerant flow holes 2a, 2
have a multi-hole structure, and the refrigerant introduced and distributed from the outside via the upper header 3A is caused to flow evenly into the respective refrigerant circulation holes 2a, 2a,. , Heat exchange between the internal refrigerant and the external air is performed in a wide heat transfer area.

The corrugated fins 4, 4...
As shown in FIGS. 3, 4 and 5, for example, the air flow A is a flat surface portion excluding the bent portion (bent portion), and the center is a flat flat portion 4c formed by processing.
A plurality of cut-and-raised pieces (louvers) 4a for improving the heat transfer efficiency with air to each of the upstream portion and the downstream portion of
Are formed, and the cut and raised pieces 4a, 4a are formed.
, The heat exchange performance between the refrigerant and the air is increased as much as possible.

Reference numerals 4b in FIGS. 4 and 5 denote a front edge of the flat portion of the corrugated fin 4 and 4d denotes a rear edge thereof.

[0007]

The specifications of the corrugated fins 4, 4,... Shown in FIGS.
For example, the fin width FW, the fin height FH, the length L of the entire fin, the thickness t, the arrangement pitch (louver pitch) LP of the cut and raised pieces 4a, 4a,. 1 It is determined concretely according to the overall dimensions and the conditions of the material used. Regarding the improvement of the air-side heat transfer performance, in particular, the cut and raised pieces (louvers) 4a, 4a,.
The mutual cut-and-raised piece arrangement pitch (louver pitch) LP and the inclination angle (cut-and-raise angle) θ are important determinants.

The following is a description of these two conditions.

First, if the pitch of the cut-and-raised pieces (louver pitch) LP is too large, the leading edge effect cannot be fully utilized, so that, for example, as shown in the characteristics of FIG. become worse. On the other hand, when the cut-and-raised piece arrangement pitch (louver pitch) LP is reduced, the leading edge effect can be utilized, but the height of the cut-and-raised pieces 4a, 4a,. (Louver height) LH, interval between cut-and-raised pieces 4a, 4a... (Louver interval) LM
Becomes small, and the cut-and-raised pieces (louvers) 4a, 4a,.
For example, the value of the heat transfer coefficient takes a certain maximum value with respect to the arrangement pitch (louver pitch) LP of the cut and raised pieces as shown in the characteristic of FIG. Become.

[0010] Further, cut and raised pieces (louvers) 4a, 4a.
When the inclination angle (cut-and-raise angle) θ is small, the height (louver height) of the cut-and-raised pieces 4a shown in FIG.
LH, the cut-and-raised pieces (louvers) 4 because the distance (louver distance) LM between the cut-and-raised pieces 4a, 4a,.
Air hardly flows between a, 4a,..., and the heat transfer coefficient is not good, for example, as shown in the characteristics of FIG.

[0011] The ventilation resistance also shows a tendency substantially similar to the heat transfer coefficient. On the other hand, as shown in FIG. 8, the arrangement of the cut and raised piece pitches 4a, 4a,.
And the cut and raised piece 4 as shown in FIG.
There is a limit in the production of increasing the inclination angle (cutting angle) θ of a, 4a,.

The invention of this application has been made in order to solve such a problem, and an appropriate arrangement pitch LP and an inclination angle θ of the cut-and-raised pieces are set within a range of numerical conditions that can be manufactured. It is an object of the present invention to provide an air heat exchanger having an improved heat transfer coefficient on the air side by setting these two numerical values in an appropriate relationship.

[0013]

Means for Solving the Problems Each invention of this application is provided with the following means for solving the problems in order to achieve the object.

(1) The air heat exchanger according to the present invention has a plurality of flat heat transfer tubes 2, 2... And corrugated fins 4, 4,.
An air heat exchanger comprising a plurality of cut and raised pieces having a predetermined inclination angle θ in the air flow direction on the fin surfaces of the corrugated fins 4, 4,... 4
are provided, and the plurality of cut-and-raised pieces 4a, 4a,.
At 0 °, their disposition pitch LP is 0.5 mm to 0.9 mm.
mm.

As described above, in order to improve the air-side heat transfer performance of the corrugated fins 4, 4,..., The cut and raised pieces 4a, 4a. The setting pitch LP and the inclination angle θ due to the cut and raised are important determinants.

When the arrangement pitch LP of the cut-and-raised pieces 4a, 4a,... Is large, the heat transfer coefficient is deteriorated because the leading edge effect of the fin cannot be fully utilized as described above. . On the other hand, if the arrangement pitch LP is reduced, the leading edge effect of the fins can be utilized, but the height LH of the cut and raised pieces 4a, 4a,.
a, 4a... becomes small, and it becomes difficult for air to flow between the cut-and-raised pieces 4a, 4a. Therefore, the value of the heat transfer coefficient has a certain maximum value with respect to the arrangement pitch LP. Will be taken.

If the inclination angle θ, which is the angle of the cut and raised pieces 4a, is small, the cut and raised piece 4
a, 4a... height LH, cut and raised pieces 4a, 4a,.
・ The cut-and-raised pieces 4a, 4 because the distance LM between them becomes small.
Since the air hardly flows between a and so on, the heat transfer coefficient deteriorates.

Also, the ventilation resistance shows a tendency substantially similar to the heat transfer coefficient. On the other hand, cut and raised pieces 4a, 4a
.. Have a limitation in manufacturing with respect to making the arrangement pitch LP smaller than 0.5 and making the inclination angle θ which is the cut-and-raise angle larger than 40 °.

However, as described above, the inclination angle θ, which is the cut-and-raise angle of the plurality of cut-and-raised pieces 4a, 4a, of the corrugated fins 4, 4,. , Their arrangement pitch LP is 0.5 mm to 0.9
If it is set to mm, as understood from the characteristics of FIG. 10, for example, the heat transfer coefficient with air can be sufficiently improved in a range where the ventilation resistance is relatively small. as a result,
Heat exchange performance is also improved.

In addition, the inclination angle θ = 25 ° to 40 ° and the disposition pitch LP = 0.5 mm to 0.9 mm are set so that the appropriate cut-up angle and cut-up piece within the range of the numerical conditions that can be manufactured. Because of the arrangement pitch, it can be manufactured without any problem.

(2) The air heat exchanger of the present invention has a plurality of flat heat transfer tubes 2, 2... And corrugated fins 4, 4,.
An air heat exchanger comprising a plurality of cut and raised pieces having a predetermined inclination angle θ in the air flow direction on the fin surfaces of the corrugated fins 4, 4,... 4
are provided, and the plurality of cut-and-raised pieces 4a, 4a,.
At 5 °, their disposition pitch LP is 0.6 mm to 0.8 mm.
mm.

As described above, the corrugated fins 4,
In order to improve the air-side heat transfer performance of the cut-and-raised pieces 4a, 4a,.
Is an important determinant.

When the arrangement pitch LP is large,
Because the leading edge effect of the fins cannot be fully utilized, the heat transfer coefficient is poor. On the other hand, as the arrangement pitch LP is reduced, the leading edge effect of the fins can be utilized, but the height LH of the cut and raised pieces 4a, 4a,. ..The interval LM between them becomes smaller,
Since it becomes difficult for air to flow between the cut and raised pieces 4a, the value of the heat transfer coefficient takes a certain maximum value with respect to the arrangement pitch LP.

When the inclination angle θ, which is the angle of the cut and raised pieces 4a, 4a, is small, the height LH of the cut and raised pieces 4a, 4a,. Pieces 4a, 4a
... Pieces 4 that are cut and raised to reduce the interval LM between them
Since it becomes difficult for air to flow between a and 4a, the heat transfer coefficient deteriorates.

Also, the ventilation resistance shows a tendency substantially similar to the heat transfer coefficient. On the other hand, the cut and raised pieces 4a, 4
There is a limit in terms of manufacturing in terms of making the arrangement pitch LP of a ... smaller than 0.5 and making the inclination angle θ larger than 40 °.

However, as described above, the inclination angle θ of the plurality of cut and raised pieces 4a, 4a,... Of the corrugated fins 4, 4,. Is set to 0.6 mm to 0.8 mm, as can be understood from the characteristics of FIG. 10, for example, the increase in ventilation resistance is smaller than in the case of the first aspect of the present invention, and the heat transfer coefficient with air is sufficiently increased. Can be improved.
In addition, in the case of the inclination angle θ and the arrangement pitch LP, clogging due to drain water or dust hardly occurs while increasing the heat transfer coefficient as described above. As long as the heat transfer coefficient can be improved.
As a result, the heat exchange performance is more effectively improved.

Further, the inclination angle θ = 30 ° to 35 ° and the arrangement pitch LP = 0.6 mm to 0.8 mm are appropriate cut-and-raise angles and louver pitches within the range of numerical conditions that can be manufactured. Therefore, it can be manufactured without any problem.

(3) The third aspect of the present invention is the air heat exchanger according to the first or second aspect, wherein the plurality of cut-and-raised pieces (4a, 4a,...) Are provided.
・ Indicates the airflow upstream side and the airflow downstream side.
The inclination direction is reversed.

Therefore, the corrugated fins 4, 4
The air flow flowing from the front edge to the rear edge along the fin surface moves from one side to the other through the gap between the upstream cut and raised pieces 4a, 4a,. After that, it flows again from the other side to the original one side through the gap between the downstream cut and raised pieces 4a, 4a,..., And a plurality of cut and raised pieces 4a, 4a,. Air can flow through the portion particularly efficiently. As a result, the heat transfer coefficient is further improved.

(4) The air heat exchanger according to the fourth aspect of the present invention is the air heat exchanger according to the first, second or third aspect, wherein the headers 3, 3 and the flat heat transfer tubes 2, 2 are provided.
, And corrugated fins 4, 4, ... are each made of aluminum.

Therefore, it is possible to provide an air heat exchanger that is very light and lightweight and has high heat transfer performance.

(5) The air heat exchanger according to the fifth aspect of the present invention is the air heat exchanger according to the first, second, third or fourth aspect, wherein the air heat exchanger 1 is a refrigerant for an air conditioner. / Air heat exchanger.

Therefore, it is possible to provide a light-weight refrigerant / air / air heat exchanger for an air conditioner having high heat exchange performance.

[0034]

As a result, according to the air heat exchanger of the present invention, the corrugated fins having a simple and low-cost fin structure, high heat transfer performance, light weight and suitable for an air conditioner are provided. It is possible to provide an air heat exchanger.

[0035]

(Embodiment 1) FIG. 10 shows a sectional structure of a corrugated fin portion of an air heat exchanger provided with a corrugated fin according to Embodiment 1 of the present invention (claim). (Corresponds to the inventions of items 1, 3, 4, and 5).

The air heat exchanger 1 according to this embodiment has a basic configuration as shown in FIG. 1 described above, in which pipes are formed of aluminum upper and lower headers 3A, 3A through which a refrigerant is introduced and discharged.
B, a plurality of aluminum flat heat transfer tubes 2, 2,... Arranged in the header direction in communication with the upper and lower headers 3A, 3B and at a predetermined interval from each other; Are arranged in a state of being continuously bent in a substantially S-shape in the vertical direction between the flat heat transfer tubes 2, 2... Of the flat heat transfer tubes 2, 2. .. Are made of aluminum corrugated fins 4, 4.

Each of the flat heat transfer tubes 2, 2,... Has a predetermined width corresponding to the diameter of the upper and lower headers 3A, 3B as shown in FIG. 2
a, 2a,..., and the refrigerant introduced and distributed from the outside via the upper header 3A flows evenly into the respective refrigerant circulation holes 2a, 2a. , 4,..., Heat exchange is efficiently performed between the internal refrigerant and the external air in a wide heat transfer area.

As shown in FIG. 10, for example, the corrugated fins 4, 4,... Are flat flat portions excluding the bent portions (bent portions), and are formed by processing a flat flat portion 4c at the center. A plurality of cut-and-raised pieces (louvers) 4a, 4a,... For improving the heat transfer efficiency with air are provided at each of the upstream portion and the downstream portion of the air flow A as a center. Are formed in reverse, and the cut-and-raised pieces 4a, 4a,.
Is 25 ° to 40 °, and their disposition pitch LP is 0.5
mm to 0.9 mm.

In order to improve the heat transfer performance on the air side of the corrugated fins 4, 4,..., The pitch of the cut and raised pieces 4a, 4a. The tilt angle θ is an important determinant.

When the arrangement pitch LP is large,
Since the leading edge effect of the fin cannot be fully utilized, the heat transfer coefficient deteriorates, for example, as shown in the characteristics of FIG. On the other hand, when the arrangement pitch LP is reduced, the leading edge effect of the fin can be utilized, but the height LH of the cut and raised pieces 4a, 4a,. ., The air flow between the cut-and-raised pieces 4a, 4a,... Becomes difficult, and the value of the heat transfer coefficient is, for example, as shown in the characteristics of FIG. It takes a certain maximum value for the set pitch LP.

When the inclination angle θ, which is the cut-and-raised angle of the cut-and-raised pieces 4a, is small, the cut-and-raised piece 4
a, 4a... height LH, cut and raised pieces 4a, 4a,.
-Since the interval LM between them is small, it becomes difficult for air to flow between the cut and raised pieces 4a, 4a, and for example, the heat transfer coefficient is deteriorated as shown in the characteristics of FIG.

Further, the ventilation resistance shows almost the same tendency as the heat transfer coefficient. On the other hand, the cut and raised pieces 4a, 4a.
There is a limit in the production of reducing the arrangement pitch LP and increasing the inclination angle θ which is a cut-and-raise angle.

However, as described above, the inclination angle θ, which is the cut-and-raised angle of the plurality of cut-and-raised pieces 4a, 4a, of the corrugated fins 4, 4,. The arrangement pitch LP is 0.5 mm to 0.9 mm
Then, as understood from the characteristics of FIG. 10, the heat transfer coefficient with air can be sufficiently improved in a state where the ventilation resistance is relatively small.

Further, the inclination angle θ = 25 ° to 40 ° and the arrangement pitch LP = 0.5 mm to 0.9 mm are set at appropriate cutting angles and arrangement pitches within the range of numerical conditions that can be manufactured. Therefore, it can be manufactured without any problem.

The plurality of cut-and-raised pieces 4a, 4a,... In the above-described configuration are of the upstream air flow side and the air flow downstream side, and their inclination directions are reversed. ing.

Therefore, the corrugated fins 4, 4
The air flow flowing from the front edge 4b side to the rear edge portion 4d side along the fin surface of the fin surface causes the gap between the upstream cut-and-raised pieces 4a, 4a, as shown by the arrow in FIG. From one side to the other side, and then returns to the original one side again from the other side through the gap between the downstream cut and raised pieces 4a, 4a,. And began to flow,
Air flows particularly efficiently through the plurality of cut-and-raised pieces 4a. As a result, the heat transfer coefficient is further improved.

As a result, according to the air heat exchanger according to the first embodiment of the present invention, a heat exchanger having a simple and low-cost all-aluminum structure and having a light weight and high heat transfer performance corrugated fins is provided. It becomes possible to provide an exchanger, which is suitable as an air heat exchanger for an air conditioner.

(Embodiment 2) Further, the inclination angle θ and the arrangement pitch LP of the cut-and-raised pieces 4a, 4a... Of the corrugated fins 4, 4,.
In the second embodiment, for example, the inclination angle θ is 30 ° to 3 °.
5 °, and the arrangement pitch LP = 0.6 mm to 0.8 mm.

As described above, the corrugated fins 4, 4,.
.. The inclination angle θ of the cut and raised pieces 4a, 4a,.
３５35 °, and their disposition pitch LP is set to 0.6 mm to 0.3 mm.
With the configuration of 8 mm, as can be understood from the characteristics of FIG. 10, the heat transfer coefficient with air can be sufficiently improved in a state where the ventilation resistance is smaller than that of the first embodiment. Become.

In the case of the inclination angle θ and the arrangement pitch LP, clogging due to drain water or dust hardly occurs even if the heat transfer coefficient is increased as described above. The transmission rate can be improved as much as possible.

Further, the inclination angle θ = 30 ° to 35 ° and the arrangement pitch LP = 0.6 mm to 0.8 mm are set at appropriate cutting angles and arrangement pitches within the range of numerical values that can be manufactured. Therefore, it can be manufactured without any problem.

As a result, Embodiment 2 of the invention of this application
According to the air heat exchanger according to the above, it is also possible to provide a heat exchanger having a corrugated fin having a light weight and a high heat transfer performance, also with a simple and low-cost configuration made of all aluminum. It becomes more suitable as an air heat exchanger or the like.

[Brief description of the drawings]

FIG. 1 is a perspective view showing the overall structure of an air heat exchanger provided with corrugated fins.

FIG. 2 is a cross-sectional view of a flat heat transfer tube portion of the heat exchanger.

FIG. 3 is a perspective view of a corrugated fin portion of the heat exchanger.

FIG. 4 is a sectional view of the corrugated fin portion (A-
A).

FIG. 5 is a front view showing a fin surface of the corrugated fin.

FIG. 6 is a side view of the corrugated fin.

FIG. 7 is an enlarged sectional view of a main part of the corrugated fin.

FIG. 8 is a sectional view of a first sample example of the corrugated fin.

FIG. 9 is a sectional view of a second sample example of the corrugated fin.

FIG. 10 is a cross-sectional view showing a configuration of a corrugated fin portion of the air heat exchanger according to Embodiment 1 of the present invention.

FIG. 11 is a diagram showing a heat transfer coefficient performance and a ventilation resistance determined from the relationship between the arrangement pitch LP of the cut and raised pieces of each corrugated fin and the inclination angle θ in the configuration of the first embodiment and the configuration of the second embodiment. 7 is a characteristic graph showing a comparison with the case of another configuration.

[Explanation of symbols]

1 is a heat exchanger, 2 is a flat heat transfer tube, 3A is an upper header, 3
B is a lower header, 4 is a corrugated fin, and 4a is a cut-and-raised piece (louver).

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Junichi Shiramizu 1304 Kanaokacho, Sakai City, Osaka Daikin Industries, Ltd. Sakai Plant Kanaoka Plant

Claims (5)

[Claims] 1. A plurality of flat heat transfer tubes (2), (2) ... and corrugated fins (4), (4) ... are alternately arranged between headers (3), (3). The corrugated fins (4), (4),.
・ The fin surface has a predetermined inclination angle (θ) in the air flow direction
Are provided, and the plurality of cut-and-raised pieces (4a) are provided.
a), (4a)... indicate that the inclination angle (θ) is 25 ° to 4 °.
At 0 °, arrangement pitch (LP) is 0.5mm ~ 0.9mm
An air heat exchanger, characterized in that: 2. A plurality of flat heat transfer tubes (2), (2) ... and corrugated fins (4), (4) ... are alternately arranged between headers (3), (3). The corrugated fins (4), (4),.
・ The fin surface has a predetermined inclination angle (θ) in the air flow direction
Are provided, and the plurality of cut-and-raised pieces (4a) are provided.
a), (4a)... have an inclination angle (θ) of 30 ° to 3 °.
At 5 °, arrangement pitch (LP) is 0.6mm ~ 0.8mm
An air heat exchanger, characterized in that: 3. A plurality of cut and raised pieces (4a), (4a).
3. The air heat exchanger according to claim 1, wherein the air heat exchanger and the air flow downstream have opposite inclination directions. 4. Headers (3), (3), flat heat transfer tubes (2), (2), corrugated fins (4),
The air heat exchanger according to any one of claims 1 to 3, wherein (4) is made of aluminum. 5. The air heat exchanger (1) is a refrigerant / air heat exchanger for an air conditioner.
An air heat exchanger according to 2, 3, or 4.