JP4626422B2 - Finned tube heat exchanger - Google Patents

Description

  The present invention relates to a finned tube heat exchanger, in particular, heat transfer fins arranged in an air flow, and a plurality of heat transfer tubes inserted in the heat transfer fins and arranged in a direction substantially perpendicular to the flow direction of the air flow, It is related with the fin tube type heat exchanger provided with.

  Conventionally, in an air conditioner or the like, a heat transfer fin disposed in an air flow, and a plurality of heat transfer tubes inserted in the heat transfer fin and disposed in a direction substantially orthogonal to the flow direction of the air flow are provided. Fin tube type heat exchangers (ie, cross fin and tube type heat exchangers) are often used.

In such a finned tube heat exchanger, the purpose is to reduce the dead water area formed in the downstream side of the airflow direction of the heat transfer tube in the heat transfer fin, and to update the boundary layer in the heat transfer fin. As a heat transfer promotion method, a method may be employed in which guide fins that are widened toward the upstream side in the air flow direction are formed by cutting and raising at positions on both sides of the heat transfer tube on the heat transfer fin surface ( Patent Document 1).
JP-A-61-110889

  However, in the finned tube heat exchanger employing the above-described guide fins, the guide fins are formed by cutting and raising, so the strength of the heat transfer fins near the heat transfer tubes is reduced, and the heat transfer fins are transferred to the heat transfer fins. In the pipe expansion work when inserting and assembling the heat pipe, sufficient contact between the heat transfer fin and the heat transfer pipe cannot be performed, resulting in a problem that the heat exchange performance is lowered.

  The subject of this invention is obtaining the heat transfer promotion effect by the guide fin formed by cutting and raising, suppressing the strength fall of a heat transfer fin in a fin tube type heat exchanger.

A finned tube heat exchanger according to a first aspect of the present invention includes a heat transfer fin disposed in an air flow and a plurality of heat transfer tubes inserted in the heat transfer fin and disposed in a direction substantially orthogonal to the flow direction of the air flow. And. In the heat transfer fins, on both sides of each heat transfer tube, guide fins that expand toward the upstream side in the airflow direction are formed on the heat transfer fin surface by cutting and raising. The portion of the guide fin corresponding to each heat transfer tube of the heat transfer fin on the downstream side in the flow direction of the airflow has a waffle shape.

  In this fin-tube heat exchanger, guide fins are formed by cutting and raising the upstream portion of the heat transfer fin in the air flow direction (hereinafter referred to as the front edge portion), and the flow of air flow through the heat transfer fin guide fins By making the portion on the downstream side in the direction (hereinafter, referred to as the trailing edge side portion) a waffle shape, it is possible to suppress a decrease in strength of the heat transfer fin while obtaining a heat transfer promotion effect by the guide fin. As a result, in the pipe expansion work when assembling the finned tube heat exchanger, sufficient contact between the heat transfer fin and the heat transfer pipe is achieved even though the heat transfer fin has the guide fin formed by cutting and raising. The heat exchange performance can be improved.

A finned tube heat exchanger according to a second aspect of the present invention is the finned tube heat exchanger according to the first aspect of the present invention, wherein a part of the heat transfer fins in the waffle shape is an air flow in the vicinity of each heat transfer tube. Is formed on the rear side in the air flow direction of each heat transfer tube.

  In this fin tube type heat exchanger, because the guide wall portion for guiding the airflow near the heat transfer tube to the rear side in the flow direction of the heat transfer tube is formed on the rear edge side portion of the heat transfer fin having the waffle shape, The effect of reducing the dead water area can be obtained.

A finned tube heat exchanger according to a third aspect of the present invention includes a heat transfer fin disposed in an air flow, and a plurality of heat transfer tubes inserted in the heat transfer fin and disposed in a direction substantially orthogonal to the flow direction of the air flow. And. In the heat transfer fins, on both sides of each heat transfer tube, guide fins that expand toward the upstream side in the airflow direction are formed on the heat transfer fin surface by cutting and raising. The part of the heat transfer fin on the downstream side of the flow direction of the air flow of each guide fin has a bulging part that is bulged without cutting the heat transfer fin, and the air flow in the vicinity of each heat transfer pipe It is formed so as to guide the direction rear side .

  In this fin-tube heat exchanger, guide fins are formed by cutting and raising the upstream portion of the heat transfer fin in the air flow direction (hereinafter referred to as the front edge portion), and the flow of air flow through the heat transfer fin guide fins By forming the bulging portion in the direction downstream side portion (hereinafter referred to as the trailing edge side portion), it is possible to suppress the strength of the heat transfer fin from being lowered while obtaining the heat transfer promotion effect by the guide fin.

Moreover, in this fin tube type heat exchanger, the bulging portion formed on the rear edge side portion of the heat transfer fin is formed so as to guide the airflow in the vicinity of the heat transfer tube to the rear side in the flow direction of the airflow of the heat transfer tube. Therefore, the effect of reducing the dead water area can be obtained. As a result, in the pipe expansion work when assembling the finned tube heat exchanger, sufficient contact between the heat transfer fin and the heat transfer pipe is achieved even though the heat transfer fin has the guide fin formed by cutting and raising. The heat exchange performance can be improved.

A finned tube heat exchanger according to a fourth aspect of the present invention is the finned tube heat exchanger according to any one of the first to third aspects of the present invention, wherein the guide fin has a height toward the downstream side in the air flow direction. In this finned tube heat exchanger, the shape of the guide fin is gradually increased toward the downstream side in the air flow direction, thereby generating a vertical vortex behind the guide fin. Therefore, the heat transfer promotion effect by the guide fins can be further enhanced.

  As described above, according to the present invention, the following effects can be obtained.

  In 1st invention, it can suppress that the intensity | strength of a heat-transfer fin falls, obtaining the heat-transfer promotion effect by a guide fin.

  In the second invention, an effect of reducing the dead water area can be obtained.

The finned tube heat exchanger according to the third aspect of the present invention can suppress a decrease in the strength of the heat transfer fins while obtaining the heat transfer promotion effect by the guide fins. Moreover, the effect of reducing the dead water area can be obtained.

In the fourth aspect of the invention, since the vertical vortex can be generated behind the guide fin, the heat transfer promotion effect by the guide fin can be further enhanced.

  Hereinafter, embodiments of a finned tube heat exchanger according to the present invention will be described with reference to the drawings.

<First Embodiment>
The principal part of the finned-tube type heat exchanger 1 concerning 1st Embodiment of this invention is shown in FIGS. 1-4. Here, FIG. 1 is a cross-sectional view of the finned tube heat exchanger 1. FIG. 2 is a cross-sectional view taken along the line AA of FIG. 3 is a cross-sectional view taken along line BB in FIG. FIG. 4 is a perspective view showing a portion C of FIG.

(1) Structure of fin tube type heat exchanger The fin tube type heat exchanger 1 is a so-called cross fin and tube type heat exchanger, and mainly includes a plurality of heat transfer fins 2 and a plurality of heat transfer tubes 3. ing.

  The heat transfer fins 2 are arranged side by side in the plate thickness direction in a state in which the plane direction is generally along the flow direction of the airflow such as air. The heat transfer fin 2 has a flat plate-like portion on the upstream side in the airflow direction (hereinafter referred to as the front edge side portion 2a), and a portion on the downstream side in the airflow direction (hereinafter referred to as the rear edge side portion 2b). Has a waffle shape.

  The front edge side portion 2 a constitutes a portion from the foremost edge in the airflow direction of the heat transfer fin 2 to the approximate center in the airflow direction of the heat transfer fin 2.

  The rear edge side portion 2b alternates in the plate thickness direction between the central line portion 24, which is the last edge downstream of the leading edge side portion 2a in the airflow direction, and the last edge in the airflow direction of the heat transfer fin 2. Are bent into a ridge line 25 having a ridge line protruding to one side in the plate thickness direction of the heat transfer fin 2 and a valley portion 26 having a ridge line protruding to one side in the plate thickness direction of the heat transfer fin 2. And the peak part 27 which has the ridgeline which protrudes to the one side of the plate | board thickness direction of the heat-transfer fin 2 was formed in order toward the last edge of the flow direction of the airflow of the heat-transfer fin 2 from the center line part 24 sequentially. Part. A plurality of through holes 2c are formed in the heat transfer fin 2 at intervals in a direction substantially perpendicular to the airflow direction. In the present embodiment, these through holes 2c are formed on the center line portion 24 so as to straddle the front edge side portion 2a and the rear edge side portion 2b. A peripheral portion of the through hole 2 c is an annular collar portion 23 that protrudes to one side in the plate thickness direction of the heat transfer fin 2. And the collar part 23 is contact | abutting to the surface on the opposite side to the surface in which the collar part 23 of the heat transfer fin 2 adjacent in the plate | board thickness direction was formed, and predetermined spacing is provided between the plate | board thickness directions of each heat transfer fin 2. H is secured.

  The heat transfer tube 3 is a tube member through which a heat medium such as a refrigerant flows. The heat transfer tube 3 is inserted into the plurality of heat transfer fins 2 arranged side by side in the plate thickness direction, and in a direction substantially orthogonal to the airflow direction. Has been placed. Specifically, the heat transfer tube 3 passes through the through holes 2 c formed in the heat transfer fins 2, and comes into close contact with the inner surface of the collar portion 23 by tube expansion work during assembly of the fin tube heat exchanger 1. ing.

  The guide fins 21a that expand toward the upstream side in the airflow direction on both sides of the heat transfer tubes 3 (that is, the lower side and the upper side of the heat transfer tubes 3) are formed on the front edge portion 2a of the heat transfer fins 2. , 21b are formed on the surface of the heat transfer fin 2 by cutting and raising. The direction in which the guide fins 21 a and 21 b are cut and raised is the same as the protruding direction of the collar portion 23. Each of the guide fins 21a and 21b is formed so that its height gradually increases toward the downstream side in the airflow direction. In this embodiment, each guide fin 21a, 21b is substantially trapezoidal or substantially triangular (see FIG. 3, FIG. 3 is a diagram showing the guide fin 21b, but the guide fin 21a has the same shape. The maximum height h is lower than the height H of the collar portion 23. Further, the slit holes 22a and 22b formed in the heat transfer fin 2 when the guide fins 21a and 21b are cut and raised are arranged on the side farther than the heat transfer tube 3 with the guide fins 21a and 21b interposed therebetween.

  Further, a flat portion 28 is formed on the rear edge side portion 2 b of the heat transfer fin 2 so as to surround the outer peripheral portion of the collar portion 23 and forms the same surface as the front edge side portion 2 a. And the guide wall part 29 which guides the airflow of the heat exchanger tube 3 vicinity to the flow direction downstream of this heat transfer tube 3 is formed in the flow direction downstream of this flat part 28. As shown in FIG. The guide wall portion 29 rises in the protruding direction of the collar portion 23 so as to be connected to the surface formed by the center line portion 24, the mountain portion 25, and the valley portion 26 from the downstream edge portion of the flat portion 28 in the airflow direction. It is a substantially arc-shaped wall. Here, the guide wall portion 29 is formed such that the wall height increases from the central line portion 24 toward the mountain portion 25 and the wall height decreases from the mountain portion 25 toward the valley portion 26. Thereby, the airflow flowing in the vicinity of the heat transfer tube 3 is easily guided to the rear side of the heat transfer tube 3 by the guide wall portion 29.

(2) Features of the finned tube heat exchanger In the finned tube heat exchanger 1 configured as described above, the leading edge side portion 2a, which is the upstream portion of the heat transfer fin 2 in the airflow direction, is cut and raised. The guide fins 21a and 21b are formed, and the rear edge side portion 2b, which is the downstream portion of the guide fins 21a and 21b in the airflow direction of the heat transfer fin 2, is formed into a waffle shape, and the vicinity of the heat transfer tube 3 of the heat transfer fin 2 The strength of the portion is prevented from decreasing. For this reason, when the heat transfer tube 3 is brought into close contact with the inner surface of the collar portion 23 by the tube expansion work at the time of assembling the fin tube heat exchanger 1, deformation of the heat transfer fins 2 in the vicinity of the heat transfer tubes 3 can be suppressed. As a result, it is possible to suppress a decrease in adhesion between the heat transfer tube 3 and the inner surface of the collar portion 23. Thus, in the finned tube heat exchanger 1, it becomes possible to suppress the strength of the heat transfer fins 2 from being reduced while obtaining the heat transfer promotion effect by the guide fins 21a and 21b, and the heat exchange performance is improved. Can be increased.

  Further, the rear wall 2b of the heat transfer fin 2 having the waffle shape is formed with a guide wall portion 29 that guides the airflow in the vicinity of the heat transfer tube 3 to the rear side in the airflow direction of the heat transfer tube 3. The effect of reducing the water area can be obtained.

  Further, in the fin tube type heat exchanger 1, the shape of the guide fins 21a and 21b is formed such that the height gradually increases toward the downstream side in the flow direction of the airflow, so that the back of the guide fins 21a and 21b. Since the vertical vortex can be generated, the heat transfer promoting effect by the guide fins 21a and 21b can be further enhanced.

<Second Embodiment>
The main part of the finned-tube heat exchanger 101 concerning 2nd Embodiment of this invention is shown in FIGS. Here, FIG. 5 is a cross-sectional view of the finned tube heat exchanger 101. 6 is a cross-sectional view taken along the line AA in FIG. FIG. 7 is a perspective view showing a portion C of FIG.

(1) Configuration of Fin Tube Type Heat Exchanger The fin tube type heat exchanger 101 is a so-called cross fin and tube type heat exchanger, and mainly includes a plurality of plate-shaped heat transfer fins 102 and a plurality of heat transfer tubes 3. And. The heat transfer fins 102 are arranged side by side in the plate thickness direction in a state in which the plane direction is generally along the flow direction of the airflow such as air. A plurality of through holes 102c are formed in the heat transfer fins 102 at intervals in a direction substantially orthogonal to the airflow direction. A peripheral portion of the through hole 102 c is an annular collar portion 123 that protrudes to one side in the plate thickness direction of the heat transfer fin 102. The collar portion 123 is in contact with a surface opposite to the surface on which the collar portion 123 of the heat transfer fins 102 adjacent to each other in the plate thickness direction is formed, and a predetermined interval H is provided between the plate thickness directions of the heat transfer fins 102. Secured. The heat transfer tube 3 is a tube member through which a heat medium such as a refrigerant flows. The heat transfer tube 3 is inserted into a plurality of heat transfer fins 102 arranged side by side in the plate thickness direction, and in a direction substantially perpendicular to the airflow direction. Has been placed. Specifically, the heat transfer tube 3 passes through the through holes 102 c formed in the heat transfer fins 102, and is brought into close contact with the inner surface of the collar portion 123 by the tube expansion work at the time of assembling the fin tube type heat exchanger 101. ing.

  Next, the detailed shape of the heat transfer fin 102 used in the finned tube heat exchanger 101 of the present embodiment will be described.

  And in the part (henceforth a front edge side part) of the flow direction upstream of the airflow of the heat transfer fin 2, the airflow of both sides of each heat transfer tube 3 (namely, the lower side and the upper side of each heat transfer tube 3). Guide fins 121a and 121b that expand toward the upstream side in the flow direction are formed on the surface of the heat transfer fin 102 by cutting and raising. The direction in which the guide fins 121 a and 121 b are cut and raised is the same as the protruding direction of the collar portion 123. Each of the guide fins 121a and 121b is formed so that its height gradually increases toward the downstream side in the airflow direction. In the present embodiment, each of the guide fins 121a and 121b has a substantially trapezoidal shape or a substantially triangular shape (see FIG. 3, FIG. 3 is a view showing the guide fin 121b, but the guide fin 121a has the same shape. The maximum height h is lower than the height H of the collar portion 123. Further, the slit holes 122a and 122b formed in the heat transfer fin 102 when the guide fins 121a and 121b are cut and raised are arranged on the side farther than the heat transfer tube 3 with the guide fins 121a and 121b interposed therebetween.

  The downstream portion of the front edge side portion of the heat transfer fin 102 in which the guide fins 121a and 121b are formed (hereinafter referred to as the rear edge side portion) is a portion on the outer peripheral side of the collar portion 123 and the flow of airflow. Enlarged portions 129a and 129b are formed by enlarging the heat transfer fins 102 by cutting or the like so as to surround a portion corresponding to the downstream side in the direction. The bulging portions 129 a and 129 b are substantially arc-shaped portions protruding in the same direction as the protruding direction of the collar portion 123. The bulging portion 129a is disposed on the side where the guide fin 121a is formed with respect to a line that crosses the tube center of the heat transfer tube 3 in the airflow direction. The bulging portion 129b is disposed on the side where the guide fins 121b are formed with respect to a line crossing the tube center of the heat transfer tube 3 in the airflow direction. For this reason, the airflow flowing in the vicinity of the heat transfer tube 3 is guided to the rear side in the airflow direction of the heat transfer tube 3 by the bulging portions 129a and 129b. Further, since a gap is provided between the downstream end of the bulging portion 129a in the airflow direction and the end of the bulging portion 129b on the downstream side in the airflow direction, the rear side of the heat transfer tube 3 is provided. It is easy to be guided to.

(2) Features of the Finned Tube Heat Exchanger In the finned tube heat exchanger 101 configured as described above, guidance is provided by cutting and raising the leading edge side portion that is the upstream side of the heat transfer fin 2 in the airflow direction. The bulging part 129a which formed the fins 121a and 121b and bulged without cutting the heat transfer fins 102 into the rear edge side part which is the downstream part of the guide fins 121a and 121b in the air flow direction of the heat transfer fins 102, By forming 129b, the strength of the heat transfer fins 102 in the vicinity of the heat transfer tubes 3 is prevented from decreasing. For this reason, when the heat transfer tube 3 is brought into close contact with the inner surface of the collar portion 123 by the tube expansion work at the time of assembling the finned tube heat exchanger 101, deformation of the heat transfer fins 102 in the vicinity of the heat transfer tubes 3 can be suppressed. As a result, it is possible to suppress a decrease in adhesion between the heat transfer tube 3 and the inner surface of the collar portion 123. Thus, in the fin tube type heat exchanger 101, it becomes possible to suppress the strength of the heat transfer fins 102 from being lowered while obtaining the heat transfer promotion effect by the guide fins 121a and 121b, and the heat exchange performance is improved. Can be increased.

  Further, the bulging portions 129a and 129b formed on the rear edge side portion of the heat transfer fin 102 are formed so as to guide the airflow in the vicinity of the heat transfer tube 3 to the rear side in the flow direction of the airflow of the heat transfer tube 3, The effect of reducing the dead water area can be obtained.

  Further, in the fin tube type heat exchanger 101, the shape of the guide fins 121a and 121b is formed so that the height gradually increases toward the downstream side in the flow direction of the airflow, so that the back of the guide fins 121a and 121b. Since the vertical vortex can be generated, the heat transfer promotion effect by the guide fins 121a and 121b can be further enhanced.

<Other embodiments>
As mentioned above, although embodiment of this invention was described based on drawing, a specific structure is not restricted to these embodiment, It can change in the range which does not deviate from the summary of invention.

  By utilizing the present invention, in the finned tube heat exchanger, it is possible to obtain the heat transfer promotion effect by the guide fin formed by cutting and raising while suppressing the strength reduction of the heat transfer fin.

It is sectional drawing of the fin tube type heat exchanger concerning 1st Embodiment of this invention. It is AA sectional drawing of FIG. It is BB sectional drawing of FIG. 1, FIG. It is a perspective view which shows the C section of FIG. It is sectional drawing of the fin tube type heat exchanger concerning 2nd Embodiment of this invention. It is AA sectional drawing of FIG. It is a perspective view which shows C part of FIG.

DESCRIPTION OF SYMBOLS 1,101 Fin tube type heat exchanger 2,102 Heat transfer fin 3 Heat transfer tube 21a, 21b, 121a, 121b Guide fin 29 Guide wall part 129a, 129b Swelling part

Claims (4)

A heat transfer fin (2) disposed in the air stream;
A plurality of heat transfer tubes (3) inserted in the heat transfer fins and arranged in a direction substantially perpendicular to the flow direction of the airflow;
In the heat transfer fins, guide fins (21a, 21b) that are widened toward the upstream side in the airflow direction are formed on the heat transfer fin surface by cutting and raising on both sides of each heat transfer tube. ,
A portion of the guide fin corresponding to each of the heat transfer tubes on the downstream side in the airflow direction of the guide fin has a waffle shape.
Fin tube heat exchanger (1). Some of the parts that have become waffle shape of the heat transfer fins (2), said each heat transfer tube (3) in the vicinity of the air flow, the guide wall portion for guiding the rear flow side of the air flow of the heat transfer tube The finned tube heat exchanger (1) according to claim 1, forming (29). A heat transfer fin (102) disposed in the air stream;
A plurality of heat transfer tubes (3) inserted in the heat transfer fins and arranged in a direction substantially perpendicular to the flow direction of the airflow;
In the heat transfer fins, guide fins (121a, 121b) that expand toward the upstream side in the air flow direction are formed on the heat transfer fin surface by cutting and raising on both sides of each heat transfer tube. ,
The said flow direction downstream side of the portion of the airflow of the guide fins of the heat transfer fins, the bulging portion which is bulged without cutting the heat transfer fins (129a, 129b) is the air flow of the heat transfer tube near Is formed to guide the rear side of the air flow direction of each heat transfer tube ,
Fin tube type heat exchanger (101). The fin-tube heat exchanger (1) according to any one of claims 1 to 3 , wherein the guide fins (21a, 21b, 121a, 121b) gradually increase in height toward the downstream side in the airflow direction. 101).

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