JP2022027996A - Heat radiation fin and heat exchanger including the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat radiation fin which can achieve higher heat exchange efficiency, and to provide a heat exchanger including the heat radiation fins.

SOLUTION: A heat radiation fin used in a heat exchanger includes: a plate-like fin body; through holes which are formed in the fin body and through which heat transmission pipes included in the heat exchanger with the fins respectively penetrate; and joint parts each of which is formed protruding from a peripheral edge of the through hole in a vertical direction relative to one surface of the fin body at one surface side of the fin body and has a short cylinder shape. In an entire area of an inner peripheral surface in the joint part having the short cylinder shape, its diameter does not change along an axial direction of the joint part and has the same dimension. Thus, the inner peripheral surface is formed as a straight surface which slidably fits in an outer peripheral surface of the heat transmission pipe.

SELECTED DRAWING: Figure 4

COPYRIGHT: (C)2022,JPO&INPIT

Description

The present invention relates to a heat dissipation fin and a heat exchanger provided with the heat dissipation fin.

Conventionally, as a heat exchanger with fins, a heat exchanger having a plurality of heat transfer tubes penetrating through a plurality of heat radiation fins arranged at predetermined intervals is known. Further, as shown in the explanatory view of FIG. 13, a short cylindrical joint portion 33 projecting along the penetration direction is provided on the peripheral edge of the through hole 32 provided in each heat radiation fin 3, and the joint portion 33 is provided. The heat transfer tube 2 is configured to be fitted externally to the portion 33. In such a heat exchanger, heat is transferred by transferring the heat of the fluid flowing in the heat transfer tube 2 to the gas flowing on the surface of the heat radiation fins via the heat radiation fins 3.

In order to improve the heat exchange efficiency by the heat exchanger, it is necessary to reduce the heat transfer loss between the heat transfer tube 2 and the heat radiation fin 3 as much as possible. However, in the conventional heat exchanger, the heat radiation fin 3 has. There is a problem that the degree of adhesion between the joint portion 33 and the heat transfer tube 2 is low, and it is difficult to effectively reduce the heat transfer loss. Specifically, as shown in FIG. 13, the form of the joint portion 33 externally fitted to the surface of the heat transfer tube 2 is formed in a tapered shape that reduces the diameter from the peripheral edge of the through hole 32 toward the protrusion direction. Therefore, the portion of the joint portion 33 that is substantially in close contact with the surface of the heat transfer tube 2 is the tip portion of the joint portion 33 in the projecting direction, and the heat transfer loss is large.

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a heat dissipation fin capable of exhibiting even higher heat exchange efficiency and a heat exchanger provided with the heat radiation fin.

The object of the present invention is a heat radiation fin used in a heat exchanger, which is a plate-shaped fin body, a through hole formed in the fin body and through which a heat transfer tube included in the finned heat exchanger penetrates, and the above. A short tubular joint formed by projecting from the peripheral edge of the through hole on one surface side of the fin body in a direction perpendicular to one surface of the fin body is provided, and the short tubular joint is provided. The entire area of the inner peripheral surface of the portion is configured to have the same dimensions without changing its diameter along the axial direction of the joint portion, and is a straight that slidably fits with the outer peripheral surface of the heat transfer tube. Achieved by heat dissipation fins characterized by being formed as a surface.

Further, the above object of the present invention is a heat exchanger provided with a plurality of the heat radiation fins described above, and includes a plurality of heat transfer tubes and a plurality of the heat radiation fins arranged at predetermined intervals. Each of the heat dissipation fins is achieved by a heat exchanger arranged so as to penetrate the heat transfer tube through the joint portion.

Further, in the heat exchanger, the ratio of the inner diameter of the joint portion to the outer diameter of the heat transfer tube (inner diameter of the joint portion / outer diameter of the heat transfer tube) is preferably 0.970 or more.

According to the present invention, it is possible to provide a heat radiation fin capable of exhibiting even higher heat exchange efficiency and a heat exchanger provided with the heat radiation fin.

It is a schematic block diagram of the heat exchanger which concerns on this invention. It is an enlarged sectional view of the main part of FIG. It is a main part plan view of the heat dissipation fin provided in the heat exchanger which concerns on this invention. FIG. 3 is an enlarged cross-sectional view of a main part of FIG. It is explanatory drawing for demonstrating the structure of the joint part provided with the radiating fin. It is explanatory drawing for demonstrating the effect of the heat exchanger which concerns on this invention. It is a main part plan view which shows the modification of the heat radiation fin which the heat exchanger which concerns on this invention have. It is a main part plan view which shows the modification of the heat radiation fin which the heat exchanger which concerns on this invention have. It is explanatory drawing for demonstrating the structure of the radiating fin shown in FIG. It is an X-ray image about the cross section of the heat exchanger which concerns on this invention used for the heat transfer characteristic evaluation test. It is an X-ray image about the cross section of the conventional heat exchanger used for the heat transfer characteristic evaluation test. It is a graph which shows the heat transfer property test result performed by the inventor. It is explanatory drawing for demonstrating the radiating fin structure which a conventional heat exchanger has.

Hereinafter, the heat exchanger according to the present invention will be described with reference to the accompanying drawings. Each figure is partially enlarged or reduced to facilitate understanding of the configuration. FIG. 1 is a schematic configuration plan view of the heat exchanger 1 according to the present invention, and FIG. 2 is an enlarged sectional view of a main part of FIG. Further, FIG. 3 is a plan view of a main part of the heat radiation fin 3 included in the heat exchanger 1, and FIG. 4 is an enlarged cross-sectional view of the main part of FIG. As shown in FIGS. 1 and 2, the heat exchanger 1 includes a plurality of heat transfer tubes 2 and a plurality of heat radiation fins 3 arranged at predetermined intervals. The plurality of heat radiation fins 3 are arranged so as to penetrate through the plurality of heat transfer tubes 2.

The heat transfer tube 2 is a pipe-shaped member through which a fluid flows, and is composed of, for example, a stainless steel tube, a copper tube, an aluminum tube, or the like.

The heat radiation fin 3 is formed of a plate-shaped member, and has a fin main body 31, a through hole 32 formed in the fin main body 31, and a joint portion 33 formed so as to project from the peripheral edge of the through hole 32. I have.

As the plate-shaped member forming the heat radiation fin 3, for example, a stainless steel plate or an aluminum plate having a plate thickness of about 0.1 mm to 0.5 mm can be preferably used. The through holes 32 are holes through which the heat transfer tube 2 is penetrated, and a plurality of through holes 32 are formed in the fin main body 31 at predetermined intervals. The through hole 32 is formed as a round hole, and its diameter is formed to be slightly smaller than the outer diameter of the heat transfer tube 2. The joint portion 33 is a member that is externally fitted to the heat transfer tube 2, and is formed so as to project in a direction substantially perpendicular to one surface of the fin main body 31.

Further, as shown in FIGS. 3 and 4, the joint portion 33 is formed in a short cylindrical shape, and the inner diameter of the joint portion 33 is configured to have the same size as the diameter of the through hole 32. .. That is, the inner peripheral surface of the joint portion 33 is formed as a straight surface that slidably fits with the outer peripheral surface of the heat transfer tube 2. More specifically, the inner peripheral surface of the joint portion 33 formed in the shape of a short cylinder has the same dimensions along the axial direction of the joint portion 33 (protrusion direction of the joint portion 33) without changing its diameter. Such a joint portion 33, which is configured to have such a joint portion 33, can be formed together with the through hole 32 by raising and processing the peripheral edge portion (a part of the fin main body 31) of the hole formed in the fin main body 31. can. At the time of start-up processing, the joint portion 33 including the boundary portion between the joint portion 33 and the through hole 32 is provided with a mold or the like so that the short tubular joint portion 33 does not have a tapered shape. Hold the outer peripheral surface side.

Further, as shown in the explanatory view of FIG. 5, the thickness TL of the tip of the joint portion 33 of the one heat radiation fin 3 on the protruding direction side is the fin of another heat radiation fin 3 adjacent to the one heat radiation fin 3. It is configured to be larger than the radius of curvature dimension R at the hole peripheral edge corner of the through hole 32 penetrating on the other surface side of the main body 31. Further, each heat radiation fin 3 is arranged so that the tip of the joint portion 33 of one heat radiation fin 3 abuts on the peripheral edge of the through hole 32 on the other surface side of the fin main body 31 of the other heat radiation fin 3. It is configured.

As described above, in the heat exchanger 1 according to the present invention, the inner peripheral surface of the joint portion 33 provided in the heat radiation fin 3 is configured as a straight surface, so that the entire inner peripheral surface of the joint portion 33 is the surface of the heat transfer tube 2. The heat transfer performance from the heat transfer tube 2 to the heat radiation fin 3 is greatly improved, and high heat exchange efficiency can be exhibited. In particular, by disposing each fin so that the tip of the joint portion 33 of the heat radiation fin 3 abuts on the peripheral edge of the through hole 32 on the other surface side of the fin body 31 of the other heat radiation fin 3, a plurality of heat radiation is dissipated. In a predetermined region on the heat transfer tube 2 where the fins 3 are arranged, the entire outer surface of the heat transfer tube 2 is covered in a state of being in close contact with the joint portion 33, so that heat is transferred from the heat transfer tube 2 to the heat radiation fin 3. Since the movement is performed efficiently, it is possible to exhibit even higher heat exchange efficiency.

Further, by having the joint portion 33 whose inner peripheral surface is a straight surface, it is possible to cover the surface of the heat transfer tube 2 with the joint portion 33 so that it is not exposed. This makes it possible to effectively prevent the surface of the heat transfer tube 2 from being damaged by corrosion such as oxidation. In particular, by disposing each fin so that the tip of the joint portion 33 of the heat radiation fin 3 abuts on the peripheral edge of the through hole 32 on the other surface side of the fin main body 31 of the other heat radiation fin 3, a plurality of heat radiation is dissipated. In a predetermined region on the heat transfer tube 2 where the fins 3 are arranged, the outer surface of the heat transfer tube 2 is effectively blocked from contact with the cooling air, so that a high corrosion prevention effect on the surface of the heat transfer tube 2 can be obtained. It becomes possible.

Further, the thickness TL of the tip of the joint portion 33 of the one radiating fin 3 on the protruding direction side penetrates on the other surface side of the fin body 31 of the other radiating fin 3 adjacent to the one radiating fin 3. By being configured to be larger than the radius of curvature dimension R at the hole peripheral edge corner of the hole 32, the tip of one heat radiation fin 3 on the protruding direction side of the joint portion 33 is adjacent to another heat radiation fin. It is possible to effectively prevent the third from being arranged inside the through hole 32. When the thickness TL of the tip of the joint portion 33 on the protruding direction side is smaller than the radius of curvature dimension R at the hole peripheral edge corner of the through hole 32 penetrating on the other surface side of the fin body 31 of the other heat radiation fin 3, for example. When the heat exchanger 1 is used, the radiating fins 3 are pushed by the gas passing between the radiating fins 3 to move, so that the tip of the joint portion 33 on the protruding direction side is as shown in FIG. , A situation occurs in which the heat radiation fins 3 arranged adjacent to each other are arranged inside the through hole 32. As a result, the distance between the heat radiation fins 3 becomes too narrow, and the gas flow rate passing between the heat radiation fins 3 is reduced, so that the heat exchange efficiency is lowered. Further, since the inner portion of the through hole 32 that overlaps with the tip portion of the joint portion 33 on the protruding direction side does not face the heat transfer tube 2, the heat radiated from the heat transfer tube 2 is directly applied. Since it cannot be received, the heat exchange efficiency will be further reduced. On the other hand, as in the present invention, a through hole through which the tip of the joint portion 33 of one heat radiation fin 3 on the protruding direction side penetrates on the other surface side of the fin body 31 of another adjacent heat radiation fin 3. By configuring the joint portion 33 to be larger than the radius of curvature dimension at the hole peripheral edge corner portion 32, the tip of the joint portion 33 on the protruding direction side is arranged inside the through hole 32 in the heat radiation fin 3 arranged adjacently. It is possible to effectively prevent such a situation from occurring, and it is possible to maintain high heat exchange efficiency.

Further, the thickness TL of the tip of the joint portion 33 of the one radiating fin 3 on the protruding direction side penetrates through the other surface side of the fin body 31 of the other radiating fin 3 adjacent to the one radiating fin 3. In the process of inserting a plurality of heat radiation fins 3 into the heat transfer tube 2 and arranging them at predetermined positions by configuring the holes 32 to be larger than the radius of curvature dimension R at the hole peripheral edge corners, the protrusion direction of the joint portion 33. Since the tip on the side can be brought into contact with the peripheral edge of the through hole 32 on the other side of the fin body 31 of the other adjacent heat radiation fins 3, each heat radiation fin 3 can be easily transferred to the heat transfer tube 2 with high positioning accuracy. It can be placed on top.

Specifically, since the distance between the heat radiation fins 3 is determined by the total dimension of the thickness of the fin main body 31 and the length of the joint portion 33, the tip of the joint portion 33 possessed by one heat radiation fin 3 It is possible to obtain an arrangement state of the heat radiation fins 3 maintained at a predetermined interval only by moving one heat radiation fin 3 until the portion abuts on the peripheral edge of the through hole 32 of the other heat radiation fins 3. Become.

Further, in the case of the joint portion 33 formed in a tapered shape whose diameter is reduced in the projecting direction as in the conventional case, when the heat transfer tube 2 is inserted through the joint portion 33 and the heat radiation fin 3 is installed at a predetermined position. There is a problem that the tip portion of the tapered joint portion 33 scrapes the surface of the heat transfer tube 2 and damages the surface of the heat transfer tube 2. When such scratches occur, the progress of corrosion such as oxidation stops, but in the case of the joint portion 33 whose inner peripheral surface is a straight surface as in the present application, the heat transfer tube 2 is attached to the joint portion 33. It is possible to effectively prevent the surface of the heat transfer tube 2 from being scraped when the heat radiation fins 3 are inserted and installed at predetermined positions.

Specifically, in the case of the conventional joint portion 33 formed in a tapered shape in which the inner peripheral surface is reduced in diameter toward the projecting direction, the portion in contact with the surface of the heat transfer tube 2 is a tapered joint portion. It is the tip portion of 33, and the contact portion between the joint portion 33 and the surface of the heat transfer tube 2 is linear. In such a case, even if the heat radiation fin 3 is slightly tilted when the heat radiation fin 3 is moved through the heat transfer tube 2, the tip portion of the joint portion 33 bites into the surface of the heat transfer tube 2. The joint portion 33 slides on the surface of the heat transfer tube 2, and causes scratches on the surface of the heat transfer tube 2. On the other hand, in the case of the joint portion 33 according to the present invention having a straight surface on the inner surface, since the entire inner peripheral surface of the joint portion 33 is in contact with the surface of the heat transfer tube 2, the heat radiation fin 3 penetrates the heat transfer tube 2. Even if the heat radiation fin 3 is tilted when the heat transfer fin 3 is tilted, the tip portion of the joint portion 33 does not bite into the surface of the heat transfer tube 2, and as a result, a scratch is formed on the surface of the heat transfer tube 2. It is effectively suppressed. In the case of the joint portion 33 according to the present invention having a straight surface on the inner surface, when the joint portion 33 slides on the surface of the heat transfer tube 2, the inner peripheral surface of the joint portion 33 and the heat transfer tube 2 have a wide area. Since the joint portion 33 slides in contact with the heat transfer tube 2, the surface of the heat transfer tube 2 is polished. As a result, a part of the scratches and dirt formed on the surface of the heat transfer tube 2 are removed, which contributes to the improvement of the heat transfer efficiency.

Although the heat exchanger 1 according to the embodiment of the present invention has been described above, the specific configuration of the heat exchanger 1 is not limited to the above embodiment. For example, as shown in the plan view of the main part of FIG. 7, the fin main body 31 may be configured to include the slit 4. Such a slit 4 is preferably formed between the through holes 32. .. By providing the slit 4, the contact surface area between the air supplied to the heat radiation fin 3 and the fin main body 31 is increased, so that the heat exchange efficiency can be further improved. Further, it is possible to effectively prevent the fin body 31 that has received heat from the heat transfer tube 2 from being deformed by so-called heat elongation.

Further, as shown in the enlarged cross-sectional view of the main part of FIG. 8, the protruding piece 5 may be provided at the tip of the joint portion 33 included in the heat radiation fin 3. The protruding piece 5 is formed so as to project radially outward from the opening edge of the tip portion of the joint portion 33. Further, it is preferable that the projecting piece 5 is configured to project in the direction perpendicular to the outer surface of the short cylindrical joint portion 33. Further, the projecting piece 5 has, for example, a ring-shaped form arranged along the opening edge of the tip portion of the joint portion 33, as shown in FIG. 9A showing the AA cross section of FIG. Or, as shown in FIG. 9 (b), it may be in the shape of a tongue piece. Further, the width W (protruding dimension) along the protruding direction of the protruding piece 5 is the radius of curvature dimension R at the hole peripheral edge corner of the through hole 32 penetrating on the other side of the fin main body 31 of the adjacent other heat radiation fins 3. Is configured to be larger than. Note that FIG. 9B shows a configuration in which four protruding pieces 5 formed in the shape of a tongue piece are provided, but the number is not particularly limited.

By configuring to include such a protruding piece 5, it is possible to effectively prevent a part of the joint portion 33 from being arranged inside the through hole 32 of the other heat radiation fins 3 arranged adjacent to the joint portion 33. Can be done. Further, the heat of the liquid flowing down the heat transfer tube 2 can be transferred to the air side supplied to the heat radiation fins 3 even through the projecting piece 5, so that the heat exchange efficiency of the heat exchanger 1 can be improved. Is possible.

Next, the inventors of the present invention actually manufactured the heat exchanger 1 and the conventional heat exchanger according to the present invention, and evaluated the heat transfer characteristics, which will be described below.

First, the heat exchanger 1 and the conventional heat exchanger according to the present invention both include 64 stainless steel tubes (heat transfer tubes) having an outer diameter of 17.3 mm and an inner diameter of 13.3 mm. It is composed of 4 x 16 stainless steel tubes arranged. The distance between the stainless steel pipes (distance between the centers) is 4.24 cm. Further, the heat radiation fin 3 has a rectangular shape in which the size of the fin body 31 is 7.6 cm × 30 cm, the thickness thereof is 0.2 mm, and the through hole 32 through which each stainless steel tube is penetrated and the penetration thereof. It is configured to include a joint portion 33 projecting from the peripheral edge of the hole 32. The number of heat radiation fins 3 is 800, and the stacking interval of each fin body 31 is 3 mm.

Further, the joint portion 33 of the heat radiation fin 3 of the heat exchanger 1 according to the present invention has an outer shape of 17.45 mm, an inner diameter of 17.05 mm, and a length (the length from the boundary of the through hole 32 to the tip portion). S) is configured to be 3 mm. The inner peripheral surface of the joint portion 33 is a straight surface. On the other hand, the joint portion 33 of the heat radiation fin 3 of the conventional heat exchanger is formed in a tapered shape whose diameter decreases in the projecting direction, and has a length (the length from the boundary of the through hole 32 to the tip portion). It is configured so that the diameter is 2.9 mm. Further, the outer diameter at the boundary of the through hole 32 is 17.7 mm, and the outer diameter at the tip portion in the projecting direction is 17.0 mm. The inner diameter at the boundary of the through hole 32 is 17.3 mm, and the inner diameter at the tip portion in the projecting direction is 16.6 mm.

In each heat exchanger 1 as described above, saturated steam having a temperature of 143.7 ° C. (pressure 3.06 kg / cm ² (G)) is circulated in the heat transfer tube 2, and the temperature is 15 between the heat radiation fins 3. The heat transfer characteristics were evaluated by passing air at ° C and measuring the thermal transmissivity. Here, the wind speed of the air that can pass between the radiating fins 3 is changed to 1 m / s, 2 m / s, 3 m / s, 4 m / s, 5 m / s, and 6 m / s, and thermal transmission at each wind speed is performed. The rate was measured. The air passing between the heat radiation fins 3 was supplied by a fan (model number CMF-NO.3-TH-L-OB-D) manufactured by Teral Inc.

Here, X-ray images of the cross section of the heat exchanger 1 according to the present invention actually used in the heat transfer characteristic evaluation test and the conventional heat exchanger are shown in FIGS. 10 and 11, respectively. Both FIGS. 10 and 11 are X-ray images relating to a cross section of a stainless steel tube (heat transfer tube) along the axis. From FIG. 10, in the heat exchanger 1 according to the present invention, the entire inner peripheral surface of the joint formed by projecting from the peripheral edge of the through hole 32 formed in the fin main body 31 is covered with a stainless steel pipe (transmission). It can be seen that it is in close contact with the surface of the heat tube). On the other hand, from FIG. 11, in the conventional heat exchanger, the portion of the joint portion that is substantially in close contact with the surface of the stainless steel tube (heat transfer tube) is a region of about half of the protrusion direction of the joint portion. Things change.

Table 1 shows the thermal flow rate at each wind speed in the heat exchanger 1 according to the present invention and the conventional heat exchanger, and FIG. 12 is a graph in which the horizontal axis is the wind speed and the vertical axis is the thermal flow rate. Is shown. Here, the improvement rate (improvement rate of thermal transmission rate) in Table 1 is calculated by the following formula.
Formula: [(Heat transmission rate in heat exchanger 1 according to the present invention)-(Heat transmission rate in conventional heat exchanger)] / (Heat transmission rate in conventional heat exchanger) × 100 (%)

From this heat transfer characteristic evaluation result, it can be seen that the heat exchanger 1 according to the present invention can improve the heat transfer coefficient by about 15% as compared with the conventional heat exchanger.

As described above, by improving the heat transfer rate, for example, when the heat exchange capacity equivalent to that of the conventional heat exchanger is exhibited, the form can be made more compact than the conventional heat exchanger. Further, as a result of being able to be made compact, the pressure loss of the gas sent to the heat radiation fin 3 can be reduced, so that the fan for sending the gas to the heat radiation fin 3 can be made smaller, and the cost of the heat exchanger 1 itself can be reduced. Can be lowered.

Further, in the case of the heat exchanger 1 having the same size as the conventional heat exchanger, the temperature difference of the gas sent to the heat radiation fins 3 (the temperature of the gas flowing into the heat exchanger 1 and the outflow from the heat exchanger 1). Since it is possible to set the difference from the gas temperature to be larger than that of the conventional heat exchanger, it is possible to improve the heat exchange performance as compared with the conventional heat exchanger.

Further, the inventors have determined the inner diameter of the joint portion 33 (or the inner diameter of the through hole 32) and the outer diameter of the heat transfer tube 2 so that the joint portion 33 and the through hole 32 can be fitted onto the heat transfer tube 2 without being significantly distorted. Now that we have clarified the relationship between, I will explain its contents.

To clarify the relationship between the inner diameter of the joint 33 (or the inner diameter of the through hole 32) and the outer diameter of the heat transfer tube 2 so that the joint 33 and the through hole 32 can be fitted onto the heat transfer tube 2 without being significantly distorted. So, I examined the following models. That is, for the heat radiation fin 3, the thickness of the fin body 31 is t1, the inner diameter of the joint 33 (through hole 32) is d1, the strain in the joint 33 (through hole 32) is ε1, and the heat transfer tube 2 is. Assuming that the wall thickness of the heat transfer tube 2 is t2, the outer diameter of the heat transfer tube 2 is d2, and the strain in the heat transfer tube 2 is ε2, the joint portion after the joint portion 33 (through hole 32) is inserted into the heat transfer tube 2 The diameter D of 33 minutes can be expressed by the following formula A.
Equation A: D = d1 · (1 + ε1) = d2 · (1 + ε2)

Further, since it is considered that the "tensile load acting on the heat radiation fin 3 side" and the "compressive load acting on the heat transfer tube 2 side" are in equilibrium.
"Tension load acting on the heat radiation fin 3 side" = "compressive load acting on the heat transfer tube 2 side", and the Young's modulus of the material forming the fin body 31 is E1, and the Young's modulus of the material forming the heat transfer tube 2 is set. If E2, the following equation B holds.
Equation B: E1, ε1, t1, (representative length L) + E2, ε2, t2, (representative length L) = 0

From the formula A, d2-d1 = d1, ε1-d2, ε2 can be obtained.
From Equation B, d2-d1 = d1 · ε1 + d2 · E1 · ε1 · t1 / (E2 · t2) = ((d1 · E2 · t2 + d2 · E1 · t1) / (E2 · t2)) · ε1 are obtained, and both From the formula
ε1 = E2 ・ t2 ・ (d2-d1) / (E2 ・ d1 ・ t2 + E1 ・ d2 ・ t1)
Is obtained (Equation C).

By substituting the respective values of the thickness t1 of the fin body 31, the inner diameter d1 of the joint portion 33 (through hole 32), the wall thickness t2 of the heat transfer tube 2, and the outer diameter d2 of the heat transfer tube 2 into the above formula C, heat is dissipated. The strain ε1 generated in the fin 3 was calculated. Since the material forming the fin body 31 and the material forming the heat transfer tube 2 are assumed to be the same material, the Young's modulus E1 and E2 are calculated as the same numerical value as the strain ε1.

Table 2 shows a combination of the thickness t1 of the fin body 31 substituted into the above formula C, the inner diameter d1 of the joint portion 33 (through hole 32), the wall thickness t2 of the heat transfer tube 2, and the outer diameter d2 of the heat transfer tube 2. In Table 2, the calculated strain ε1 and the ratio (d1 / d2) of the inner diameter d1 of the joint portion 33 (through hole 32) to the outer diameter d2 of the heat transfer tube 2 are also shown. Further, in the combination B in Table 2, the values of the heat radiation fin t1 and the wall thickness t2 of the heat transfer tube 2 in the combination A are changed, and in the combination C, the value of the wall thickness t1 of the heat radiation fin 3 in the combination A is changed. It will be changed. Further, in combination D, the value of the inner diameter d1 of the heat radiation fin 3 in combination A and the outer diameter d2 of the heat transfer tube 2 are changed, and in combination E, the outer diameter d2 of the heat transfer tube 2 in combination D is changed. It becomes a thing. Further, the combination F is obtained by changing the wall thickness t1 of the heat radiation fin 3 in the combination E.

From Table 2 above, the ratio (d1 / d2) of the inner diameter d1 of the joint portion 33 (through hole 32) to the outer diameter d2 of the heat transfer tube 2 when the strain ε1 is smaller than 0.030 is about 0.970. It can be seen that it is. From this, the ratio of the inner diameter of the joint portion 33 (inner diameter of the through hole 32) before being fitted into the heat transfer tube 2 to the outer diameter of the heat transfer tube 2 is 0.970 or more, more preferably 0.980 or more. By doing so, it is considered that the joint portion 33 and the through hole 32 can be externally fitted to the heat transfer tube 2 without being significantly distorted.

1 Heat exchanger 2 Heat transfer tube 3 Heat dissipation fin 31 Fin body 32 Through hole 33 Joint 4 Slit 5 Protruding piece

The object of the present invention is a heat radiation fin used in a heat exchanger, which is a plate-shaped fin body, a through hole formed in the fin body through which a heat transfer tube included in the heat exchanger penetrates, and the fin. A short-cylindrical joint formed by projecting from the peripheral edge of the through hole on one side of the main body in a direction perpendicular to one surface of the fin main body is provided. The entire area of the inner peripheral surface of the heat transfer tube is configured to have the same dimensions without changing its diameter along the axial direction of the joint portion, and is a straight surface slidably fitted to the outer peripheral surface of the heat transfer tube. Achieved by heat dissipation fins characterized by being formed as.

Claims (3)

A heat dissipation fin used in heat exchangers
A plate-shaped fin body, a through hole formed in the fin body through which a heat transfer tube provided in the finned heat exchanger penetrates, and one surface of the fin body from the peripheral edge of the through hole on one surface side of the fin body. It is equipped with a short cylindrical joint formed so as to project vertically with respect to the above.
The entire area of the inner peripheral surface of the short cylindrical joint portion is configured to have the same dimensions without changing its diameter along the axial direction of the joint portion, and slides on the outer peripheral surface of the heat transfer tube. A radiating fin characterized by being formed as a straight surface that fits nicely. A heat exchanger having a plurality of heat dissipation fins according to claim 1.
A plurality of heat transfer tubes and a plurality of the heat transfer fins arranged at predetermined intervals are provided, and each of the heat transfer fins is arranged so as to penetrate the heat transfer tube through the joint portion. Heat exchanger. The heat exchanger according to claim 2, wherein the ratio of the inner diameter of the joint portion to the outer diameter of the heat transfer tube (inner diameter of the joint portion / outer diameter of the heat transfer tube) is 0.970 or more. ..

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