JPH09303986A - Method and structure for fitting-in between plate fin for heat-exchanger and pipe - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fit-in structure being a PEL(PIPE EXPANSION-LESS) system heat-exchanger to have a wide contact area between a PEL system heatexchanger and excellent adhesion and the high efficiency of heat transfer. SOLUTION: In fit-in between a plate fin 12 for a heatexchanger and a pipe 10, a fin collar 16 at the peripheral part of the hole of a fin through which the pipe 10 is extended is erected in a direction crossing the body surface of the plate fin 12. The pipe 10 is inserted in a hole (a dog bone type hole or respective independent hole) from a direction in which the fin collar 16 is erected, and titted therein. A diameter (d) of the hole of the plate fin 12 through which the pipe 10 is extended is brought into a relation to be smaller by 0.01-0.20mm than an outside diameter D of a pipe (a serpentine pipe, a U-shaped pipe, or a straight pipe) inserted in the hole of the plate fin 12.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to fitting of plate fins and tubes for heat exchangers that can be used in refrigerators, freezer showcases, evaporators and condensers for air conditioners, and radiators for automobiles. The present invention relates to a joining method and a fitting structure.

[0002]

2. Description of the Related Art Conventionally, plate fins and tubes for heat exchangers used in evaporators, condensers, etc. of refrigerators, freezer showcases, air conditioners, etc. have a diameter d of the hole of the plate fins through which the tubes penetrate. Inserting the tube into the hole of the plate fin from the state of having a relationship larger than the outer diameter D of the tube, and then performing mechanical expansion from the inside of the tube to expand the tube so that the plate fin and the tube are closely fitted. Had been done.

However, recently, for the greatest purpose of improving the production efficiency, reducing the production cost, and keeping the inside of the pipe clean, it is not attempted to improve the degree of adhesion between the plate fin and the pipe by the pipe expanding operation. Completed PEL
A plate fin-tube fitting method based on the (PIPE EXPANSION-LESS) method has been adopted.

Generally, the tube expanding operation is performed by passing the tube expander through the inside of the tube. At this time, since the lubricating oil is used, the inside of the tube is contaminated with the oil. Therefore, it is necessary to clean the inside of the pipe after the pipe expanding operation. If the cleaning is insufficient, if it is used by incorporating it in a refrigerator or the like, it will be mixed in the lubricating oil of the compressor, which will hinder the operation of the compressor. Further, it adheres to the wall of the tube and reduces the heat exchange performance.

FIG. 4 is an explanatory view for explaining a fitting method of the plate fin and the tube by the PEL method, and FIG. 5 is a sectional view taken along the line AA of FIG. In this method, the diameter d of the hole 14 of the plate fin 12 through which the tube 10 penetrates has a relationship that is slightly smaller than the outer diameter D of the tube 10. Plate fin 1
It is inserted into the second hole 14 and fitted.

Insertion / fitting of the tube 10 with respect to the plate fin 12 is performed along the circumference of the hole 14 of the plate fin 12 by 1
The plate fin 1 with the fin collar 16 having a height of about mm
The pipe 10 is inserted into the hole 14 from the side where the fin collar 16 is not erected, and the pipe 10 is fitted into the hole 14.

In the case of this fitting method, the plate fin 12
In order to improve the adhesion between the pipe 10 and the pipe 10, the diameter d of the hole 14
And the outer diameter D of the tube 10, if the diameter d of the hole 14 is made too small, the tube 10 is forcibly inserted into the hole 14 of the plate fin 12 and the fin collar 16, and as shown in FIGS. 6 and 7. In addition, since the plate fin 12 is bent and deformed, the outer diameter D of the tube 10 is inserted by 0.01 to 0.20 (mm) larger than the diameter d of the hole 14 so that the plate fin 12 is inserted and fitted. Becomes If d> D-0.01 (mm), the degree of adhesion between the hole 14 and the tube 10 is poor, and it cannot be used.

The relationship between the diameter d of the hole 14 and the outer diameter D of the tube 10 is that the plate fin 12 having the dog-bone type hole 14 as shown in FIG. 8 or the serpentine-type tube 10 as shown in FIG. 8 is fitted with the U-shaped corners being slightly flattened, the holes 14 and 14 are formed in the plate fins 12 which are independent of each other. Straight tube with squeezed tip 1
It is the same even when 0 is fitted, as shown in FIG.

[0009]

Now, the diameter d of the hole 14 will be described.
With respect to the outer diameter D of the tube 10 is 0.01 to 0.20 (mm)
Due to the large relationship, in the case of the conventional method of inserting and fitting, the contact between the plate fin 12 and the tube 10 is a line contact along the circumference of the tube 10 or 0.5 (mm). It is a narrow strip-shaped contact less than the width.

FIG. 10 shows the line contact and the tube 10
Is inserted, the tip portion of the fin collar 16 is cracked and opened. On the other hand, toward the base of the fin collar 16, the plate fin 1
The part 12a of the main body 2 is pulled to the fin collar 1
It is introduced in 6.

FIG. 11 shows a narrow strip contact, in which the tip of the fin collar 16 is in strip contact with the tube 10. On the other hand, at the base of the fin collar 16, the pipe 1
Part 1 of the body of the plate fin 12 with an insertion force of 0
2a is attracted and placed in the fin collar 16. This root portion exerts a spring effect to tighten the pipe 10. This also applies to the case of FIG. However, in any case, the contact area between the plate fins 12 and the tubes 10 is smaller than that of the conventional tube expansion method, and the heat transfer efficiency is poor.

The present invention has been made in view of such a situation.
An object of the present invention is to provide a heat exchanger of the type that has a large contact area between a plate fin and a tube and has good adhesion and good heat transfer efficiency.

[0013]

In order to achieve the above object, the inventors of the present invention, as a result of diligent trial and error, as described in the claims, have plate fins having a dog-bone type hole for a heat exchanger. And a hairpin-shaped tube (U
Or a serpentine tube, or a straight tube to plate fins with independent holes, the plate penetrating part of the plate fin along the circumference of the hole. A plate fin for a heat exchanger, in which a fin collar is erected in a direction substantially orthogonal to the main surface of the plate fin, and a pipe is inserted into the hole and fitted from the side where the fin collar is erected. It proposes a fitting method with a pipe.

Here, the diameter d of the hole through which the pipe penetrates is preferably smaller than the outer diameter D of the pipe by 0.01 to 0.20 (mm). In the case of the relationship of d + 0.01>D> d (mm), as shown in FIG. 2, only the tip portion of the fin collar 16 forms a line contact or a narrow strip contact along the circumference of the tube 10. This is because the plate fin 12 near the base of the fin collar 16 is slightly bent and deformed in the insertion direction by the insertion force of the tube 10. Also, D> d + 0.20
This is because, in the case of the relationship of (mm), the plate fin 12 is curved and deformed as in the case of FIGS. 6 and 7.

Incidentally, d and D mentioned in the text mean the diameter of the hole and the outer diameter of the pipe, respectively, but strictly speaking, they are the average diameter of the hole and the average outer diameter of the pipe. There are variations within the lot, whether it be the diameter of the hole or the outer diameter of the pipe, and the average diameter of the hole and the average outer diameter of the pipe also change if the lots are different.
According to the experience of the present inventor, the diameter of the hole is 0.
The width shows a variation of 04 (mm), and the outer diameter of the tube shows a variation of 0.02 (mm) within the same lot. Also, the average outer diameter of commercially available tubes is 0.40 depending on the lot.
A variation of about (mm) is shown. Therefore, a jig for making holes in the fins needs several types in order to cope with variations in the average outer diameter of the pipe, and is renewed when worn.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is an explanatory view of a fitting structure of a plate fin and a tube formed by the method according to the present invention. That is, in the fitting structure formed by this method, the hole 14 is formed in the plate fin 12, and the fin collar 16 is provided upright around the hole 14 in a direction substantially orthogonal to the main surface of the plate fin 12. Tube 10 in hole 14
And the portion 12a of the plate fin 12 adjacent to the fin collar 16 is bent to the side opposite to the side where the fin collar 16 is erected.
The fin collar 16 is urged toward the upright side of the tube 10 and is in close contact with the tube 10 in a surface contact state.

The fitting structure of the plate fin and the tube is formed as follows. First, the outer diameter D of the pipe 10 to be inserted and fitted into the hole 14 of the plate fin 12 is measured, and the diameter d of the portion of the hole 14 formed in the plate fin 12 through which the pipe 10 penetrates is determined as the outer diameter D of the pipe 10. From 0.01 to 0.
Determine within a range of 20 mm less. Then, the hole 14 having the determined diameter d is formed in the plate fin 12, and the fin collar 16 is formed around the hole 14 in the portion through which the tube 10 penetrates. The holes 14 and the fin collars 16 may be integrally formed at the same time as the plate fins 12 are formed, or may be formed in the plate fins 12 later. In order to have a length, the pipe 10 is often curved in a U shape in some places to form a serpentine pipe. In such a case, the shape of the hole 14 for inserting the pipe 10 is generally a so-called dockbone type. To

Next, the pipe 1 is inserted into the hole 14 of the plate fin 12.
Insert 0. The tube 10 is inserted into the hole 14 from the side where the fin collar 16 is erected. The portion 12a near the base of the fin collar 16 of the plate fin 12 is slightly bent and deformed in the insertion direction by the insertion force of the tube 10, and the hole 14 is slightly expanded so that the tube 10 is inserted into the hole 14. After the insertion, the deformed portion 12a tries to return in the opposite direction due to the spring effect, whereby the fin collar 1
6 tightens the tube 10 in an attempt to shrink, fin collar 16
The surface closely adheres to the tube 10, and the tube 10 is firmly fitted in the hole 14 of the plate fin 12.

[0019]

【Example】

Example 1 Fin Collar Height 1 Around the Circumference of Plate Fin Holes 1
(Mm), size 6 (cm) × 14 (cm) having 6 dog-bone type holes per sheet, thickness 0.15
(Mm) 40 aluminum fins, the size is 6 (cm) × 18 (cm) with the same fin collar height and 8 dogbone-shaped holes per sheet, and a thickness of 0.
40 sets of 15-mm aluminum fins are alternately arranged, and one set is used, and an aluminum serpentine tube having an average outer diameter of 8.01 mm is used, that is, 5 m.
PEL heat exchanger according to the conventional method and PEL heat exchanger according to the method of the present invention for comparative test using one pair of fins and two serpentine tubes with 40 sheets + 40 sheets = 80 sheets configured at m intervals And the above heat exchangers were produced one by one, and the heat exchangers were incorporated as evaporators in a small refrigeration showcase for comparative tests under the same conditions except for the heat exchanger section.
That is, two frozen showcases for comparison and the present invention were manufactured. Here, the average diameter d of the holes of the plate fins is 7.99 (mm), and the average outer diameter D of the tube is 8.01 (mm).
And When these two refrigeration showcases were operated under the same conditions, the power consumption for one month was as follows: the power consumption of the comparative refrigeration showcase: 88 kWh / month The power consumption of the refrigeration showcase according to the present invention: 80 kWh / month Met.

Example 2 Fin collar height 1 (mm) along the circumference of the fin hole
And, 40 fins made of aluminum with a size of 6 (cm) x 14 (cm) and a thickness of 0.15 (mm) each having 6 dog-bone type holes, and the same fin collar height. Size 6 (cm) x 18 (cm) with 8 dog-bone type holes per sheet, thickness 0.15 (m
m) 40 fins made of aluminum are alternately arranged as one set, and a stainless steel serpentine tube having an average outer diameter of 9.49 (mm) is used, that is, 5 mm.
With 40 sheets + 40 sheets = 80 sheets arranged at intervals, two sets of fins and two serpentine tubes are used, and a conventional PEL heat exchanger for comparison test and P according to the present invention are used.
One set of EL heat exchangers was manufactured, and the heat exchangers were incorporated as evaporators in a small refrigeration showcase for comparative tests of a model different from that of Example 1 under the same conditions except for the heat exchanger section. . That is, two frozen showcases for comparison and the present invention were manufactured. Here, the average diameter d of the holes of the plate fin was 9.41 (mm), and the average outer diameter D of the tube was 9.49 (mm). When these two refrigeration showcases were operated under the same conditions, the power consumption for one month was as follows: the power consumption of the comparative refrigeration showcase 72kWH / month The power consumption of the refrigeration showcase according to the present invention 65kWH / month Met.

Example 3 Fin collar height 1 (mm) along the circumference of the fin hole
And, 40 fins made of aluminum with a size of 6 (cm) x 14 (cm) and a thickness of 0.15 (mm) each having 6 dog-bone type holes, and the same fin collar height. Size 6 (cm) x 18 (cm) with 8 dog-bone type holes per sheet, thickness 0.15 (m
m) 40 fins made of aluminum are alternately arranged as one set, and a copper serpentine pipe having an average outer diameter of 9.53 (mm) is used, that is, 40 fins +40 configured at 5 (mm) intervals. The number of sheets is 80 and two sets of fins and two serpentine tubes are used to fabricate one set of conventional PEL heat exchanger for comparison test and one set of PEL heat exchanger according to the invention. The heat exchanger was incorporated as an evaporator into a small refrigeration showcase for comparative tests of a type different from those of Examples 1 and 2 under the same conditions except for the heat exchanger section. That is, two frozen showcases for comparison and the present invention were manufactured. Here, the average diameter d of the holes of the plate fin is 9.51 (mm), and the average outer diameter D of the tube is 9.51 (mm).
It was set to 53 (mm). When these two refrigeration showcases were operated under the same conditions, the power consumption for one month was as follows: the power consumption of the comparative refrigeration showcase: 69 kWh / month The power consumption of the refrigeration showcase according to the present invention: 61 kWh / month Met.

Example 4 As the tube, an aluminum serpentine tube having an average outer diameter of 8.01 (mm) was used, and the diameter d of the plate fin through which the tube penetrates was 7.76, 7.81, 7.86, 7.9
1, 7.96, 7.98, 8.00, 8.01 and other conditions were the same as in Example 1 and PE of the method of the present invention
An L heat exchanger was manufactured and incorporated in a small-sized refrigeration showcase of the same type as in Example 1 as an evaporator, and it was operated for one month. The power consumption for one month is shown in Fig. 3.

[0023]

As is apparent from the above description, according to the present invention, the production efficiency is high, the production cost is low, and
It can contribute to the production of refrigerators, etc. that have good heat transfer and consume less power.

[Brief description of drawings]

FIG. 1 is an explanatory view of a fitting structure between a hole of a plate fin and a tube formed by a method according to the present invention.

FIG. 2 is an explanatory diagram of a fitting structure of a hole of a plate fin and a tube when the diameter of the hole is too large with respect to the outer diameter of the tube.

FIG. 3 is a graph showing the relationship between the diameter d of the hole of the plate fin and the power consumption.

FIG. 4 is an explanatory diagram for explaining a fitting method of a plate fin hole and a tube by a PEL method.

5 is a cross-sectional view taken along the line AA of FIG.

FIG. 6 is an explanatory diagram of a heat exchanger formed by a PEL method.

7 is a cross-sectional view taken along the line BB of FIG.

FIG. 8 is an explanatory diagram of a serpentine tube.

FIG. 9 is an explanatory diagram of a case where a straight pipe is fitted in a hole of a plate fin.

FIG. 10 is an explanatory diagram of a case where a tube is fitted in a hole of a plate fin in a line contact state.

FIG. 11 is an explanatory diagram of a case where a tube is fitted in a hole of a plate fin in a narrow strip contact state.

[Explanation of symbols]

 10 tube 12 plate fin 12a deformed portion 14 hole 16 fin collar

Claims (11)

[Claims] 1. When fitting a plate fin for a heat exchanger and a pipe, a fin collar around a hole of the plate fin where the pipe penetrates is substantially orthogonal to a main surface of the plate fin. A method of fitting a plate fin for a heat exchanger and a tube, which is installed in a direction in which the fin collar is installed, and inserts the tube into the hole from the side where the fin collar is installed, Of the pipe can be inserted and fitted into the hole without significantly impairing the flatness of the pipe, and within a range where the adhesion between the plate fin and the pipe is good, A fitting method of a plate fin for a heat exchanger and a pipe in which the diameter d of the hole is smaller than the outer diameter D of the pipe. 2. The hole comprises a dogbone type hole,
The fitting method for a plate fin for a heat exchanger and a tube according to claim 1, wherein a hairpin-shaped bent tube (U-shaped tube) is inserted into the hole and fitted. 3. A serpentine tube is inserted into and fitted in the holes of a plurality of plate fins in which one plate fin has one or a plurality of dogbone type holes.
A method for fitting a plate fin and a tube for a heat exchanger according to the description. 4. One or a plurality of independent circular holes in one plate fin, or one or a plurality of holes in a plurality of plate fins having one or more dogbone type holes. The straight pipe or the U-shaped part is bent to a hairpin type in a relationship such that the U-shaped part becomes the rearmost part in the insertion direction (U
The method of fitting a plate fin for a heat exchanger and a tube according to claim 1, wherein the tube-shaped tube is inserted and fitted. 5. The fitting method of a plate fin for a heat exchanger and a pipe according to claim 1, wherein the diameter d of the hole is smaller than the outer diameter D of the pipe by 0.01 to 0.20 (mm). . 6. The method for fitting a plate fin for a heat exchanger to a pipe according to claim 1, wherein the pipe is made of an aluminum material, a stainless steel material, or a copper material. 7. A fitting structure of a plate fin and a tube for a heat exchanger, wherein a hole for inserting the tube is formed in the plate fin, and the hole of the hole is fitted around a portion where the tube is fitted. The fin collar is erected in a direction substantially orthogonal to the main surface of the plate fin, the pipe is fitted in the hole, and the portion of the plate fin adjacent to the fin collar is the fin collar. For a heat exchanger that is biased to the side on which the fin collar is erected while being bent to the side opposite to the side on which the fin collar is erected, and the fin collar is in close contact with the pipe in surface contact. Fitting structure of plate fin and tube. 8. The hole comprises a dogbone type hole,
The fitting structure of a plate fin for a heat exchanger and a tube according to claim 7, wherein a hairpin-shaped bent tube (U-shaped tube) is fitted in the hole. 9. A heat exchanger according to claim 7, wherein one plate fin has one or a plurality of dogbone type holes, and the serpentine tube is fitted in the holes of the plurality of plate fins. Fitting structure of plate fin and tube. 10. One or a plurality of independent circular holes in one plate fin, or one or a plurality of holes in a plurality of plate fins having one or more dogbone type holes. The straight pipe or the U-shaped portion is inserted into the hairpin-shaped bent pipe (U-shaped pipe) so that the U-shaped portion is the rearmost part in the insertion direction. Item 7. A fitting structure of a plate fin for heat exchanger and a tube according to Item 7. 11. The fitting structure of a plate fin for a heat exchanger and a pipe according to claim 7, wherein the pipe is made of an aluminum material, a stainless steel material, or a copper material.