JP2002257487A - Spiral fin tube type heat exchanger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inexpensive spiral tube type heat exchanger, coping with both of reduction of a material cost and workability of meandering bending of a heat transfer tube, while contriving the improvement of performance. SOLUTION: The spiral fin tube type heat exchanger 11 is constituted of a refrigerant tube 12, obtained by working a single heat transfer tube so as to have a meandering shape of a straight tube section and a curved tube section connected continuously, and strips 13. Since grooves are provided on the inner surface of the refrigerant tube 12, the reduction of weight of the refrigerant tube 12 can be contrived while contriving the improvement of the performance of the same. A contacting area between the inner wall surface of the refrigerant tube 12 and a mandrel is reduced in the process of meandering bending work of the heat transfer tube whereby a frictional resistance is reduced, the necessity of spraying oil for the lubrication in the tube is eliminated, and the workability of meandering bending of the heat transfer tube can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spiral fin tube type heat exchanger formed by bending a single heat transfer tube used for freezing and refrigeration air conditioning in a meandering manner.

[0002]

2. Description of the Related Art In recent years, heat exchangers used for refrigerators, showcases, and the like have been reduced in size, and in order to prevent performance deterioration due to clogging of the heat exchanger due to dust or the like. Spiral fin tube type heat exchangers which are excellent in space saving and dust resistance are often used.

A conventional spiral fin tube type heat exchanger will be described below with reference to the drawings.

FIG. 7 is a front view of a conventional spiral fin tube type heat exchanger, and FIG. 8 is a sectional view of a conventional spiral fin tube type heat exchanger.

In FIGS. 7 and 8, reference numeral 1 denotes a spiral fin tube type heat exchanger, 2 denotes a refrigerant tube formed by processing a single heat transfer tube into a meandering shape in which a straight tube portion and a curved tube portion are continuous, and 3 denotes a strip plate. It is.

FIG. 9 is a sectional view of a refrigerant tube constituting a conventional spiral fin tube type heat exchanger.

In FIG. 9, reference numeral 4 denotes an inner wall of the refrigerant pipe 2;
A smooth surface is formed, and the wall thickness t1 of the refrigerant pipe 2 is set to 0.1.
4 mm.

The spiral fin tube type heat exchanger 1 includes a refrigerant tube 2 and a band plate 3, and the band plate 3 is spirally wound around the refrigerant tube 2.

The outer diameter of the refrigerant pipe 2 is 4.76 mm, and the bending R of the refrigerant pipe 2 is 16 mm.

When the thickness t1 of the refrigerant tube 2 is 0.4 mm, it is not necessary to insert a metal core into the refrigerant tube 2 in the step of bending the heat transfer tube in a meandering shape, and furthermore, for lubrication. There is no need to spray oil into the pipe.

[0011]

However, since the conventional spiral fin tube type heat exchanger 1 is configured as described above, the thickness t1 of the refrigerant tube 2 is large, that is, the weight per unit length ( (Hereinafter, referred to as single weight) and the material cost was high.

From the viewpoint of material costs, it is preferable to reduce the unit weight of the refrigerant pipe 2.

Therefore, in the conventional spiral fin tube type heat exchanger 1, if the thickness t1 is reduced while the inner wall 4 of the refrigerant tube 2 is kept smooth to reduce the material cost, a core metal is inserted. However, if the heat transfer tube is bent in a meandering shape without spraying oil into the tube for lubrication, the heat transfer tube cannot be bent in a meandering shape because the bent portion is flat or broken.

In this case, in the process of bending the heat transfer tube in a meandering manner, if oil is sprayed into the tube for lubrication, the bending can be performed, but a washing and drying process is required to remove the oil in the tube. Therefore, it is preferable not to spray oil into the pipe for lubrication, since this leads to an increase in the number of manufacturing steps.

That is, in the spiral fin tube type heat exchanger 1, in order to reduce the material cost, the refrigerant pipe 2
When the thickness t1 is reduced while the inner wall 4 is kept smooth, if the core is inserted and the heat transfer tube is bent in a meandering shape without spraying oil into the tube for lubrication, processing becomes impossible. However, there is a problem that the meandering bending workability of the heat transfer tube is reduced.

Further, since the conventional spiral fin tube type heat exchanger 1 is configured as described above, home appliances such as refrigerators have a problem of energy saving. Is indispensable, but there is a problem that there is a limit in extracting the performance of the heat exchanger in a limited space.

The present invention relates to a spiral fin tube type heat exchanger that solves the above-mentioned problems of the prior art, which facilitates high performance while suppressing an increase in size and reduces the unit weight of a refrigerant tube. In addition, it is a low-cost product that improves the meandering bending workability of the heat transfer tube, that is, achieves both high material performance and low heat transfer tube meandering bending workability. It is.

[0018]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, a spiral fin tube type heat exchanger according to the present invention is a refrigerant in which a single heat transfer tube is processed into a meandering shape in which a straight tube portion and a curved tube portion are continuous. In a spiral fin tube type heat exchanger composed of a pipe and a strip wound spirally around the refrigerant pipe, a groove is provided on the inner surface of the refrigerant pipe.

According to the present invention, the provision of the groove in the inner surface of the refrigerant tube facilitates the high performance while suppressing the increase in size, reduces the single weight of the refrigerant tube, and reduces the heat transfer tube. A low-cost spiral fin tube heat exchanger that improves the meandering bending workability, that is, achieves both high performance and reduced material costs and meandering bending properties of heat transfer tubes. Can be provided.

Further, in the present invention, the cross-sectional shape of the groove provided on the inner surface of the refrigerant tube is substantially trapezoidal.

According to the present invention, a low-cost spiral fin tube is provided, in which the material cost is reduced and the meandering bending property of the heat transfer tube is improved while suppressing an increase in size, thereby further improving the performance. A type heat exchanger can be provided.

Further, in the present invention, the developed shape of the groove provided on the inner surface of the refrigerant pipe has angles opposite to each other with respect to the pipe axis in such a manner that the circumference of the pipe is divided by an even number of 4 or more. is there.

According to the present invention, a low-cost spiral fin is provided which reduces material costs and improves the meandering bending workability of the heat transfer tube while suppressing an increase in size, and further dramatically improves the condensation performance. A tube heat exchanger can be provided.

[0024]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the spiral fin tube type heat exchanger of the present invention will be described below with reference to the drawings.

(Embodiment 1) FIG. 1 is a sectional view of a spiral fin tube type heat exchanger according to Embodiment 1 of the present invention.

In FIG. 1, reference numeral 11 denotes a spiral fin tube type heat exchanger, 12 denotes a refrigerant tube formed by processing a single heat transfer tube into a meandering shape in which a straight tube portion and a curved tube portion are continuous, and 13 denotes a band plate.

FIG. 2 is a sectional view of a refrigerant tube constituting the spiral fin tube type heat exchanger, and FIG. 3 is a sectional view of a main part of a refrigerant tube constituting the spiral fin tube type heat exchanger.

In FIGS. 2 and 3, reference numeral 14 denotes an inner wall of the refrigerant pipe 12, and reference numeral 15 denotes a groove.

Spiral fin tube type heat exchanger 11
Is composed of a refrigerant tube 12 and a band plate 13, and the band plate 13 is spirally wound around the refrigerant tube 12.

Here, a groove 15 is provided on the inner surface of the refrigerant pipe 12, and the cross-sectional shape of the groove 15 is substantially triangular.

The pipe outer diameter of the refrigerant pipe 12 is, for example, 3 m
The depth of the groove 15 provided on the inner surface of the refrigerant pipe 12 can be, for example, 0.10 mm to 0.25 mm.

In this embodiment, the outer diameter of the refrigerant pipe 12 is 4.76 mm, and the depth of the groove 15 provided on the inner surface of the refrigerant pipe 12 is 0.15 mm.

The total thickness t2 of the refrigerant pipe 12 is given by t2 = t1 =
In the case of the present embodiment, the unit weight can be reduced by about 25% with respect to the refrigerant pipe 2 used in the conventional spiral fin tube type heat exchanger 1 having a smooth inner surface.

Although the groove 15 provided on the inner surface of the refrigerant pipe 12 has a spiral shape, a similar effect can be obtained even if the groove 15 is linear.

The groove 15 may be rolled or drawn.

The bending R of the refrigerant pipe 12 is 16 mm.

FIG. 4 is a sectional view of a main part of a refrigerant tube in a meandering bending step of the heat transfer tube of the spiral fin tube type heat exchanger.

In FIG. 4, reference numeral 16 denotes a metal core. Refrigerant pipe 1
The contact area between the inner wall 14 and the core 16 is small.

Here, the sample I was the one in which the inner wall surface 14 of the refrigerant pipe 12 was smooth and the thickness t1 was 0.4 mm, and the one in which the inner wall surface 14 of the refrigerant pipe 12 was smooth and the wall thickness t1 was 0.3 mm. A sample II, a groove 15 formed in the inner surface of the refrigerant tube 12 and a total thickness t2 of 0.4 mm as a sample III were subjected to a heat exchange capacity measurement test, and the heat transfer tube was bent in a meandering shape under the same conditions. The results are shown in (Table 1).

[0040]

[Table 1]

First, the sample I and the sample II have the same heat exchange capacity, but the sample III has a 10% improvement over the sample I. This is because, in Sample III, the grooves 15 were provided on the inner surface of the refrigerant tube 12, so that the heat exchange capacity was improved due to the effect of increasing the heat transfer area and promoting turbulence. Thereby, the size of the spiral fin tube type heat exchanger 11 can be reduced.

For the unit weight, III is the refrigerant pipe 1
By providing the groove 15 on the inner surface of Sample No. 2, it is possible to reduce the sample I by 25%.

Further, the sample I is replaced with the sample II,
Although the unit weight reduction rate of III is the same, sample I
In the case of I, since the inner surface of the refrigerant pipe 12 is smooth and the contact area between the inner wall 14 of the refrigerant pipe 12 and the metal core 16 is large, the frictional resistance is large, and it is necessary to spray oil into the pipe for lubrication. III has a groove 15 on the inner surface of the refrigerant tube 12 so that the contact area between the inner surface wall 14 of the refrigerant tube 12 and the core 16 is reduced, so that the frictional resistance is reduced and oil is injected into the tube for lubrication. No need to spray. The spiral fin tube type heat exchanger according to the first embodiment of the present invention configured as described above has the groove 15 provided on the inner surface of the refrigerant tube 12, thereby facilitating high performance while suppressing an increase in size.
The unit weight of the refrigerant pipe 12 can be reduced, and further, in the step of bending the heat transfer pipe in a meandering shape, the inner wall 14
And the contact area between the metal core 16 and the core metal 16 is reduced, so that the frictional resistance is small and there is no need to spray oil for lubrication.
The meandering bendability of the heat transfer tube has been improved.In other words, since the expansion jig is not inserted into the inner surface of the refrigerant tube, the performance of the grooved tube itself having the groove formed on the inner surface of the refrigerant tube is improved. It is possible to achieve both a reduction in material costs and a meandering bending property of the heat transfer tube while improving performance.

(Embodiment 2) FIG. 5 is a sectional view of a main part of a refrigerant tube constituting a spiral fin tube type heat exchanger according to Embodiment 2 of the present invention.

In FIG. 5, 22 is a refrigerant pipe, 24 is an inner wall of the refrigerant pipe 22, and 25 is a groove. Here, the refrigerant pipe 22
Is provided with a groove 25 on the inner surface thereof.

The difference from the first embodiment is that
The cross-sectional shape of the groove 25 provided on the inner surface of the refrigerant pipe 22 is substantially trapezoidal, and this point will be mainly described.

In the above embodiment, since the cross-sectional shape of the groove 25 is substantially trapezoidal, the groove 15 shown in the first embodiment is used.
As compared with the case where the cross-sectional shape is substantially triangular, the reduction of the cross-sectional area of the groove 25 improves the discharge performance of the refrigerant liquid, and further improves the heat transfer coefficient in the tube. Therefore, the heat exchange capacity is further increased.

(Embodiment 3) FIG. 6 is a developed view of a main part of a refrigerant tube constituting a spiral fin tube type heat exchanger according to Embodiment 3 of the present invention.

In FIG. 6, 32 is a refrigerant pipe, 35 is a groove,
37 is a groove intersection.

In this embodiment, grooves having angles opposite to each other with respect to the tube axis are formed on the inner surface of the refrigerant tube so as to divide the circumference into four parts. Here, a groove 35 is formed on the inner surface of the refrigerant pipe 32.
Are formed, and a groove intersection 37 is formed in which grooves having angles opposite to each other with respect to the tube axis intersect.

The difference from the first embodiment is that the developed shape of the groove 35 provided on the inner surface of the refrigerant pipe 32 is opposite to the pipe axis in such a manner that the circumference of the pipe is divided by an even number of 4 or more. This point will be mainly described.

In the above embodiment, the groove 35 is formed in such a manner that the circumference of the pipe is divided by an even number of four or more, and the grooves 35 have angles opposite to each other with respect to the pipe axis. When the refrigerant is condensed in the pipe, the refrigerant collides at the groove intersection 37 and the turbulence is promoted more than when the refrigerant is condensed in the pipe. Dramatically increase. Therefore, the condensation heat exchange capacity is dramatically increased.

The spiral fin tube type heat exchanger is
In order to prevent performance degradation due to dust clogging, it is often used as a condenser installed in the lower part of refrigerators, showcases, etc., and a significant improvement in condensation performance greatly contributes to energy saving.

[0054]

As described above, according to the first aspect of the present invention, there is provided a refrigerant pipe in which a single heat transfer tube is processed into a meandering shape in which a straight pipe portion and a curved pipe portion are continuous, and a spiral pipe formed in the refrigerant tube. In the spiral fin tube type heat exchanger constituted by a band plate wound around the spiral fin tube type heat exchanger, wherein a groove is provided on the inner surface of the refrigerant tube, the groove is formed on the inner surface of the refrigerant tube. With the provision of the above, the high performance is facilitated while suppressing the increase in size, the single weight of the refrigerant tube is reduced, and the meandering bending workability of the heat transfer tube is improved. This has the effect of reducing material costs and improving the meandering bending workability of the heat transfer tube while improving performance.

According to the second aspect of the present invention, the cross-sectional shape of the groove provided on the inner surface of the refrigerant tube is substantially trapezoidal, so that the material cost can be reduced and the heat transfer tube can be reduced while suppressing an increase in size. Has the effect of improving the meandering bending workability and further improving the performance.

According to a third aspect of the present invention, the development shape of the groove provided on the inner surface of the refrigerant pipe is opposite to the pipe axis in such a manner that the circumference of the pipe is divided by an even number of four or more. It has an angle, and has the effect of reducing material costs and improving the meandering bending workability of the heat transfer tube while further suppressing the increase in size, and further dramatically improving the condensation performance.

[Brief description of the drawings]

FIG. 1 is a sectional view of a portion corresponding to FIG. 8 of a spiral fin tube type heat exchanger according to Embodiment 1 of the present invention.

FIG. 2 is a cross-sectional view of a refrigerant tube constituting the spiral fin tube type heat exchanger.

FIG. 3 is a sectional view of a main part of a refrigerant pipe constituting the spiral fin tube type heat exchanger.

FIG. 4 is a sectional view of a main part of a refrigerant tube in a meandering bending process of the heat transfer tube of the spiral fin tube type heat exchanger.

FIG. 5 is a sectional view of a main part of a refrigerant tube constituting a spiral fin tube type heat exchanger according to Embodiment 2 of the present invention.

FIG. 6 is a development view of a main part of a refrigerant tube included in a spiral fin tube type heat exchanger according to Embodiment 3 of the present invention.

FIG. 7 is a front view of a conventional spiral fin tube type heat exchanger.

FIG. 8 is a sectional view taken along line BB ′ of FIG. 7;

FIG. 9 is a sectional view of a refrigerant tube constituting a conventional spiral fin tube type heat exchanger.

[Explanation of symbols]

 11 Spiral fin tube type heat exchanger 12, 22, 32 Refrigerant tube 13 Strip plate 15, 25, 35 Groove

Claims (3)

[The claims] 1. A spiral fin tube type heat exchanger comprising a refrigerant tube formed by processing a single heat transfer tube into a meandering shape in which a straight tube portion and a curved tube portion are continuous, and a band plate spirally wound around the refrigerant tube. A spiral fin tube type heat exchanger, wherein a groove is provided on an inner surface of the refrigerant tube in the exchanger. 2. The cross-sectional shape of the groove provided on the inner surface of the refrigerant pipe is as follows:
The spiral fin tube type heat exchanger according to claim 1, wherein the heat exchanger is substantially trapezoidal. 3. The developed shape of the groove provided on the inner surface of the refrigerant pipe is as follows:
The spiral fin tube type heat exchanger according to claim 1 or 2, wherein the circumference of the tube is inclined with respect to the tube axis in such a manner as to divide the circumference of the tube by an even number of 4 or more, and has angles opposite to each other.