WO2013125625A1

WO2013125625A1 - Heat transfer pipe for fin and tube-type heat exchanger and fin and tube-type heat exchanger using same

Info

Publication number: WO2013125625A1
Application number: PCT/JP2013/054295
Authority: WO
Inventors: 史郎柿山
Original assignee: 住友軽金属工業株式会社
Priority date: 2012-02-24
Filing date: 2013-02-21
Publication date: 2013-08-29
Also published as: JP6415976B2; JPWO2013125625A1; JP2018021756A; KR20140136431A; IN2014CN04862A; CN104145169A

Abstract

To provide a heat transfer pipe for a fin and tube-type heat exchanger with which the heat transfer rate on the coolant side can be effectively improved, and a fin and tube-type heat exchanger using the same. Triangular holes (20) are formed in flat multiple hole pipes (14) made of aluminium or an alloy thereof so as to give a ratio (D/h) in the region of 0.40 to 0.80 where (D) is the hydraulic diameter defined by dividing four times the cross-sectional area of the hole by the sum of the length of the sides of the hole and (h) is the height of the hole; and said flat multiple hole pipes (14) and fins (12) made of aluminium or an alloy thereof are assembled to form a fin and tube-type heat exchanger (10).

Description

Heat transfer tube for fin-and-tube heat exchanger and fin-and-tube heat exchanger using the same

The present invention relates to a heat transfer tube for a fin-and-tube heat exchanger and a fin-and-tube heat exchanger using the same, and more particularly to a fin-and-tube in an air conditioner such as a home air conditioner or a packaged air conditioner. The present invention relates to a heat transfer tube suitably used for a mold heat exchanger and a fin-and-tube heat exchanger using the same.

Conventionally, in addition to air conditioning equipment such as home air conditioners, automotive air conditioners, and packaged air conditioners, refrigerators, heat pump water heaters, and the like have used heat exchangers that operate as evaporators or condensers, among them. In home indoor air conditioners and commercial packaged air conditioners, fin-and-tube heat exchangers having a structure in which fins are assembled to heat transfer tubes are most commonly used.

In recent years, heat exchangers using natural refrigerants with low global warming potential have been developed in place of conventional chlorofluorocarbon refrigerants from the viewpoint of protecting the ozone layer and preventing global warming. However, hot water heaters using refrigerants mainly composed of carbon dioxide gas have attracted attention and have been developed. However, fin-and-tube heat exchangers similar to the above are also used in such heat exchangers. It is used.

By the way, such fin-and-tube heat exchangers are generally assembled using fins (outer surface fins) and heat transfer tubes that have been subjected to predetermined processing, and these fins and heat transfer tubes are in close contact with each other. In the structure, it has been put into practical use. And in the heat exchanger having such a structure, while circulating the refrigerant in the heat transfer tube, by flowing air as a heat exchange fluid along the fins in a direction perpendicular to the heat transfer tube, Heat exchange is performed between the refrigerant and the air.

As one of the heat transfer tubes used in such a fin-and-tube heat exchanger, a flat tube having a structure in which a flat tube interior is divided into a plurality of flow paths by a plurality of partition walls. Hole tubes are known. Moreover, in this flat multi-hole tube, what is usually obtained by porthole extrusion of aluminum or aluminum alloy is used, but as a cross-sectional shape of such a flat multi-hole tube, for example, As disclosed in Japanese Patent Application Laid-Open No. 6-142755 (Patent Document 1), a tube having a rectangular flow path is generally used. Further, in such a flat multi-hole tube, in order to improve heat exchange efficiency, it is effective to increase the surface area of the flow path. Therefore, in Japanese Patent Laid-Open No. 5-222480 (Patent Document 2), a square is used. A method for increasing the surface area by forming a large number of minute irregularities on the inner surface of a hole having a shape has been clarified. By increasing the surface area of the flow path in this way, the contact area between the coolant that can circulate inside the hole and the surface of the hole is increased, and the heat transfer coefficient on the coolant side, that is, the heat between the coolant and the heat transfer tube. By improving the transfer rate, the heat exchange efficiency is improved.

However, when forming a flat multi-hole tube by extrusion molding such as porthole extrusion of aluminum or aluminum alloy, the size of the irregularities formed on the inner surface of the hole cannot be reduced so much, the surface area Cannot be increased sufficiently. In particular, when the flat multi-hole tube is made small for the purpose of downsizing the heat exchanger, the holes formed are also small. The improvement effect was not sufficient.

Further, in FIG. 9 (c) of the above-mentioned Patent Document 1 (Japanese Patent Laid-Open No. 6-142755) and Japanese Patent Laid-Open No. 9-72680 (Patent Document 3), the hole cross-sectional shape of the flat multi-hole tube is a triangular shape. What has been made clear. However, in Patent Document 1, when performing extrusion molding of a multi-hole tube, the extension of the life of the die for multi-hole tube extrusion and the improvement of dimensions and accuracy as a product are merely intended for that purpose, There, only a triangular shape is mentioned as an example of the hole shape of the multi-hole tube manufactured using such a die for multi-hole tube extrusion. Moreover, in patent document 3, while obtaining a predetermined | prescribed thickness and a flat surface by cold rolling or cold compression, tensile strength is improved by work hardening so that appropriate hardness and elasticity can be given. As a structure of a porous flat tube that can obtain such characteristics, it has been clarified that the hole shape is an isosceles triangle.

However, in the flat multi-hole pipes disclosed in Patent Documents 1 and 3, the hole shape of the multi-hole pipe formed by extrusion is simply a triangular shape, In order to improve the hardness and elasticity of the hole tube, the hole shape is merely an isosceles triangle shape. In other words, there has been no investigation of the specific shape of the triangle or the heat transfer coefficient of the heat transfer tube.

JP-A-6-142755 JP-A-5-222480 Japanese Patent Laid-Open No. 9-72680

Here, the present invention has been made in the background of such circumstances, and the problem to be solved is a fin-and-tube type that can effectively improve the heat transfer coefficient on the refrigerant side. A heat exchanger tube for a heat exchanger is provided, and a fin and tube heat exchanger for an air conditioner or the like manufactured using such a heat exchanger tube for a fin and tube heat exchanger is provided. Providing it is also an issue to be solved.

And in the present invention, in order to solve such problems, a heat transfer tube for a fin-and-tube heat exchanger to which a fin made of aluminum or an alloy thereof is assembled is made of aluminum or an alloy thereof. It consists of a multi-hole tube having a flat cross-sectional shape as a whole, and a number of triangular cross-sectional holes extending in the tube axis direction are provided in the multi-hole tube so as to be spaced apart from each other in the width direction and arranged parallel to each other. In addition, the ratio (D / h) of the hydraulic diameter: D defined by dividing four times the cross-sectional area of the hole by the sum of the lengths of the holes is 0 (D / h). The gist of the present invention is a heat transfer tube for a fin-and-tube heat exchanger, characterized in that it is configured to fall within the range of .40 to 0.80.

In addition, in one of desirable aspects of the heat transfer tube for a fin-and-tube heat exchanger according to the present invention, the multiple holes provided in the multi-hole tube each have a cross section of a regular triangle or a right triangle. It has a shape. Furthermore, according to one of the other desirable modes of the heat transfer tube for a fin-and-tube heat exchanger according to the present invention, the multi-hole tube is configured such that the triangular cross-section hole is rotated by 180 °. Are alternately arranged in the width direction.

Also, in the present invention, a fin-and-tube heat exchanger is formed by assembling a fin made of aluminum or an alloy thereof and a multi-hole tube made of aluminum or an alloy thereof and having a generally flat cross-sectional shape. The multi-hole tube is configured in a form in which a large number of triangular cross-sectional holes extending in the tube axis direction are arranged in parallel with each other in the width direction. The ratio (D / h) of hydraulic diameter: D defined by dividing 4 times the sum of the side lengths of the holes and the height of the holes: h (D / h) is in the range of 0.40 to 0.80. The gist of the present invention is also a fin-and-tube heat exchanger that is configured to be inside.

According to one of the desirable embodiments of the fin-and-tube heat exchanger according to the present invention, the fin is a corrugated fin, and the corrugated fin is adjacent to the adjacent multi-hole tube. The corrugated fins and the multi-hole tube are assembled so as to be in close contact with each other.

Furthermore, in another desirable aspect of the fin-and-tube heat exchanger according to the present invention, the fin is a flat plate-shaped fin, and is disposed at one end in the width direction of the plate-shaped fin. The multi-hole tube is closely inserted into the slit-shaped assembly hole provided so as to be opened and assembled.

Furthermore, in one of the preferred embodiments of the fin-and-tube heat exchanger according to the present invention, the multiple holes provided in the multi-hole tube each have a cross-sectional shape of a regular triangle or a right triangle. Have. In addition, according to one of the other preferable embodiments of the fin-and-tube heat exchanger according to the present invention, the triangular cross-sectional shape of the hole having the triangular cross section is rotated by 180 °. It will be alternately arranged in the width direction.

Therefore, in such a heat exchanger tube for a fin-and-tube heat exchanger configured according to the present invention, a hole having a triangular cross-sectional shape has a length of the side of the hole that is four times the cross-sectional area. Since the ratio (D / h) of the hydraulic diameter defined by dividing by the sum: D and the height of the hole: h (D / h) is set to an appropriate range, When the refrigerant flows, the area of the inner surface of the multi-hole tube that contacts the unit volume of the refrigerant increases by circulating the refrigerant through the small angle part sandwiched between the two sides of the hole having a triangular cross-sectional shape. Thus, it is possible to effectively improve the heat transfer coefficient between the refrigerant and the heat transfer tube, that is, the heat exchange efficiency of the heat transfer tube. Moreover, since the refrigerant can cause a local flow state by passing through the portion where the angle of such a triangular hole is small, in other words, the portion where the hole is narrow, the heat exchange efficiency is more effective. It becomes possible to raise.

In the fin-and-tube heat exchanger manufactured using the heat transfer tube for the fin-and-tube heat exchanger configured as described above, the heat transfer coefficient on the refrigerant side in the heat-transfer tube is From the point of being advantageously improved, the high heat exchange performance is exhibited, and the effects such as downsizing and weight reduction of the heat exchanger and reduction of the manufacturing cost are advantageously exhibited.

It is a perspective explanatory view showing an example of a fin and tube type heat exchanger according to the present invention. It is a perspective explanatory view which shows the fin which comprises the fin and tube type heat exchanger shown by FIG. It is a cross-sectional explanatory drawing which expands and shows a part of cross section of the flat multi-hole pipe which comprises the fin and tube type heat exchanger shown by FIG. It is front explanatory drawing which shows schematically the fin and tube type heat exchanger for heat exchange performance evaluation used in the Example. It is explanatory drawing which shows the cross section of the flat multi-hole tube according to this invention prepared in order to comprise the heat exchanger used in the Example, Comprising: (a) is a thing whose hole shape is an equilateral triangle shape, (B) shows a hole having a right triangle shape, and (c) shows a right triangle shape having a dimension different from that of (b). It is explanatory drawing which shows the cross section of the flat multi-hole tube prepared in order to comprise the heat exchanger used for the comparison in the Example, (a) is a rectangular shape, (b) is Each of the circular shapes is shown. It is explanatory drawing which expands and shows a part of cross section of the flat multi-hole tube further prepared in order to comprise the heat exchanger used for the comparison in the Example, (a) And (b) , Holes having different triangular cross-sectional shapes are shown.

Hereinafter, in order to clarify the present invention more specifically, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a perspective view schematically showing one embodiment of a fin-and-tube heat exchanger using a heat-transfer tube for a fin-and-tube heat exchanger according to the present invention. Has been. In the heat exchanger 10, two flat

multi-hole tubes

14 and 14 are slits provided in the fins 12 with respect to the plurality of fins 12 arranged in parallel to each other and at a predetermined distance. It is configured by being inserted into the assembly hole 16 and fixed in a form in close contact with the inner surface of the hole.

More specifically, the fins 12 are formed of a metal plate made of aluminum or an aluminum alloy, as in the prior art, and as shown in FIG. It is a plate-like fin. Further, in the fin 12, an assembly hole 16 into which the flat multi-hole tube 14 is assembled extends from one end of the rectangular fin 12 by a predetermined length in the width direction of the fin 12 (left and right direction in FIG. 2). It is formed as a slit having a predetermined width. Further, a collar portion 18 having a predetermined height is formed integrally with the fin 12 around the assembly hole 16 and has a U shape.

On the other hand, as is well known, the flat multi-hole tube 14 is formed of a metal material made of aluminum or aluminum alloy, and here, ten holes 20 extending in the tube axis direction are independently formed. This is a multi-hole tube having a flat shape. Here, the hole 20 has a triangular cross-sectional shape as shown in FIG. 3 in which a part of the cross section in the direction perpendicular to the tube axis is enlarged. It is the same equilateral triangle shape. And as shown in the figure, the adjacent holes 20 of the holes 20 having such a shape are arranged in an inverted manner, in other words, rotated 180 ° alternately. The flat multi-hole tubes 14 are arranged in parallel to each other at a predetermined interval in the width direction.

Further, in such a hole 20, the hydraulic diameter: D defined by dividing four times the cross-sectional area by the sum of the lengths of the sides of the hole, and the height of the hole (the thickness of the multi-hole tube) (Height in the vertical direction): The ratio (D / h) to h is configured to be in the range of 0.40 to 0.80. That is, here, since the hole 20 has a regular triangular shape, D / h = 0.666... ≈0.67, which is configured to be within the above range.

Thus, by setting the shape of the hole 20 so that the ratio of the hydraulic diameter: D and the height of the hole: h is a value within the above range, a portion having a small angle of the hole 20 is obtained. The refrigerant effectively passes, the area of the hole inner surface that contacts per unit volume of the refrigerant is increased, and the heat transfer coefficient between the refrigerant and the heat transfer tube is advantageously improved. Moreover, since a local fluid state generate | occur | produces when a refrigerant | coolant passes through such a small angle part, it also becomes possible to raise a heat transfer rate more effectively. When the value of D / h is smaller than 0.40, the hole 20 becomes too small and it becomes difficult to manufacture, so it becomes impractical. On the other hand, when the value of D / h is larger than 0.80, the contact area per unit volume of the refrigerant is not increased sufficiently, and the effect of improving the heat transfer coefficient is hardly exhibited.

Then, using such flat multi-hole tube 14 and fins 12, a plurality of such fins 12 are separated from each other in parallel and at a constant distance in a state where the assembly holes 16 formed in each of them are aligned. The flat multi-hole tube 14 is fitted into the aligned assembly hole 16 and assembled so that the flat multi-hole tube 14 is in close contact with the inner surface of the assembly hole 16 directly or indirectly. Thus, the target fin-and-tube heat exchanger 10 is configured. As is well known, the flat multi-hole tube 14 and the fins 12 are assembled by various known methods such as assembly by press-fitting or close fitting, joining by brazing, or fixing by an adhesive. Is completed as an integral fin and tube heat exchanger. Further, both end portions of the flat multi-hole tube 14 which is a heat transfer tube constituting such a fin-and-tube heat exchanger are respectively connected to a header (not shown), and the flat multi-hole tube 14 10 The ten holes 20, that is, the ten flow paths through which the refrigerant extending in the tube axis direction is circulated are combined on the refrigerant inlet side and the outlet side to form the fin-and-tube heat exchanger 10. It is.

Accordingly, in the fin-and-tube heat exchanger 10 configured according to the present invention, the shape of the hole 20 formed in the flat multi-hole tube 14 is simply the contact between the refrigerant and the inner surface of the hole. The flat multi-hole tube 14 has a triangular shape that not only increases the area but also increases the contact area per unit volume of the refrigerant to advantageously improve the heat transfer coefficient on the refrigerant side. In this case, the heat exchange efficiency between the refrigerant circulating in the pipe and the heat transfer pipe is effectively improved, and as a result, the heat exchange performance of the heat exchanger 10 can be advantageously enhanced. In addition, by using the flat multi-hole tube 14 that exhibits such a high heat transfer rate, the heat exchanger 10 can be reduced in size and weight, and the effect of reducing the manufacturing cost can be advantageously exhibited. .

As described above, one of the representative embodiments of the present invention has been described in detail. However, this is merely an example, and the present invention is not limited by the specific description according to such an embodiment. It should be understood that this is not to be construed as limiting.

For example, in the above-described embodiment, the fin-and-tube heat exchanger 10 is illustrated in which the flat multi-hole tube 14 is assembled in the assembly hole 16 provided in the plate-like fin 12. For example, as shown in FIG. 4, a corrugated fin type fin-and-tube heat exchanger 30 constructed by assembling corrugated (corrugated) fins 24 between flat

multi-hole tubes

22, 22. It is also possible.

In addition, the shape of the hole 20 formed in the flat multi-hole tube 14 is an equilateral triangle shape in the above embodiment, but the ratio of hydraulic diameter: D and hole height: h (D / If h) is a triangular shape within a predetermined range, various triangular shapes such as a right triangle and an isosceles triangle are appropriately selected. Further, even in the side connecting the three vertices of the triangular shape, as long as D / h satisfies the above-described relationship, in addition to those connecting the vertices in a straight line like the regular equilateral triangle shape, a predetermined value is obtained. It is also possible to use arcuate sides with a radius of curvature.

In addition, the inner surface of the hole 20 is a flat surface here, but may be a surface on which minute irregularities (grooves and ridges) are formed. By forming such irregularities, the contact area between the refrigerant per unit volume and the surface of the hole 20 can be further increased, and the heat transfer coefficient between the refrigerant and the heat transfer tube can be improved more effectively. Become.

In addition, although not listed one by one, the present invention is implemented in a mode to which various changes, modifications, improvements and the like are added based on the knowledge of those skilled in the art. It goes without saying that any one of them falls within the scope of the present invention without departing from the spirit of the invention.

Hereinafter, one representative embodiment of the present invention will be shown to clarify the present invention more specifically. However, the present invention is not limited by the description of such embodiment. It goes without saying that it is not something to receive.

First, as a heat transfer tube for a fin-and-tube heat exchanger according to the present invention, an aluminum alloy (JIS A3003) is extruded to exhibit a cross-sectional shape as shown in FIG. : Extruded flat multi-hole tube 40 having a thickness of 16 mm, a thickness (H) of 1 mm, and a number of holes of 16 was prepared. It was set to 1. Such heat transfer tube No. The shape of the 16 holes (42) provided in 1 was an equilateral triangle having a side length of 0.7 mm. Other specifications such as hole height and hydraulic diameter were as shown in Table 1 below. In Table 1 below, the hole height (h) is the hole height in the thickness direction of the flat multi-hole tube (40), and the channel area is the cross-sectional area of the hole portion in the cross section perpendicular to the axial direction. The wet edge length indicates the sum of the lengths of the sides of the holes in the cross section.

Further, as another example of the heat transfer tube for the fin-and-tube heat exchanger according to the present invention, flat

multi-hole tubes

44 and 46 having a cross-sectional shape as shown in FIGS. 5 (b) and 5 (c), Heat transfer tube no. 1 were prepared in the same manner as in No. 1, respectively. 2. Heat transfer tube no. It was set to 3. Here, heat transfer tube no. No. 2 is a flat multi-hole tube having 16 holes formed in a right triangle having a base of 0.40 mm and a height of 0.50 mm. 3 was a flat multi-hole tube in which 16 holes each having a right triangle with a base of 0.800 mm and a height of 0.500 mm were formed. The heat transfer tube No. As is apparent from the figure, the hole shapes in each of 2 and 3 are configured such that the holes are alternately rotated by 180 °. Also, the heat transfer tube No. The width and thickness of 2 and 3 are the same as the heat transfer tube no. No. 1 and heat transfer tube No. 1 was produced by extruding an aluminum alloy (JIS A3003). Further, these heat transfer tubes No. The specifications such as the channel area and hydraulic diameter in 2 and 3 are as shown in Table 1 below.

As a heat transfer tube for comparison, as shown in FIG. 6A, a flat multi-hole tube 50 having a square hole shape (a length of one side: a square of 0.46 mm), and FIG. 6B. And a flat multi-hole tube 52 having a circular hole shape (a circle having a diameter of 0.52 mm) as shown in FIG. 4. Heat transfer tube no. It was set to 5. Furthermore, although the hole shape is a triangle shape, the D / h value is out of the scope of the present invention, and the hole shape is a right triangle as shown in FIGS. 7 (a) and 7 (b). Flat

multi-hole tubes

54 and 56 were prepared. 6. Heat transfer tube no. It was set to 7. Here, heat transfer tube no. The hole shape of No. 6 is a right triangle (apex angle: 82.9 °) having a base of 4.01 mm and a height of 0.5 mm. The hole shape of No. 7 was a right triangle (apex angle: 72.2 °) having a base of 2.49 mm and a height of 0.8 mm. In addition, those heat exchanger tubes No. As for 4 to 7, heat transfer tube no. As in 1-3, the aluminum alloy (JIS A3003) was produced by extrusion, and the width (W) and thickness (H) were all the same for the heat transfer tube no. The same value as 1. However, in the number of holes, heat transfer tube No. 4 and heat transfer tube no. 5 is 16, heat transfer tube no. 6 is 4, heat transfer tube No. Seven was eight. In addition, those heat exchanger tubes No. The various specifications such as the hole height (h) in 4 to 7 are as shown in Table 1 below.

Next, using each of the flat multi-hole tubes (heat transfer tubes No. 1 to 7) prepared in this way, a plurality of flat multi-hole tubes (22) are arranged in parallel to each other as shown in FIG. The heat exchanger (30) in which the corrugated fins (24) are intimately joined between the adjacent flat multi-hole tubes (22, 22) is referred to as a heat exchanger no. 1 to 7 were produced. In these heat exchangers (30), both ends of the arranged flat multi-hole tubes (22) are respectively connected to the header (26), and the respective holes (in the axial direction of the flat multi-hole tubes (22) ( Are formed on the refrigerant inlet side and the outlet side to form a refrigerant flow path. Moreover, in each heat exchanger (30) manufactured here, the fins (24) are all corrugated with a double-sided brazing sheet using JIS A3703 series as the core material and JIS A4045 series as the skin material. Using the processed material, it was configured to be formed at the same time as joining with the flat multi-hole tube, and 75 flat multi-hole tubes (24) were used in producing one heat exchanger. Such a fin (24) and flat multi-hole tube (22) are joined between a corrugated brazing sheet assembled in the shape of the target heat exchanger (30) and the flat multi-hole tube (22). The assembly is heated and held in a brazing furnace at a maximum temperature of 600 ° C. for 3 minutes, and then cooled, whereby the fin (24) and the flat multi-hole tube (22) are brazed and joined. It was made to be. The length of the flat multi-hole tube (22) between the headers (26, 26) is 610 mm, and the overall size of the heat exchanger (30) is width: 650 mm and height: 610 mm. I did it.

After that, heat exchanger no. A single unit performance evaluation test of each heat exchanger was performed using 1-7. In the test method, each heat exchanger is installed in a wind tunnel device provided in a constant temperature and humidity test chamber, and the air temperature in the test chamber (dry bulb: 35 ° C., wet bulb: 24 ° C.), wind speed (1.5 m / s), the refrigerant (R-410A) is subjected to the following conditions: heat exchanger inlet temperature: 64 ° C. (SH = 20K), condensing temperature: 44 ° C., heat exchanger outlet temperature: 39 ° C. (SC = 5K) The amount of heat exchange in a state where the heat balance between air and refrigerant was set was measured. The test results for each heat exchanger are shown in Table 2 below. In addition, the test result shown in this Table 2 shows heat exchanger No.2 whose hole shape of a flat multi-hole pipe is a square. It is shown using a relative ratio with respect to the case where the heat exchange amount of 4 is 100.

Based on the above results, heat exchangers No. 1 having the same flow path area but different hole shapes formed in each flat multi-hole tube. 1, 4, and 5, the heat exchanger No. 1 having a triangular hole shape according to the present invention. No. 1 is a heat exchanger No. 1 having a square hole shape. 4 or circular heat exchanger No. 4 It was confirmed that the condensation performance was greatly improved than 5. Moreover, the hole shape is a triangle shape, and the ratio of hydraulic diameter: D and hole height: h: D / h is configured using flat

multi-hole tubes

40, 44, 46 within the scope of the present invention. Each heat exchanger No. 1, heat exchanger no. 2 and heat exchanger no. 3 is a heat exchanger No. 3 in which the hole shape of the flat multi-hole tube is a general square. It was confirmed that the heat exchange performance was improved by 1.5% or more than 4. On the other hand, although the hole shape is triangular, the heat exchanger No. D / h is outside the scope of the present invention. 6 and 7, heat exchanger no. Although the performance is better than 4, the performance improvement is less than 0.5%, and the effect of improving the heat transfer coefficient on the refrigerant side in the flat multi-hole tube by making the hole shape triangular is fully demonstrated It was confirmed that it was not.

DESCRIPTION OF SYMBOLS 10 Heat exchanger 12 Fin 14 Flat multi-hole pipe 16 Assembly hole 18 Collar part 20 Hole

Claims

A heat transfer tube for a fin-and-tube heat exchanger to which fins made of aluminum or its alloy are assembled,
A multi-hole tube made of aluminum or an alloy thereof having a flat cross-sectional shape as a whole, and a plurality of triangular cross-sectional holes extending in the tube axis direction are parallel to each other in the width direction. The ratio of hydraulic diameter: D and the height of the hole: h defined by dividing four times the cross-sectional area of the hole by the sum of the lengths of the sides of the hole. A heat transfer tube for a fin-and-tube heat exchanger, characterized in that (D / h) is in the range of 0.40 to 0.80.
The heat transfer tube for a fin-and-tube heat exchanger according to claim 1, wherein a plurality of holes provided in the multi-hole tube each have a cross-sectional shape of a regular triangle or a right triangle.
The fin-and-tube heat according to claim 1 or 2, wherein the holes having a triangular cross-sectional shape are alternately arranged in a width direction of the multi-hole tube in a form in which the holes are rotated by 180 °. Heat exchanger tube for exchanger.
A fin-and-tube heat exchanger in which fins made of aluminum or an alloy thereof and a multi-hole tube made of aluminum or an alloy thereof and having a flat cross-sectional shape as a whole are assembled,
The multi-hole tube is configured in a form in which a large number of triangular cross-sectional holes extending in the tube axis direction are arranged in parallel with each other in the width direction, and four times the cross-sectional area of the holes. Is divided by the sum of the lengths of the sides of the hole, the ratio of hydraulic diameter: D to the height of the hole: h (D / h) is in the range of 0.40 to 0.80. It is comprised so that it may become. The fin and tube type heat exchanger characterized by the above-mentioned.
The corrugated fin is a corrugated fin, the corrugated fin is disposed between the adjacent multi-hole tubes, and the corrugated fin and the multi-hole tube are assembled so as to be in close contact with each other. 4. A fin-and-tube heat exchanger according to 4.
The fin is a flat plate-like fin, and the multi-hole tube is closely inserted into a slit-like assembly hole provided so as to open at one end in the width direction of the plate-like fin. The fin-and-tube heat exchanger according to claim 4, which is assembled.
The fin-and-tube type heat according to any one of claims 4 to 6, wherein a plurality of holes provided in the multi-hole tube each have a cross-sectional shape of an equilateral triangle or a right triangle. Exchanger.
The fin according to any one of claims 4 to 7, wherein the holes having a triangular cross-sectional shape are alternately arranged in a width direction of the multi-hole tube in a form in which the holes are rotated by 180 °. And tube type heat exchanger.