JP2008008585A - Tube for heat exchanger - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a tube for a heat exchanger, which easily sets the optimum interval of communication holes of an inner fin, and favorably fixes a holding part and the inner fin by brazing. <P>SOLUTION: The tube 1 for heat exchangers is provided with: a flat tube like holder part 2; the corrugated inner fin 3 housed in the holder part 2 and forming a plurality of circulation medium passages 4 extending in a longitudinal direction of the holder part 2; and a plurality of communication holes 5 mutually communicated with adjacent circulation medium passages 4 of the inner fin 3 and arranged at a predetermined interval in a longitudinal direction of the inner fin 3. Each communication hole 5 is formed astride at least two crests of the inner fin 3, and it is formed like an obliquely crossing slit with respect to the circulation medium passage 4. In the inner fin 3, when the interval between the communication holes 5 is L mm, a width is W mm, a clad ratio is R%, and a thickness is T mm, a brazing index Z=L×W×R×T/100≥0.77. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a heat exchanger tube.

Conventionally, a flat tubular holder part, a corrugated inner fin that is accommodated in the holder part and forms a plurality of circulation medium paths extending in the length direction of the holder part, and a circulation medium path adjacent to the inner fin And a plurality of communication holes arranged at predetermined intervals in the longitudinal direction of the inner fin, each communication hole spans at least two of the wave fins of the inner fin, The technology of a heat exchanger tube formed into a slanting slit shape is known (see Patent Document 1).
JP 2004-61065 A

However, in the conventional heat exchanger tube, if the interval between the communication holes is reduced, the inner fin is buckled by pressurization of the holder portion when the heat exchanger tube is temporarily assembled, and as a result, a part of the inner fin is There was a problem that a poor brazing occurred due to contact with the holder portion.
In addition, there is a problem in that the flux flow is divided at a large number of locations at the inner fin communication holes and is not sufficiently filled, and a good fillet cannot be formed between the holder and brazed.
On the other hand, if the interval between the communication holes is increased, the effect of the communication hole cannot be expected so much, and there has been a demand to easily set the optimal interval between the communication holes of the inner fin.

  The present invention has been made to solve the above-described problems, and the object of the present invention is to easily set the optimal interval between the communication holes of the inner fin, and to fix the holder portion and the inner fin by brazing well. It is to provide a heat exchanger tube.

  According to a first aspect of the present invention, a flat tubular holder portion, and corrugated inner fins that are accommodated in the holder portion and that form a plurality of flow medium passages extending in the longitudinal direction of the holder portion, A plurality of communication holes communicating with each other of the adjacent distribution medium passages of the inner fins and arranged at predetermined intervals in the longitudinal direction of the inner fins, wherein each of the communication holes is at least a wave top of the inner fin. In the heat exchanger tube formed in a slit shape that crosses the two and is oblique to the flow medium passage, the interval between the communication holes in the inner fin is L (mm), the width is W (mm), and the cladding ratio Is R (%) and the plate thickness (mm) is T, the brazing index Z = L × W × R × T / 100 ≧ 0.77.

  According to the first aspect of the present invention, the flat tubular holder portion and the corrugated plate-like member that is accommodated in the holder portion and that forms a plurality of flow medium passages extending in the longitudinal direction of the holder portion. Inner fins and a plurality of communication holes that communicate with each other between adjacent inner passages of the inner fins and are arranged at predetermined intervals in the longitudinal direction of the inner fins, and each of the communication holes includes a wave of the inner fin. In the heat exchanger tube formed in a slit shape that spans at least two of the top portions and obliquely crosses the flow medium passage, the interval between the communication holes in the inner fin is L (mm), and the width is W (mm) When the cladding rate is R (%) and the plate thickness (mm) is T, the brazing index Z = L × W × R × T / 100 ≧ 0.77, so that the inner fin communication hole is optimal. interval Easily set, the holder portion and the inner fin can be satisfactorily brazed.

  Embodiments of the present invention will be described below with reference to the drawings.

Example 1 will be described below.
1 is a perspective view showing a heat exchanger tube according to a first embodiment of the present invention, FIG. 2 is a cross-sectional view illustrating the inside of the heat exchanger tube according to the first embodiment, and FIG. 3 is a side view of an inner fin (a). FIG. 4 is a plan view (b) and FIG. 4 are diagrams for explaining the manufacture of the heat exchanger tube of the first embodiment.

First, the overall configuration will be described.
As shown in FIGS. 1 and 2, the heat exchanger tube 1 according to the first embodiment includes a flat tubular holder portion 2 and a corrugated inner fin 3 housed in the holder portion 2. Yes.

The holder portion 2 includes a pair of flat portions 2a and 2b that face each other at a predetermined interval, a bent portion 2c that integrally connects one width direction end portions of the both flat portions 2a and 2b, and a pair of flat portions. The joints 2d and 2e are formed in a flat tube shape with joints 2d and 2e formed on the other widthwise end of the parts 2a and 2b, and the joints 2d and 2e are joined in contact with each other. Has been.
In addition, as for each joining part 2d and 2e of the present Example 1, the both ends of the width direction of the holder part 2 are respectively wound inside, and a part of the outer periphery is joined, but it is not this limitation.

  The inner fin 3 is formed in a corrugated shape in which peaks 3a and valleys 3b are alternately arranged, each peak 3a is joined to the inner surface of the flat portion 2a, and each valley 3b is joined to the inner surface of the flat portion 2b, Thereby, a plurality of distribution medium passages 4 extending in the longitudinal direction of the holder portion 2 are formed.

Furthermore, as shown in FIG. 3, the inner fin 3 extends over at least two of the tops of the waves formed by the peaks 3 a and the valleys 3 b, and the longitudinal direction of the inner fin 3 (even in the longitudinal direction of the distribution medium passage 4). A plurality of communication holes 5 formed in a slit shape obliquely intersecting with each other are arranged in a staggered manner in the longitudinal direction of the inner fin 3 at a predetermined interval L described later.
The inclination angle of the communication hole 5 with respect to the flow medium passage 4 is preferably about 40 ° to 60 °.

When the interval between the communication holes 5 in the inner fin 3 is L (mm), the width is W (mm), the cladding rate is R (%), and the plate thickness (mm) is T, the brazing index Z = L The values of L, W, R, and T are set so that × W × R × T / 100 ≧ 0.77.
In the first embodiment, L = 15.00 (mm), W = 25.66 mm, R = 10 (%), and T = 0.06 (mm).

  In addition, the constituent members of the heat exchanger tube 1 are all made of aluminum, and the clad material is provided on the outer circumferential surface of the inner fin 3 at the clad rate R, and the clad material is also disposed on the outer circumferential surface of the holder portion 2. Is provided.

  When manufacturing the heat exchanger tube 1 configured in this way, as shown in FIG. 4, the inner fins 3 are arranged inside the holder portion 2 where the joint portions 2d and 2e are expanded, The joint portions 2d and 2e are overlapped with each other, and the flat portions 2a and 2b are temporarily assembled by pressing the corresponding peaks 3a and valleys 3b of the inner fin 3 respectively.

  Next, a plurality of the above-prepared heat exchanger tubes 1 are prepared, and temporarily assembled together with tube plates, fins, etc. not shown to form the core portion of the heat exchanger, and then transferred to a heating furnace not shown. Then, by heat treatment, the joint portions of the constituent members are integrally brazed and fixed.

  One end of the heat exchanger tube 1 configured in this way is connected to the upstream tank of the heat exchanger (not shown), and the other end is connected to the downstream tank of the heat exchanger (not shown). Connected.

Then, while the flow medium in the upstream tank flows into the downstream tank via the flow medium passage 4 of each heat exchanger tube 1, it is cooled by exchanging heat with the outside air passing through the core portion. .
At this time, the inner fin 3 promotes the heat exchange, and a part of the circulation medium circulates between the circulation medium passages 4 adjacent to each other through the communication holes 5, thereby turbulently circulating the circulation medium and Exchange can be promoted.

Here, in the conventional invention, when the interval between the communication holes is reduced, the inner fin is buckled by the pressurization of the holder portion when the heat exchanger tube is temporarily assembled, and as a result, a part of the inner fin However, there is a problem in that brazing failure occurs due to contact with the holder portion.
In addition, there is a problem in that the flux flow is divided at a large number of locations at the inner fin communication holes and is not sufficiently filled, and a good fillet cannot be formed between the holder and brazed.

Therefore, a plurality of types of heat exchange in which the interval L between the communication holes 5 of the heat exchanger tube having a width W = 25.66 mm, a cladding rate R = 10%, and a plate thickness T = 0.06 mm is gradually increased from 4.00 mm. As a result of preparing test tubes and brazing each, the interval L of the communication holes 5 was 5.00 mm or more, that is, brazing index Z = L × W × R × T / 100 ≧ 0.77 ( To be precise, when Z ≧ 0.7698), the heat exchanger tube can be temporarily assembled without causing buckling of the inner fin 3, and furthermore, the holder part 2 and the inner fin 3 can be satisfactorily brazed and fixed. confirmed.
Furthermore, the same result was obtained when W, R, and T were changed to various values within a range in which the design could be changed as an actual product while increasing or decreasing the value of L.
If L is too large, the number of communication holes 5 formed is reduced and the effect of the communication holes 5 cannot be obtained. Therefore, as an actual product, it is preferable that Z ≦ 8.4.

  Accordingly, when the interval between the communication holes 5 of the inner fin 3 is L (mm), the width is W (mm), the cladding ratio is R (%), and the plate thickness (mm) is T, the brazing index Z = L By setting the interval L of the communication holes 5 so that × W × R × T / 100 ≧ 0.77, the optimal interval of the communication holes 5 of the inner fin 3 can be easily set, and the holder portion 2 and the inner The fin 3 can be brazed and fixed satisfactorily.

  Further, the interval L between the communication holes 5 can be determined in advance, and optimum values for the width W, the cladding ratio R, and the plate thickness T can be examined and dealt with. However, the cladding ratio R is preferably set to a value of 15% or less.

Next, the effect will be described.
As described above, in the heat exchanger tube 1 of the first embodiment, a flat tubular holder portion 2 and a plurality of holder portions 2 accommodated in the holder portion 2 and extending in the longitudinal direction of the holder portion 2. The inner fins 3 in the form of corrugated plates forming the circulation medium passages 4 and the circulation medium passages 4 adjacent to the inner fins 3 communicate with each other, and a plurality of communications are arranged at predetermined intervals in the longitudinal direction of the inner fins 3. In the heat exchanger tube 1 provided with holes 5, each communication hole 5 extending over at least two of the wave tops of the inner fins 3 and obliquely formed with respect to the circulation medium passage 4, Brazing index Z = L × W × where L is the distance between the communication holes 5 in the fin 3, W is the width (mm), R (%) is the cladding ratio, and T is the thickness (mm). R × T / 100 ≧ 0.77 Therefore, the optimal spacing of the communicating hole 5 of the inner fin 3 can be easily set, the holder portion and the inner fin 3 can be satisfactorily brazed.

Although the present embodiment has been described above, the present invention is not limited to the above-described embodiment, and design changes and the like within a scope not departing from the gist of the present invention are included in the present invention.
For example, the communication hole 5 only needs to be formed in a slit shape that extends over at least two of the peaks 3a of the inner fin 3 and obliquely intersects with the distribution medium passage 4. As shown in FIG. You may form the communication hole 10 long in a direction.

It is a perspective view which shows the tube for heat exchangers of Example 1 of this invention. It is sectional drawing explaining the inside of the tube for heat exchangers of the present Example 1. FIG. It is the side view (a) and top view (b) of an inner fin. It is a figure explaining manufacture of the tube for heat exchangers of the present Example 1. FIG. It is a figure explaining the tube for heat exchangers of another Example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Heat exchanger tube 2 Holder part 2a, 2b Flat part 2c Bending part 2d, 2e Joint part 3 Inner fin 3a Mountain 3b Valley 4 Distribution medium channel | path 5 Communication hole

Claims (1)

A flat tubular holder,
A corrugated inner fin that is accommodated in the holder part and forms a plurality of flow medium passages extending in the longitudinal direction of the holder part;
A plurality of communication holes arranged at predetermined intervals in the longitudinal direction of the inner fins, and the communication medium passages adjacent to each other of the inner fins communicate with each other;
Each of the communication holes spans at least two of the tops of the waves of the inner fin, and in the heat exchanger tube formed in a slit shape obliquely with respect to the circulation medium passage,
When the interval between the communication holes in the inner fin is L (mm), the width is W (mm), the cladding rate is R (%), and the plate thickness (mm) is T,
Brazing index Z = L × W × R × T / 100 ≧ 0.77
A heat exchanger tube characterized by the above.

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