WO2017168747A1

WO2017168747A1 - Pipe and heat exchanger provided with said pipe

Info

Publication number: WO2017168747A1
Application number: PCT/JP2016/060900
Authority: WO
Inventors: 崇志中島; 祥彦佐竹; 亮平川端
Original assignee: 三菱電機株式会社
Priority date: 2016-04-01
Filing date: 2016-04-01
Publication date: 2017-10-05
Also published as: JPWO2017168747A1; JP6545364B2

Abstract

According to the present invention, a first pipe (1) has: a main pipe section (13); a fitting section (14) into which a second pipe (3) fits; and an enlarged diameter section (15) that has a larger internal cross-sectional area than the internal cross-sectional areas of the main pipe section (13) and the fitting section (14), wherein the fitting section (14) is provided between the main pipe section (13) and the enlarged diameter section (15).

Description

Piping and heat exchanger equipped with the piping

The present invention relates to a pipe joined to a different pipe using brazing material and a heat exchanger provided with the pipe.

In an air conditioner or a cooling device that is a facility for flowing a heat medium such as a refrigerant or water, piping is frequently used as a heat medium path. In many cases, it is not realistic to configure the entire path with a single pipe, but a number of pipes with different specifications such as pipe diameter, pipe thickness, and bending shape are joined to form a single path. Is common. Therefore, various methods have been devised in order to maintain high airtightness at the joints between the pipes.

For example, as a conventional method for joining pipes, there is a joining method in which a brazing material is supplied to a gap between two pipes using a ring-type brazing material and the pipes are brazed together (for example, see Patent Document 1). .

JP 2012-139709 A

However, in the structure described in Patent Document 1, since the brazing material is arranged without being fixed on the pipe, there is a problem that it is displaced from a predetermined position in the brazing process. Moreover, when assembling with the pipes horizontal in the structure described in Patent Document 1, it is difficult to attach the brazing material.

The present invention has been made in view of the above problems, and an object of the present invention is to obtain a pipe capable of easily assembling a pipe when the pipes are joined using a brazing material. .

The pipe according to the present invention has a main pipe part, a fitting part that fits different pipes inside, and a diameter-expanding part that has an inner cross-sectional area larger than the inner cross-sectional area of the main pipe part and the fitting part. The fitting part is provided between the main pipe part and the enlarged diameter part.

Since the pipe according to the present invention has the enlarged diameter portion for storing the brazing material, the brazing material can be arranged at a predetermined position before inserting different pipes, and the pipes can be assembled easily.

It is a figure which shows the heat exchanger which concerns on this invention. It is a figure which shows the 1st piping which concerns on Embodiment 1 of this invention. It is a figure which shows the form of a fin. It is a figure which shows the joining structure of piping before brazing concerning Embodiment 1 of this invention. It is a flowchart explaining the joining process of piping. It is a figure which shows the joining structure of piping after brazing which concerns on Embodiment 1 of this invention. It is a figure which shows the joining structure of piping before brazing concerning Embodiment 2 of this invention. It is a figure which shows the 1st piping which concerns on Embodiment 2 of this invention. It is a figure which shows the 1st piping which concerns on Embodiment 2 of this invention. It is a figure which shows the 1st piping which concerns on Embodiment 2 of this invention. It is a figure which shows the 1st piping which concerns on Embodiment 3 of this invention.

Embodiments of the present invention will be described below with reference to the drawings. In addition, the form of drawing is an example and does not limit this invention. Moreover, what attached | subjected the same code | symbol in each figure is the same, or is equivalent to this, and this is common in the whole text of a specification. Furthermore, the forms of the constituent elements shown in the entire specification are merely examples, and are not limited to these descriptions.

Embodiment 1 FIG.
FIG. 1 is a diagram showing a configuration of a heat exchanger according to the present invention. The heat exchanger 100 includes a first pipe 1, a fin portion 2, a second pipe 3, a U bend 4, and the like. The 1st piping 1 flows heat media, such as water and a refrigerant | coolant, inside, and acts as a heat exchanger tube.

FIG. 2 is a perspective view showing the first pipe 1 according to Embodiment 1 of the present invention. The first pipe 1 is a metal pipe made of an aluminum alloy having a flat shape with a long side portion 1a having a straight section and a short side portion 1b having a curved shape such as a semicircular shape. By making the cross-section flat, the contact area between the heat medium and the heat transfer tube can be increased without increasing the ventilation resistance, and as a result, the performance as a sufficient heat exchanger even when downsized Can be obtained. The first pipe 1 is produced by bending a single straight pipe having flat pipe ports 11 at both ends into a U shape by bending it 180 degrees near the center. Therefore, the first pipe 1 has a bend portion 12.

The fin part 2 includes a plurality of fins 21 arranged in parallel. FIG. 3 is a schematic diagram showing the form of the fins 21. The fin 21 has a plurality of openings 22 into which the first pipe 1 is inserted. The opening 22 has a long side portion 22 a corresponding to the long side portion 1 a of the first pipe 1 and a short side portion 22 b corresponding to the short side portion 1 b of the first pipe 1. A locking portion may be provided around the opening 22 so that the first pipe 1 can be engaged and fixed.

The first pipe 1 is joined to the fin portion 2 composed of a plurality of fins 21 to constitute a heat exchanger core 101. The heat exchanger core 101 is inserted into the plurality of first pipes 1 arranged parallel to the direction orthogonal to the flow direction of the heat medium one by one or a plurality of fins 21 at a time. It is produced by joining. Moreover, you may produce the heat exchanger core 101 by inserting the 1st piping 1 in the several fin 21 arrange | positioned in parallel.

The heat exchanger 100 is configured by inserting the second pipe 3 or the U bend 4 into the plurality of pipe ports 11 of the heat exchanger core 101. The second pipe 3 acts as a pipe for connecting to the outside, and the U bend 4 acts as a pipe for connecting the adjacent first pipes 1. The cross sections of the second pipe 3 and the U bend are flat like the first pipe 1.

FIG. 4 is a cross-sectional view showing a joint structure between pipes before brazing according to Embodiment 1 of the present invention. The first pipe 1 is assembled so that the second pipe 3 is inserted inside the first pipe 1, and the first pipe 1 and the second pipe 3 are joined by brazing. In addition, in FIG. 4, although the joining structure of the 1st piping 1 and the 2nd piping 3 was shown, the joining structure of the 1st piping 1 and U bend 4 is also the same.

The first pipe 1 has a main pipe part 13 for flowing a heat medium therein, a fitting part 14 for fitting the second pipe 3 inside, and a diameter-expanding part 15 for storing the brazing material 30.

The main pipe part 13 acts as a flow path through which a heat medium such as refrigerant or water flows. Further, the main pipe portion 13 is inserted into the opening portion 22 of the fin 21 in order to join the first pipe 1 and the fin portion 2. The fitting portion 14 is provided between the main pipe portion 13 and the diameter-expanded portion 15 and fits the second pipe 3 inserted into the first pipe 1 inside. Therefore, the inner cross-sectional area of the fitting portion 14 is larger than the inner cross-sectional area of the main pipe portion 13. The enlarged diameter portion 15 is provided at the end of the first pipe 1. Inside the enlarged diameter portion 15, a brazing material 30 for joining the first pipe 1 and the second pipe 3 is stored. The inner cross-sectional area of the enlarged diameter portion 15 is formed larger than the inner cross-sectional area of the fitting portion 14.

The brazing material 30 has an action of joining the first pipe 1 and the second pipe 3 by brazing. The brazing material 30 is stored in a space between the enlarged diameter portion 15 and the second pipe 3. Therefore, the brazing filler metal 30 has a ring-shaped shape that is a flat shape similar in cross section to the first pipe 1. Further, the brazing material 30 is formed smaller than the inner diameter of the enlarged diameter portion 15 and larger than the inner diameter of the fitting portion 14 so as to be stored inside the enlarged diameter portion 15. The brazing material 30 is made of an aluminum-silicon type material such as BA4047, which has a lower melting point than aluminum.

Further, a clad layer 31 made of a material having a melting point lower than the melting point of the brazing material 30 may be formed on the inner surface of the first pipe 1. Since the clad layer 31 has a lower melting point, the clad layer 31 is melted before the brazing material 30 when brazing, so that the brazing material 30 is pulled by the clad layer 31. Therefore, it is possible to prevent the brazing material of the brazing material 30 from flowing out of the pipe and causing a brazing failure. The clad layer 31 need not be formed on the entire inner surface of the first pipe 1, but only on a part of the inner surface of the first pipe 1, for example, the inner surfaces of the fitting portion 14 and the enlarged diameter portion 15. May be. The clad layer 31 is made of, for example, a material obtained by adding several percent of zinc to BA40407 used for the brazing material 30.

Next, a method for joining pipes will be described. FIG. 5 is a flowchart for explaining a pipe joining process. First, the heat exchanger core 101 is installed so that the main pipe portion 13 of the first pipe 1 is horizontal (S1). Thereafter, the brazing filler metal 30 is attached to the inside of the enlarged diameter portion 15 of the first pipe 1 (S2). At this time, since the brazing material 30 is attached to the heat exchanger core 101 side before inserting the second pipe 3, workability at the time of pipe assembly can be improved. In addition, since there is no need for parts or configurations for fixing the brazing filler metal 30 at a predetermined position, an increase in manufacturing cost can be suppressed.

Thereafter, the second pipe 3 or the U bend 4 is inserted into the pipe port 11 of the first pipe 1 (S3). The joint structure of the pipes after the second pipe 3 or the U bend 4 is inserted into the first pipe 1 is as shown in FIG.

In order to join the first pipe 1 and the second pipe 3 or the U bend 4 of the heat exchanger 100 assembled in the previous process by brazing, the entire heat exchanger 100 is put into an electric furnace and heated. (S4). The atmosphere in the furnace is filled with an inert gas or a reducing gas. When the temperature of the entire pipe rises, melting of the brazing material begins. Here, by using a material having a melting point lower than that of the brazing material 30 for the cladding layer 31, the cladding layer 31 is melted first. The melt of the clad layer 31 reaches the gap between the first pipe 1 and the second pipe 3 and the surface of the brazing material 30. When the temperature in the furnace further rises, melting of the brazing material 30 is started, and the melt is filled in the gaps between the pipes. Finally, the heating of the electric furnace is terminated and the temperature of the pipe is lowered, so that the melt is solidified and the joining of the first pipe 1 and the second pipe 3 or the U bend 4 is completed (S5). FIG. 6 is a cross-sectional view showing a joint structure between pipes in a state where joining by brazing is completed.

In brazing between pipes made of an aluminum alloy, it is generally necessary to supply flux to the brazing material. As a method of supplying the flux, there are a method of using a flux cored wire in which a flux is contained in the brazing material, a method of applying a flux around the brazing material without including the flux in the brazing material, and the like.

As described above, by providing the enlarged diameter portion 15 for storing the brazing filler metal 30 in the first pipe 1, the brazing filler metal 30 can be disposed at a predetermined position before the second pipe 3 is inserted. The pipes can be assembled together. Furthermore, since the position of the brazing material 30 is less likely to be shifted during the conveying operation in the brazing process, and the brazing material is easily filled in the place where the brazing material should be originally filled, a highly reliable joint can be obtained.

In the present invention, the second pipe 3 is not specially processed. Therefore, since it is not necessary to change the manufacturing process of the second pipe 3, an increase in manufacturing cost can be suppressed.

Embodiment 2. FIG.
FIG. 7 is a cross-sectional view showing a joint structure between pipes before brazing according to Embodiment 2 of the present invention. The second embodiment is different from the first embodiment in that it has a protrusion 16 projecting inwardly at the end of the first pipe 1, but is otherwise the same as the first embodiment.

The protrusion 16 has a shape protruding inward and is formed at the end of the enlarged diameter portion 15 of the first pipe 1. With this configuration, the protrusion 16 has an action of suppressing the brazing material 30 so that the brazing material 30 stored inside the enlarged diameter portion 15 of the first pipe 1 does not shift due to an impact or vibration in an assembly process or a brazing process. .

8 to 10 are perspective views showing the first piping according to Embodiment 2 of the present invention. FIG. 8 shows the first pipe 1 in which the long side portion of the flat-shaped enlarged diameter portion 15 is impacted from the outside, and the protrusion 16 a is formed inside the enlarged diameter portion 15. The protrusion 16a is formed in each of the middle portions of the two long side portions of the enlarged diameter portion 15. By forming the protrusions 16a on the two long side portions, it is possible to prevent the brazing material 30 from falling off due to impact or vibration in the assembly process or the brazing process. Although FIG. 8 shows a configuration in which two protrusions 16a are formed on the long side so as to be symmetrical, the present invention is not limited to this, and one or three or more protrusions 16a are formed at an arbitrary position. You may do it.

FIG. 9 shows the first pipe 1 in which the protrusion 16 b is disposed inside the enlarged diameter portion 15. The first pipe 1 in FIG. 9 is different from the first pipe 1 in FIG. 8 in that a protrusion 16 b is separately provided inside the enlarged diameter portion 15. By disposing the protrusions 16b, it is possible to prevent the brazing material 30 from falling off due to an impact or vibration in an assembly process or a brazing process.

FIG. 10 shows the first pipe 1 in which one protrusion 16c wider than the protrusion 16b of FIG. By forming such a projection 16c, it is easy to attach the brazing material 30 to the first pipe 1, and it is possible to prevent the brazing material 30 from falling off due to impact or vibration in the assembly process or brazing process.

The height of the protrusion 16 is preferably 0.30 mm to 0.60 mm. If it is lower than 0.30 mm, there is a risk that the brazing filler metal 30 will fall off from the enlarged diameter portion 15, and if it is higher than 0.60 mm, it will be difficult to attach the brazing filler metal 30 to the enlarged diameter portion 15.

Although the protrusion 16 has been described with reference to FIGS. 8 to 10, the present invention is not limited to this, and the protrusion 16 prevents the brazing material 30 from falling off from the enlarged diameter portion 15 of the first pipe 1. Any structure or shape that suppresses the brazing material 30 may be used.

Embodiment 3 FIG.
FIG. 11 is a perspective view showing a first pipe according to Embodiment 3 of the present invention. The third embodiment is different from the first embodiment in that the friction portion 17 is provided on the inner surface of the diameter-enlarged portion 15 of the first pipe 1, but is otherwise the same as the first embodiment.

The friction portion 17 is formed on the inner surface of the enlarged diameter portion 15 and has an action of preventing the brazing material 30 from shifting due to friction by contacting the brazing material 30 stored inside. The friction part 17 consists of a plurality of ridges formed along the direction in which the heat medium flows, for example, as shown in FIG.

Further, by forming the inner dimension of the friction portion 17 slightly smaller than the outer diameter of the brazing material 30 that stores the friction part 17 on the inside, it is possible to more effectively prevent the brazing material 30 from falling off or being displaced.

In addition, although illustrated using FIG. 11 as an illustration of the friction part 17, it is not limited to this, The friction part 17 should just be the structure and shape which prevent the brazing | wax material 30 from falling off. For example, the friction part 17 may be formed by making the inner surface of the enlarged diameter part 15 rough.

As mentioned above, although this invention was demonstrated using said each embodiment, the technical scope of this invention is not limited to the range as described in the said embodiment. Various changes or improvements can be added to the above-described embodiments without departing from the gist of the invention, and embodiments to which the changes or improvements are added are also included in the technical scope of the present invention. Moreover, you may combine said each embodiment suitably.

In the present embodiment, each of the first pipe 1, the second pipe 3, the U bend 4, the main pipe part 13, the fitting part 14, and the enlarged diameter part 15 has a flat shape. It is not limited and may be circular or elliptical.

In the present embodiment, the material of the first pipe 1 is an aluminum alloy. However, the material is not limited to this, and may be a material having good thermal conductivity, such as copper or stainless steel.

Further, in the present embodiment, the brazing material 30 has a ring shape that has a flat shape similar to that of the first pipe 1, but the shape of the brazing material 30 is not limited thereto. . The brazing material 30 may be stored inside the enlarged diameter portion 15 of the first pipe 1 and used for joining the pipes by brazing. For example, even if the ring shape is partially cut off good. Moreover, the brazing material 30 may be divided into two or more.

Further, the above-described embodiment is used for an apparatus having a pipe for flowing water or a refrigerant. For example, it can be used for a heat source device having a heat exchanger, an air conditioner equipped with the heat source device, a showcase, a refrigerator, a refrigerator, and the like.

1 1st pipe, 2 fin part, 3rd pipe, 4 U bend, 11 pipe port, 12 bend part, 13 main pipe part, 14 fitting part, 15 enlarged diameter part, 16a protrusion, 16b protrusion, 16c protrusion 17 friction parts, 21 fins, 22 openings, 30 brazing filler metals, 31 clad layers, 100 heat exchangers, 101 heat exchanger cores

Claims

A main section;
A fitting part for fitting different pipes inside,
An enlarged diameter part having an inner cross-sectional area larger than the inner cross-sectional area of the main pipe part and the fitting part,
The fitting portion is a pipe provided between the main pipe portion and the enlarged diameter portion.
The pipe according to claim 1, wherein the enlarged-diameter portion has a protrusion protruding inward.
The pipe according to claim 2, wherein the protrusion is formed at an end of the enlarged diameter portion.
The piping according to claim 1, further comprising a friction part on an inner surface of the enlarged diameter part.
The pipe according to claim 4, wherein the friction part is a ridge formed along a direction in which the heat medium flows.
The pipe according to any one of claims 1 to 5, which has a flat cross section in which a long side portion is a straight line and a short side portion is a curve.
The pipe according to any one of claims 1 to 6, further comprising a clad layer made of a brazing material on an inner surface.
A heat exchanger comprising the pipe according to any one of claims 1 to 7 and a plurality of fins into which the main pipe portion of the pipe is fitted.