JPS63259395A - Finned-tube type heat exchanger - Google Patents

Abstract

PURPOSE:To improve the heat exchanging performance by inserting both ends of a U-bend into heat transmission pipes to a position that overlaps some fins. CONSTITUTION:At the time of connecting a U-bend 14 to heat transmission pipes 13, the ends of the U-bend 14 are contracted to allow their insertion into the heat transmission pipes 13. The ends of the U-bend 14 are inserted deeper than the end plate 15, i.e. up to a position that overlaps the fin 12. By impregnating the brazing material 16 to the ends of the U-bend 14 at the time of brazing, the pressure resistance strength of the part of the heat transmission pipes 13 extending beyond the end plate 15 can be made larger. As a result, a water pressure high enough can be applied to a heat exchanger having a curved finned- tube, and the curved part of the heat transmission pipes 13 can be made tightly in contact with the fins 12, which improves the heat exchanging performance.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a fin-tube heat exchanger used in refrigeration and air conditioning equipment.

Conventional technology In recent years, fin-tube heat exchangers have been used in a variety of fields in the refrigeration and air-conditioning industries, and in response to the demand for more compact products, the entire fin-tube heat exchanger has been shaped into an abbreviated or U-shaped design. Curved shapes are often used.

An example of the conventional fin-tube heat exchanger mentioned above will be described below with reference to the drawings.

FIG. 2 shows a conventional fin-tube heat exchanger. FIG. 3 is a partial cross-sectional view of FIG. 2.

In the figure, 1 is a curved fin-tube heat exchanger. 2 is a group of fins arranged in large numbers at regular intervals, through which air flows; 3 is a heat exchanger tube through which fluid flows; 4;
is brazed to the heat exchanger tube 3, and the direction of fluid flow is 1800 degrees.
It is a substantially U-shaped bend to be converted, and its wall thickness is thicker than that of the heat exchanger tube 3. 6 is an end plate arranged at both ends of the fin group 2;
6 is a brazing material that joins the heat exchanger tube 3 and the substantially U-shaped bend 4.

As shown in FIG. 2, in a fin-tube heat exchanger whose main components are a fin group 2 and a heat exchanger tube 3.

As a method of bringing the fin group 2 and the heat transfer tubes 3 into close contact, there is a hydraulic tube expansion method. In the hydraulic pipe expansion method, a heat transfer tube 3 bent into a U-shape is inserted into holes drilled in the fin group 2 and an end plate 6, and an iU-shaped bend is brazed to the open end of the heat transfer tube 3. By applying water pressure inside the heat exchanger tube 3 and the substantially U-shaped bend, the heat exchanger tube 3 is expanded and brought into close contact with the fin group 2. In a curved fin-tube heat exchanger as shown in Fig. 2, bending is performed before hydraulic expansion, so the curved portion of the heat transfer tube 3 undergoes work hardening during bending, and compared to before bending. The pipe cannot be expanded unless the water pressure is higher. Therefore, compared to a straight heat exchanger, a curved fin tube type heat exchanger requires higher water pressure to be applied in order to bring the entire heat exchanger tube 3 into close contact with the fins.

However, as shown in FIG. 3, the conventional method of connecting the approximately U-shaped bend 4 to the heat exchanger tube 3 is to further expand the end of the heat exchanger tube 3 and insert the heat exchanger tube 3 into that portion (secondary expanded portion). A substantially U-shaped bend 4 having the same outer diameter is inserted and brazed.

Problems to be Solved by the Invention However, in the above configuration, the approximately U-shaped bend 4
Brazing is sometimes done not only on the approximately U-shaped bend 4 but also on the heat exchanger tube 3.
is also heated, and the tensile strength of the material decreases. For this reason, after bending the fin-tube heat exchanger 1, it is brazed and expanded using hydraulic pressure. However, since the approximately U-shaped bend 4 is thicker, the secondary expansion portion of the thinner heat exchanger tube 3 is performed. and the end plate 5 will rupture. For this reason, the pipe cannot be expanded by sufficiently increasing the water pressure, and there is a problem in that the heat exchanger tubes 3 and the fin group 2 are not in close contact with each other at the curved portions, and the heat exchange performance is poor.

In view of the above-mentioned problems, the present invention aims to provide a high-performance fin-tube heat exchanger in which the heat exchanger tubes and the fins are in close contact with each other even when manufactured by hydraulic tube expansion. The fin tube type heat exchanger of the present invention has a configuration in which both ends of a substantially U-shaped bend are inserted from the end of the heat transfer tube to a position where they overlap with a group of fins.

According to the above-described structure, the present invention can apply a sufficiently high water pressure to the curved fin-tube heat exchanger, and can bring the curved portion of the heat exchanger tube into sufficient contact with the fin group.

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

FIG. 1 shows a sectional view of a joint portion between a heat exchanger tube and a substantially U-shaped bend in a fin-tube heat exchanger according to an embodiment of the present invention. In the figure, 12 is a fin group, 13
14 is a heat exchanger tube, 14 is a substantially U-shaped bend, 16 is an end plate, and 16 is a brazing material for joining the heat exchanger tube 13 and the substantially U-shaped bend 14.

When connecting the approximately U-shaped bend 14 and the heat exchanger tube 13, approximately U-shaped
The end of the letter-shaped bend 14 is made into a tube and inserted into the heat exchanger tube 13. At this time, the tip of the substantially U-shaped bend 14 is inserted deeper than the end plate 16, that is, until it overlaps with the fin group 12. In brazing, the pressure resistance of the portion of the heat exchanger tube 13 that extends beyond the end plate 16 can be increased by infiltrating the brazing material up to the tip of the approximately U-shaped pen 14.

As described above, according to this embodiment, when the tip of the substantially U-shaped bend 14 is joined to the inside of the heat exchanger tube 13, the brazing material is inserted deeper than the end plate 16 and overlapped with the fin group 12. 16 flows between the heat exchanger tube 13 and the substantially U-shaped bend 14 to a position where it overlaps with the fin group, thereby increasing pressure resistance.

In this embodiment, the end of the substantially U-shaped bend 14 is contracted to have a diameter smaller than the inner diameter of the heat exchanger tube 13; however, the outer diameter of the substantially U-shaped bend itself is smaller than the inner diameter of the heat exchanger tube 13. You can make it into something.

Effects of the Invention The present invention allows the heat exchanger tube to be expanded with sufficiently high water pressure by inserting the tip of the approximately U-shaped bend from the end of the heat exchanger tube to a position where it overlaps with the fin group, and the curved portion of the heat exchanger tube can also be expanded with the fin group. This makes it possible to improve the performance of fin-tube heat exchangers.

[Brief explanation of drawings]

Fig. 1 is a sectional view of a joint between a heat exchanger tube and a substantially U-shaped bend in a fin-tube heat exchanger according to an embodiment of the present invention, and Fig. 2 is a partially curved fin-tube heat exchanger in a conventional example. FIG. 3 is a perspective view of the entire vessel, and FIG. 3 is a partial sectional view of FIG. 2. 12... Fin group, 13... Heat exchanger tube,
14... Roughly U-shaped bend. Name of agent: Patent attorney Toshio Nakao and 1 other person12
- Fin group 13 - Heat exchanger tube 14 - Route U Imoyoben E Figure 1

Claims (1)

[Claims] A group of fins arranged in large numbers at regular intervals, through which air flows, a heat transfer tube inserted through the fin group through which fluid flows, and connected to the heat transfer tube to change the flow direction of the fluid by 180 degrees. 1. A fin-tube heat exchanger comprising a substantially U-shaped bend, wherein both ends of the substantially U-shaped bend are inserted from the end of the heat transfer tube to a position where they overlap with the fin group.