JPH02166394A - Heat exchanger with fin - Google Patents

Abstract

PURPOSE:To improve the fin efficiency and raise the heat exchange performance a great deal by constituting the cutting line of the row of plate-shaped fins with a curved line or bending line which runs farther from the heat transfer pipe with respect to the centerline in the row near heat transfer pipes and runs nearer to the heat transfer pipe with respect to the centerline in the row near the central section of the heat transfer pipes which are close to one another in the direction of steps. CONSTITUTION:Because a plate-shaped fin 11 is cut near a heat transfer pipe 2a to be farther from the heat transfer pipe 2a with respect to the centerline 3 in the rows, average heat transfer distance from the heat transfer pipe 2a to the surface of the plate-shaped fin 11 becomes short, giving better fin efficiency. Further, near the central section between the heat transfer pipe 2a and heat transfer pipe 2b which are mutually close in the direction of the steps the plate-shaped fin 11 is cut so as to be near the heat transfer pipes 2a and 2b with respect to the centerline 3 in the rows, and near the heat transfer pipe 3c which is near the heat transfer pipes 2a and 2b in the direction of the rows the plate shaped fin 11 is cut to be farther from the heat transfer pipe 2c with respect to the centerline 3 in the rows. Here, the outer pipe diameter D of the heat transfer pipes 2a and 2b is D >= 8.5mm and the ratio of the pitch Pr of the rows to the pitch Ph of the steps is Pr/Ph >= 0.7.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a finned heat exchanger used in cooling systems such as air conditioners and refrigerators.

BACKGROUND OF THE INVENTION In recent years, as air conditioners, refrigerators, etc. have become smaller and lower in cost, there has been a demand for increasingly improved performance and lower costs for the finned heat exchangers that are their constituent parts.

An example of a conventional finned heat exchanger will be described below with reference to the drawings. 6 and 6 show a conventional finned heat exchanger. 1 is a plate-like fin, 2,2
Reference numerals a, 2b, and 2a are heat transfer tubes that are inserted into the plate-like fins 1 and are in close contact with each other, through which a refrigerant flows. The plate-shaped fins 1 are cut in a straight line between the rows for the purpose of preventing heat transfer between the heat transfer tubes 2 having different temperatures or for the purpose of making the fins easier to manufacture in the manufacturing process.

The heat exchanger tube 2 has a tube outer diameter D≦8.5 and a row pitch P.

and the step pitch Ph ratio Pr/Ph≦0.7.

Problems to be Solved by the Invention However, in the conventional configuration, the plate-like fins 1 are divided linearly between rows, and the outer diameter of the heat exchanger tubes 2 is D≦8.5.
ms, the ratio of row pitch P and step pitch Ph is Pr/
Since Ph≦0.7, the fin portions of the plate-like fins 1 in the row direction with respect to the heat exchanger tubes 2 are shorter than those in the step direction, and the fin efficiency is very poor. Also, for the step pitch Ph,
If the row pitch Pr is made sufficiently large, it will be possible to increase the size and
This will increase costs. Furthermore, if the tube diameter is increased to increase fin efficiency, air resistance will increase and the size will increase.

The present invention solves the conventional problems and is miniaturized.

It is an object of the present invention to provide a fin-equipped heat exchanger that reduces costs, improves the fin efficiency of plate-shaped fins divided between rows, and significantly improves heat exchange performance.

Means for Solving the Problems In order to achieve this object, the finned heat exchanger of the present invention is provided such that the row cutting line of the plate-like fins is closer to the center line between the rows than the heat exchanger tubes in the vicinity of the heat exchanger tubes. In the vicinity of the center between the heat transfer tubes that are far apart and adjacent in the row direction, a curved line or a bent line that is closer to the heat transfer tubes is formed with respect to the inter-row center line. Here, the outer diameter Fi of the heat exchanger tubes is 8.5 m or less, and the ratio of the row pitch Pr to the step pitch Ph is P, /Ph≦0.7.

Effect With this configuration, in a finned heat exchanger having plate-shaped fins cut between rows, the heat exchanger tubes are far away from the center line between rows in the vicinity of the heat exchanger tubes, and the adjacent heat exchanger tubes in the row direction are Near the center of the heat tubes, the center line between the rows is cut with a curve or curved line that is close to the heat transfer tubes, so the average heat conduction distance from each heat transfer tube to the plate-like fin surface is Shorter fins improve fin efficiency. By having this configuration, the ratio of the row pitch Pr to the step pitch Ph of the heat exchanger tubes is P, /Ph≦0.7, and the pipe diameter of the heat transfer tubes is D≦8.6. In a fin-equipped heat exchanger that is smaller in size and lower in cost, even if the plate-like fins are divided between rows, the heat exchange performance can be improved by increasing the fin efficiency.

EXAMPLE Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 1 shows a sectional view of a finned heat exchanger according to an embodiment of the present invention. Note that the same configurations as those of the conventional example will be given the same numbers and the description thereof will be omitted. In the vicinity of the heat exchanger tubes 2a, the row cutting line of the plate-like fins 11 is further away from the inter-row center line 3 than the heat exchanger tubes 2a, and in the vicinity of the center of the heat exchanger tubes 2a and 2b adjacent in the step direction, the row The curved line is close to the heat transfer tube with respect to the center line 3. Further, both ends of the fin 11 are similarly cut. Here, heat exchanger tube 2a and heat exchanger tube 2
The outer diameter of the tube b is D≦8.5 mg, and the ratio of the row hit P and step pitch Ph is P, /Ph≦0.7.

The operation of the finned heat exchanger configured as described above will be explained below. ÷φ In the vicinity of the temporarily cut plate-like fins 11, the heat exchanger tubes 2a are cut so as to be farther from the inter-row center line 3 than the heat exchanger tubes 2a, so that there is no flow from the heat exchanger tubes 2a to the surface of the plate-like fins 11. The average heat conduction distance becomes shorter,
Fin efficiency is improved. In addition, near the center of the heat exchanger tubes 2a and 2b that are adjacent to each other in the row direction, the plate-like fin structure is
The heat exchanger tube 2a and the heat exchanger tube 2
In the vicinity of the heat exchanger tube 2C adjacent to b in the row direction, it is cut so as to be farther from the inter-row center line 3 than the heat exchanger tube 2C. Therefore, the same effect as the rows of heat exchanger tubes 2a and 2b can be obtained in this row of heat exchanger tubes 2C. Moreover, since the end of the plate-shaped fin 11 on the side far from the inter-row center line 3 is also cut by the bent line, the plate-shaped fin 11 can improve fin efficiency without increasing material cost.

FIG. 3 is a diagram showing the relationship between the ratio Pr/Ph of the row pitch Pr to the step pitch Ph and the fin efficiency when the heat exchanger tube outer diameter D = 8.5 tm.

The fin efficiency of the finned heat exchanger A1 of this embodiment is as follows: Significantly improved.

Figure 4 shows the ratio Pr/Ph of the row pitch PK and the step pitch Ph.
It is a figure showing the relationship between heat exchanger tube outer diameter and fin efficiency at =07. The fin efficiency of the finned heat exchanger A2 of this embodiment is significantly improved compared to the fin efficiency of the conventional finned heat exchanger B2 when the heat exchanger tube outer diameter D≦8.5 van.

A second embodiment of the present invention will be described below with reference to FIG. Regarding the same configuration as one embodiment,
The same number will be assigned and the explanation will be omitted. 12 & and 12
b is a plate-shaped fin, and the ends of the plate-shaped fins 12a and 12b that are far from the inter-row center line 3 are cut in a straight line to form the inter-row center line 3 of the plate-shaped fins 12M and the plate-shaped fins 12b. The end closer to the front end is cut along a bending line as in the embodiment.

The operation of the finned heat exchanger constructed as above will be explained below.

Since the end portions of the plate-like fins 12a and the plate-like fins 12b farther from the inter-row center line 3 are cut into a straight line, the volume of the finned heat exchanger does not change. Furthermore, between the rows, the plate-like fins 12a and the plate-like fins 1
Since the row cutting line 2b is a bent line, fin efficiency can be improved.

In addition, in the embodiment and the second embodiment, the plate-like fin 1
1. The same effect can be obtained even if the row cutting line, which is the bent line of the plate-like fins 12a and the plate-like fins 12b, is a smooth curve.

Effects of the Invention As described above, the present invention is arranged in a plurality of rows and has a row pitch P.
In the vicinity of the heat exchanger tubes where the ratio of K to step pitch Ph is P, /Ph≦0.7, and the outer diameter D≦8!511 m, the row cutting line of the plate-shaped fins cut between the rows is , consists of a curved line or bent line that is farther away from the heat exchanger tubes with respect to the center line between rows, and closer to the heat exchanger tubes with respect to the center line between rows near the center of the heat exchanger tubes adjacent in the row direction. Therefore, it is possible to realize an excellent heat exchanger with fins that can significantly improve fin efficiency without increasing material costs.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a finned heat exchanger according to a first embodiment of the present invention, FIG. 2 is a cross-sectional view of a finned heat exchanger according to a second embodiment of the present invention, and FIG. 3 is a cross-sectional view of a finned heat exchanger according to a second embodiment of the present invention. A characteristic diagram showing the relationship between the row pitch and step pitch ratio and fin efficiency of the finned heat exchanger of the first embodiment. A characteristic diagram showing the relationship, FIG. 5 is a sectional view of a conventional finned heat exchanger, and FIG. 6 is a perspective view of the same finned heat exchanger. 11, 12a, 12b... plate-shaped fins,
2a. 2b, 2c... Heat exchanger tube, 3... Center line between rows, Pr... Row pitch, Ph... Step pitch, D...・Outer diameter of heat transfer tube. Name of agent: Patent attorney Shigetaka Awano and 1 other person No. 3
Figure Pp/Ph Figure 4

Claims (2)

[Claims] (1) A large number of plate-shaped fins are arranged in parallel and airflow flows between them, and the plate-shaped fins are arranged and inserted so that the ratio of row pitch Pr to step pitch Ph is Pr/Ph≦0.7, Outer diameter D≦8.5 of multiple rows of heat transfer tubes through which refrigerant flows
mm, and the plate-like fins are arranged so that the row cutting line is further away from the heat exchanger tubes with respect to the inter-row center line in the vicinity of the heat exchanger tubes, and the center between adjacent heat exchanger tubes in the step direction. The heat exchanger with fins has a curved line or a curved line that is close to the heat transfer tube with respect to the center line between the rows. (2) The heat exchanger with fins according to claim 1, wherein one of the row cutting lines of the plate-like fins is a straight line.