JPS61243291A - Finned heat exchanger - Google Patents

Abstract

PURPOSE:To contrive the cost down and the improvement of heat transfer performance of the heat exchanger by a method wherein belt-type protuberances, formed continuously on the front and rear surfaces of a fin so as to be opposed to the airflow in the heat exchanger, are provided on the flat fin between heat transfer tubes. CONSTITUTION:The finned heat exchanger is formed by a method wherein the heat transfer tubes 8 are inserted vertically into the fin collars 7 of the flat plate fin 6 and the fin collars 7 and the heat transfer tubes 8 are integrated by expanding the heat transfer tubes 8 from the inside thereof. Upon expanding the tubes, the belt-type protuberances 10 are formed continuously on the front and rear surfaces of the flat plate fin 6 between the heat transfer tubes in parallel to the longitudinal direction of the fin 6 where by the flat plate fin 6, weakened in the strength thereof by providing slit type cut-ups 11, can be reinforced sufficiently and smooth expanding work of the tube may be effected. The airflow, passing between the slit type cut-ups 11 provided on the front and rear surfaces of the flat plate fin 6, collides against the belt type protuberances 10 and the flow thereof is disturbed, whereby the formation of temperature boundary layer is interferred. Accordingly, a temperature gradient on the surface of the fin is increased and heat exchange between the fins and the airflow is promoted, whereby the heat transfer coefficient may be improved.

Description

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

BACKGROUND OF THE INVENTION Conventionally, this type of heat exchanger has a flat plate fin group 1 arranged in parallel at regular intervals as shown in FIG.
In recent years, such large heat exchangers have been constructed with a heat exchanger tube group 2 inserted at right angles to the fin group 1, and air flows between the fin groups 1 in the direction of the arrow 3 to exchange heat with the fluid inside the tubes. There is a demand for smaller size and higher performance, and in order to reduce the thermal resistance on the air side, appropriate improvements have been made to the fin surface, as shown in FIG. 5, for example.

In this case, the heat transfer performance is improved by providing slit-like cutouts 4 and 5 with two side edges opened on the fin surface.

Problems to be Solved by the Invention However, in such a configuration, the slit-like cutouts 4, 6
Because the fins are cut parallel to the longitudinal direction of the fins, they tend to be weak in strength. Therefore, in order to increase the strength, the fin plate thickness must be increased, and this is because the fin heat exchanger This has caused problems such as an increase in weight and an increase in cost.

Therefore, the present invention aims to improve the heat transfer performance by improving the strength of the fins and reducing the thickness of the fins, in other words, reducing the cost. be.

Means for Solving the Problems Technical means of the present invention for solving the above-mentioned problems A band-shaped protrusion, in which protrusions facing the airflow are continuously provided on the front and back sides, is provided on the flat plate fin between the heat exchanger tubes. It is.

For production The effect of this technical means is as follows.

In other words, since the above-mentioned band-shaped protrusions are provided, the strength of the fins, especially in the longitudinal direction of the fins, can be obtained, the fins can be made thinner, and the cost of the heat exchanger with fins can be reduced. .

Further, the flow of the airflow flowing near the band-like protrusions is disturbed by the band-like protrusions, thereby preventing the formation of a temperature boundary layer, thereby promoting heat exchange between the fins and the airflow, and improving the heat transfer coefficient. Moreover, since the strip-shaped protrusions are continuously provided on the front and back sides, the heat transfer coefficient is improved on the front and back sides of the fin.

EXAMPLE Hereinafter, an example of the present invention will be described based on the accompanying drawings.

As shown in Figure 1 a and b, 6 are arranged at regular intervals,
Flat fins through which air flows, 7 is a flat fin e
Fin collars 8 with burring on the top are heat transfer tubes that are inserted perpendicularly into the flat fins 6 and through which the refrigerant flows, and the heat transfer tubes 8 are arranged in a staggered manner on the flat fins 6. A band-shaped protrusion 1o is provided on the flat plate fins θ between the heat exchanger tubes 8 disposed in a direction perpendicular to the airflow direction 9, the longitudinal direction of which is perpendicular to the airflow direction 9. The band-shaped protrusion 10 has two side portions facing the airflow that are continuous with the plane portion of the flat fin, and protrusions are provided continuously on the front and back sides. Moreover, on the flat plate fins e before and after the strip-like projection 1o, slit-shaped cut-and-raised ribs 11 with openings on two sides facing the airflow are installed parallel to the longitudinal direction of the strip-like projection 1o.

Next, the operation of the structure of the burnt embodiment will be explained.

The heat exchanger with fins integrates the fin collar 7 and the heat exchanger tube 8 by inserting the heat exchanger tube 8 perpendicularly into the fin collar 7 of the flat plate fin 6 and expanding the heat exchanger tube 8 from inside. It is formed. During this tube expansion, strip-like protrusions 10 are continuously provided on the front and back sides of the flat plate fins 6 in parallel to the longitudinal direction of the flat plate fins 6 on the flat plate fins e between the heat transfer tubes 8.
By providing the slit-shaped cut-and-raised portions 11, the flat plate fins e, which become weak in strength, can be sufficiently reinforced, and smooth pipe expansion work becomes possible. Therefore, since the strength is increased by providing the band-like projections 10, the fin material can be made thinner, and costs can be reduced.

Furthermore, the airflow passing between the slit-like cutouts 11 provided on the front and back sides of the flat plate fin 6 collides with the band-like protrusion 1o and is disturbed, thereby preventing the formation of a temperature boundary layer. Therefore, as the temperature gradient on the fin surface becomes larger, heat exchange between the fin and the airflow is promoted, and the heat transfer coefficient is improved.

Moreover, since the band-like projections 1o are provided on the front and back sides of the flat plate fins 6, the heat transfer coefficient is improved on the front and back sides of the flat plate fins 6.

Next, other embodiments of the present invention will be described.

FIG. 2v shows another embodiment, in which:
The strip-shaped protrusion 10' is provided such that the longitudinal direction of the strip-shaped protrusion 10' has an inclination angle with respect to the airflow direction 9. Further, on the flat plate fins 6 before and behind the band-like projection 10', slit-shaped cut-outs 11 are formed parallel to the longitudinal direction of the band-like projection 10'.
' is provided.

In this case, the reinforcing effect of the fin material by the strip projections 10' is almost the same as in the first embodiment, or rather the strength in the width direction (direction perpendicular to the longitudinal direction) of the fin is increased.

Furthermore, since the longitudinal direction of the strip protrusion 10' has an inclination angle with respect to the air flow direction 9, the flow 12 overcoming the strip protrusion 10' and the flow 13 along the strip protrusion 10' interfere with each other, causing the strip protrusion 10 to A vortex is generated diagonally behind '. In addition to this, the effect of preventing the formation of the temperature boundary layer described in the first embodiment is added to promote heat exchange between the fins and the airflow, improving the heat transfer coefficient.

In addition, the above 1. In the second embodiment, the band-shaped protrusion 10,
Although slit-shaped cut-and-raised portions 11° 11' are provided before and after 10', the same effect can be obtained by providing a looper instead.

Next, a third embodiment of the present invention will be described.

FIG. 3 shows a third embodiment, in which an opening 14 is provided in the wall of the band-like projection 10' facing the airflow. Therefore, in terms of strength of the fin material, the first and second
Although it is inferior to the embodiment shown in FIG.
The so-called mixing effect obtained by flowing in and out through the openings 14, together with the boundary layer front effect at the ends of the openings 14, further improves the surface heat transfer coefficient of the fins.

Effects of the Invention The present invention consists of flat plate fins that are arranged in parallel at regular intervals, through which air flows, and heat transfer tubes that are inserted at right angles to the flat fins, through which fluid flows, and which face the air flow. The strength of the fin material can be improved by providing a band-like projection on the flat plate fin between the heat transfer tubes, which has continuous protrusions on the front and back sides. The cost of the exchanger can be reduced. In addition, the band-like protrusions disturb the airflow in the vicinity and prevent the formation of a temperature boundary layer, thereby promoting heat exchange between the fins and the airflow and improving heat transfer performance.

[Brief explanation of the drawing]

FIG. 1 is a plan view and a sectional view of a main part of a finned heat exchanger according to a first embodiment of the present invention, and FIG. 2 is a main part of a finned heat exchanger according to a second embodiment of the present invention. 3 is a perspective view of a main part of a finned heat exchanger according to a third embodiment of the present invention; FIG. 4 is a perspective view of a conventional finned heat exchanger; FIG. 6 is a plan view and a sectional view of a main part; 2 is a plan view and a sectional view of a main part of the finned heat exchanger. 6... Flat plate fin, 8... Heat exchanger tube, 9
...Airflow direction, 10, 10', 10'
... Band-like projection, 11°11' ... Slit-like cut and rise, 14 ... Opening. 6----Tai, muffin 5th figure 8-den #S Kan No. 4 figure fs5 figure ＾ C top 6

Claims (3)

[Claims] (1) Consists of flat plate fins that are arranged in parallel at regular intervals, through which air flows, and heat transfer tubes that are inserted at right angles to the flat plate fins and through which fluid flows. A heat exchanger with fins, in which a continuous band-shaped protrusion is provided on a flat plate fin between the heat transfer tubes. (2) The finned heat exchanger according to claim 1, wherein the longitudinal direction of the band-like protrusions has an inclination angle with respect to the airflow direction. (3) The finned heat exchanger according to claim 1, wherein an opening is provided in a part of the band-shaped projection.