JPH074883A - Plate fin and tube type heat exchanger - Google Patents

Abstract

PURPOSE:To improve the heat transfer efficiency of a heat exchanger without increasing the flowing resistance of air and without impairing the water discharging performance of drain by a method wherein an air flow-in side edge of plate fin is corrugated and inclined. CONSTITUTION:Since an air flow-in side edge 4 of a plate fin 1 is corrugated on a plane in parallel with an air flowing direction, the length of the air flow-in side edge 4 is elongated, and the area near the edge is increased. As a result, an air side heat transfer rate of the plate fin 1 is entirely increased. Since an end surface 6 of the air flow-in side edge 4 is inclined in the thickness direction of the plate fin 1, the resistance when air strikes against the end surface 6 is decreased, an eddy flow generated from a side edge of the end surface 6 is reduced and at the same time the thickness of an interface layer of air stream is also reduced. Drain condensed on the surface of the plate fin 1 is displaced to the side part while passing above the inclined end surface 6, drops from a ridge 8 where the end surface 6 and the surface 7 meet each other and the drain is held within a recessed part 9 through its surface tension.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plate fin and tube heat exchanger suitable for an outdoor heat exchanger and an indoor heat exchanger of an air conditioner.

[0002]

2. Description of the Related Art FIG. 3 shows an example of a conventional plate fin-and-tube heat exchanger of this type. The plate fin-and-tube heat exchanger 10 has a large number of flat plate fins 1 arranged in parallel at a small distance from each other and extending substantially vertically, and a plurality of plate fins 1 penetrating these plate fins 1 at a right angle to each other. It is provided with a large number of tubes 2 that extend substantially horizontally at intervals.

A large number of louvers 3 are cut and raised on the entire surface of the plate fin 1, and the air inflow side edge 4 thereof is made straight.

The air horizontally flows through the gaps between the plate fins 1 and the tubes 2 as indicated by the white arrows, and in this process, heat exchanges with the refrigerant flowing through the tubes 2.

[0005]

In the above-mentioned conventional plate fin and tube heat exchanger, since the air inflow side edge 4 of the plate fin 1 having the best air side heat transfer coefficient is a straight line, There is a problem that the heat transfer performance of this heat exchanger is not sufficient.

The present invention has been invented to solve the above problems, and an object thereof is to provide a plate fin-and-tube heat exchanger having excellent heat transfer performance. Another object of the present invention is to provide a plate fin-and-tube heat exchanger in which the pressure loss of air flowing through the heat exchanger is small. Still another object of the present invention is to provide a plate fin and tube type heat exchanger capable of easily discharging the drain condensed on the surface of the plate fin.

[0007]

SUMMARY OF THE INVENTION The present invention has been invented to achieve the above object, and the gist of the first invention is that a large number of elements are arranged in parallel with each other at a minute interval. In a plate fin-and-tube type heat exchanger comprising a plate fin and a plurality of tubes penetrating these plate fins at right angles, the air inlet side edge of the plate fin is corrugated on a plane parallel to the air flow direction. The plate fin-and-tube heat exchanger is characterized in that the end face is inclined with respect to the thickness direction of the fin.

The gist of the second invention is that a plate fin-and-tube is provided with a large number of plate fins arranged in parallel with each other at a minute interval and a plurality of tubes penetrating the large number of plate fins at right angles. In the plate heat exchanger, the plate fin-and-tube heat exchanger is characterized in that only the edge of the plate fin on the air inflow side is corrugated on a plane orthogonal to the air flow direction.

[0009]

In the first aspect of the invention, since the edge of the plate fin on the air inflow side is corrugated on a plane parallel to the air flow direction, the area of the edge of the air inflow side increases. Further, since the end face of the air inflow side edge is inclined with respect to the thickness direction of the fin, not only the inflow resistance of air is reduced but also the drain condensed on the surface of the plate fin is guided to this inclined end face. It is smoothly discharged from one side.

In the second aspect of the invention, since only the air inflow side edge of the plate fin is corrugated on the plane orthogonal to the air flow direction, not only the area of the air inflow side edge is increased but also the air is increased. Since the hydrodynamic wetting edge of the edge against which the heat exchanger collides is large, the pressure loss of the air flowing through the heat exchanger is small.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A first embodiment of the invention is shown in FIG. The air inflow side edge 4 of each plate fin 1 is corrugated on a plane parallel to the air flow direction indicated by a white arrow. The end surface 6 is inclined with respect to the thickness direction of the plate fin 1, and therefore the inclined surface 6a and the inclined surface 6b are formed.
The ridgeline 5 formed by the intersection of the two is shown in Fig. 1 (C).
As shown in, it is inclined to one side. Other configurations are similar to those of the conventional one shown in FIG. 3, and corresponding members are designated by the same reference numerals.

However, since the air inflow side edge 4 of the plate fin 1 is longer than the conventional one, the area in the vicinity of the air inflow side edge 4 having the best air side heat transfer coefficient is increased. As a result, the air-side heat transfer coefficient of the plate fins 1 is improved as a whole, so that the heat transfer performance of the heat exchanger is improved. Further, since the end surface 6 of the air inflow side edge 4 is inclined in the thickness direction of the plate fin 1, the resistance when air collides with the end surface 6 is small, and the air is generated from the side edge of the end surface 6. Not only are there fewer vortices, but also the thickness of the boundary layer of the airflow is smaller.

Even when water in the air is condensed to flow on the surface of the plate fin 1 as drain when flowing through the heat exchanger, the drain flows laterally in the process of flowing down on the inclined end surface 6. Since the end surface 6 and the surface 7 cross each other and fall downward from the ridge line 8 formed by the intersection of the end surface 6 and the surface 7, the drain inside the recess 9 formed between the downward end surface 6a and the upward end surface 6b. Therefore, the air flow that is held by the surface tension and flows into the gap of the plate fin 1 is not hindered.

A second embodiment of the invention is shown in FIG. In the second embodiment, only the air inflow side edge 4 of the plate fin 1 is corrugated on the plane orthogonal to the air flow direction shown by the white arrow, and the other remains flat. Other configurations are similar to those of the conventional one shown in FIG.

However, since the length of the air inflow side edge 4 is long, the area in the vicinity thereof is increased and the hydrodynamic wetting edge of the air colliding with the end surface 5 is increased, so that the air flow overresistance is increased. Does not increase. Further, the air flowing in from the air inflow side edge 4 causes a secondary flow when flowing along the corrugated surface, so that the heat transfer performance of the plate fin 1 is improved.

[0016]

According to the first aspect of the present invention, since the air inlet side edge of the plate fin is corrugated on a plane parallel to the air flow direction, the length of the air inlet side edge becomes longer and its vicinity. Area increases. Further, since the end face of the air inflow side edge is inclined with respect to the thickness direction of the fin, not only the inflow resistance of air is reduced but also the drain condensed on the surface of the plate fin is guided to this inclined end face. It is smoothly discharged from one side. As a result, the heat transfer performance of the heat exchanger can be improved without increasing the air flow resistance and without impairing the drainage drainage performance.

In the second aspect of the invention, since only the air inflow side edge of the plate fin is corrugated on the plane orthogonal to the air flow direction, the length of the air inflow side edge becomes long and the vicinity thereof. As the area increases, the hydrodynamic wetting edge of the air inflow side edge increases. As a result, the heat transfer performance of the heat exchanger can be improved without increasing the air flow resistance.

[Brief description of drawings]

1 shows a first embodiment of the present invention, (A) is a partial external perspective view, (B) is a partial front view of a plate fin, (C).
FIG. 7B is a view taken along the arrow C in (B).

2A and 2B show a second embodiment of the present invention, in which FIG. 2A is a partial front view of a plate fin, and FIG. 2B is a view taken along the arrow B of FIG.

FIG. 3 is a partial external perspective view of a conventional plate fin-and-tube heat exchanger.

[Explanation of symbols]

 1 Plate fin 2 Tube 4 Air inflow side edge 6 End surface

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[Procedure amendment]

[Submission date] December 24, 1993

[Procedure Amendment 1]

[Document name to be corrected] Drawing

[Correction target item name] All drawings

[Correction method] Change

[Correction content]

[Figure 1]

[Fig. 2]

[Figure 3]

Claims (2)

[Claims] 1. A plate fin-and-tube heat exchanger comprising a large number of plate fins arranged in parallel with each other at a minute interval and a plurality of tubes penetrating the large number of plate fins at right angles. The plate fin-and-tube heat exchanger characterized in that the edge of the air inflow side of the plate is corrugated on a plane parallel to the air flow direction, and the end surface is inclined with respect to the thickness direction of the fins. . 2. A plate fin-and-tube heat exchanger comprising a large number of plate fins arranged in parallel with each other at a small interval and a plurality of tubes penetrating the large number of plate fins at right angles. A plate fin-and-tube heat exchanger characterized in that only the air inflow side edge of is formed in a corrugated shape on a plane orthogonal to the air flow direction.