JP2001116488A - Plate fin for air-conditioning heat exchanger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a plate fin for air-conditioning heat exchanger which has a small circulation resistance on the air-side and can smoothly drain off condensate. SOLUTION: Trapezoid louvers 2b are formed on the base surface 2a of the plate of a plate fin 2 by cutting and raising the surface 2a and a recessed groove section 2c is provided at the central position of each louver 2b in the width direction. The groove section 2c is formed over the full length of the louver 2b between both raised end faces 2e of the louver 2b.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a plate fin of an air conditioner heat exchanger used as an evaporator.
More particularly, the present invention relates to a structure having a structure capable of smoothly removing condensed water on the surface of a plate fin.

[0002]

2. Description of the Related Art Plate fins of an air-conditioning heat exchanger used as an evaporator have been formed as shown in FIGS. 6 and 7, for example. FIG. 6 is a front view of a main part of a conventional plate fin, and FIG. 7 is a schematic sectional view taken along the line VII-VII. The plate fins 9 are formed by pressing many thin louvers 2 on a plate base surface 2a by pressing a thin metal plate.
b and the tube insertion holes 1 are formed at regular intervals. The tube insertion hole 1 is raised at the edge of the hole, and the rising height is the interval of the fin pitch of the plate fins 9. The trapezoidal louver 2b has a plate fin 9
Are formed in parallel with the longitudinal direction, and both sides in the width direction are cut and raised. Then, a large number of plate fins 9 aligned with each other are arranged in parallel, the tubes are inserted into the respective tube insertion holes 1, and the outer periphery of the tubes and the tube insertion holes 1 are fixed in contact with each other, and the ends of the tubes are separated from each other. A meandering refrigerant flow path is formed by connecting with a U-bend tube to complete the core. The longitudinal direction of the plate fins 9 is located in the direction of gravity, the air flow is circulated in the plane direction of the plate fins 9, and the refrigerant in a gas-liquid two-phase state is circulated in the tubes, so that the air-conditioning heat exchanger is formed. Make up. FIG. 8 is a cross-sectional view showing another example of the plate fin 10. In this example, trapezoidal louvers 2b are formed by cutting and raising alternately on the front side and the back side of the plate base surface 2a. .

[0003]

SUMMARY OF THE INVENTION There is a demand for a heat exchanger for air conditioning that is thin, compact, and has good heat exchange performance. As one of means for improving the heat exchange performance, a fin pitch is reduced, and more plate fins are arranged in parallel to increase a heat radiation area. When the fin pitch is reduced, the flow resistance of the airflow flowing between the plate fins increases. In particular, when a large number of trapezoidal louvers 2b are cut and raised on the front side and the back side of the plate base surface 2a as in a plate fin 10 as shown in FIG. 8, the flow resistance on the air side becomes larger. There are drawbacks. In order to reduce the air flow resistance, a wide trapezoidal louver 2b may be cut and formed only on one surface of the plate base surface 2a as shown in FIG. Then, there is a problem that it is difficult to remove the condensed water adhering to the surface of the plate fin 9. That is, in FIG. 6, the condensed water stays near the upper end edge of each trapezoidal louver 2b, and a part of the surface of the plate fin 9 is covered with the water film, so that the air flow directly contacts the surface of the plate fin 9 And the heat exchange performance is reduced. Therefore, an object of the present invention is to provide a plate fin capable of increasing the width of the trapezoidal louver 2b and reducing the condensed water smoothly in order to reduce the fin pitch and reduce the air flow resistance.

[0004]

According to the first aspect of the present invention, a large number of elongated plate fins 2 provided with a plurality of tube insertion holes 1 are arranged in parallel through small gaps. A core 4 is formed by inserting a tube 3 into the tube 3. The longitudinal direction of the plate fins 2 is arranged in the direction of gravity, and a refrigerant in a gas-liquid two-phase state flows through each tube 3. In the plate fins of the air-conditioning heat exchanger through which air flows, a large number of trapezoidal louvers 2b each having a trapezoidal shape with respect to the plate base surface 2a of each plate fin 2 are cut and raised on both sides in the width direction. The trapezoidal louvers 2b are formed so as to be bent in the widthwise middle positions of the respective trapezoidal louvers 2b. The concave grooves 2c are formed on both sides of the trapezoidal louvers 2b over the entire length thereof. A plate fin heat exchanger for air conditioning, characterized in that it is formed to the end surface 2e. According to a second aspect of the present invention, in the first aspect, the trapezoidal louvers 2b are plate fins of an air-conditioning heat exchanger disposed between the respective tube insertion holes 1.

[0005]

Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a schematic perspective view of a main part of a plate fin of an air conditioner heat exchanger according to the present invention, FIG. 2 is a front view thereof, and FIG. 3 is a sectional view taken along line III-III of FIG. Also,
FIG. 4 is an overall elevational view, and FIG. 5 is a schematic view of an air-conditioning heat exchanger in which the core 4 is constituted by the plate fins 2. In this air-conditioning heat exchanger, a number of elongated plate fins 2 are arranged in parallel, and tubes 3 are inserted through the tube insertion holes 1 to form a core 4. The longitudinal direction of each plate fin 2 is arranged in the direction of gravity. In addition, a refrigerant in a gas-liquid two-phase state flows in each tube 3, and an air flow 7 flows in the width direction of the plate fin 2 as shown in FIG. 5.

As shown in FIGS. 1 to 3, each of the plate fins 2 has a large number of trapezoidal louvers 2b formed in a trapezoidal shape with respect to a plate base surface 2a, and both sides in the width direction are cut and raised, and are formed so as to rise in the longitudinal direction. Have been. The trapezoidal louver 2b is formed with a concave groove portion 2c having a semicircular cross section at the center position in the width direction, and the concave groove portion 2c is formed over the entire length of the trapezoidal louver 2b and up to both rising end surfaces 2e. I have.
As shown in FIG. 4, each trapezoidal louver 2b is cut and raised between a large number of tube insertion holes 1 arranged in a staggered manner. The tube insertion hole 1 has a burring portion 8 at the edge of the hole, and the trapezoidal louvers 2b are formed by cutting and raising only on the protruding side of the burring portion 8. In addition, the height of the burring portion 8 regulates the fin pitch of the plate fins 2 arranged in parallel, and the height is smaller than that of a conventional plate fin.
1.2 mm or less. The width of each trapezoidal louver 2b is at least twice the width of the conventional one. The conventional fin pitch is about 1.2 mm to 1.5 mm, and the width of the trapezoidal louver is
It was about 1.0 mm.

A large number of plate fins 2 aligned in this manner are arranged side by side with a fin pitch of 1.2 mm or less, and a tube 3 is inserted into a tube insertion hole 1 thereof. Press the tool
The outer periphery of the tube 3 and the inner periphery of the tube insertion hole 1 are fixed by crimping. Then, the ends of each tube 3 are connected by a U-bend tube to form a meandering refrigerant flow path to form the core 4 (FIG. 5). Then, the core 4 is provided inside the casing 5 so that the longitudinal direction of the plate fins 2 is arranged in the direction of gravity, and a fan 6 is provided at the lower end thereof. By driving the fan 6, the airflow 7 is taken in from the entire surface of the core 4, and flows out from the lower end of the casing 5. Then, while the airflow 7 flows through the core 4,
Heat exchange takes place between the refrigerant and the airflow 7. At this time, FIG.
In this case, condensed water is generated on the surface of the plate fin 2. The condensed water flows down on the surface of the plate base surface 2a in the portion where the trapezoidal louver 2b does not exist, and in the portion where the trapezoidal louver 2b exists, the rising end surface 2a.
From e, the condensed water is guided to the groove 2c and flows down. Finally, the condensed water is guided to the outside from the drain pan.

[0008]

The plate fin of the air conditioner heat exchanger according to the present invention has a groove 2c formed at a widthwise intermediate position of each trapezoidal louver 2b, and the groove 2c includes a rising end face 2e. Since it is formed over the entire length, condensed water staying on the rising end face of the trapezoidal louver 2b is smoothly removed downward through the entire length, and the heat exchange performance can be improved. That is, the condensed water on the surface of the plate fin is eliminated to expose the plate surface, and the air flow can flow directly to the surface of the plate fin. Further, since the concave groove portion 2c is formed by bending the trapezoidal louver 2b, the flow resistance to the air flow can be suppressed relatively small, and the flow of the air flow can be performed smoothly. In addition, the air-side pressure loss can be reduced, and an air-conditioning heat exchanger having relatively small blowing power can be provided. Alternatively, if the blowing power is the same, it is possible to provide an air-conditioning heat exchanger having a high heat exchange performance by increasing the blowing amount.

[Brief description of the drawings]

FIG. 1 is a schematic perspective view of a main part of a plate fin of an air conditioning heat exchanger according to the present invention.

FIG. 2 is a front view of the plate fin.

FIG. 3 is a sectional view taken along the line III-III in FIG. 2;

FIG. 4 is an overall elevation view of a plate fin of the air conditioning heat exchanger of the present invention.

FIG. 5 is a view showing a core 4 formed by the plate fins 2;
Schematic diagram of an air conditioning heat exchanger having the same.

FIG. 6 is a front view of a main part of a conventional plate fin 9;

FIG. 7 is a schematic view taken along the line VII-VII of FIG. 6;

FIG. 8 is a schematic cross-sectional view of another conventional plate fin 10;

[Explanation of symbols]

 Reference Signs List 1 tube insertion hole 2 plate fin 2a plate base surface 2b trapezoidal louver 2c concave groove 2e rising end surface 3 tube 4 core 5 casing 6 fan 7 air flow 8 burring section 9 plate fin 10 plate fin

Claims (2)

[Claims] 1. A large number of elongated plate fins 2 provided with a plurality of tube insertion holes 1 are arranged in parallel through small gaps,
A core 4 is formed by inserting the tubes 3 into the tube insertion holes 1, the longitudinal direction of the plate fins 2 is arranged in the direction of gravity, and a refrigerant in a gas-liquid two-phase state flows through each tube 3. In the plate fins of the air-conditioning heat exchanger through which air flows in the width direction of the plate fins 2, each of the plate fins 2 has a large number of trapezoidal louvers 2b having a trapezoidal shape with respect to the plate base surface 2a. Each of the trapezoidal louvers 2b is formed with a bent groove 2c at an intermediate position in the width direction of the trapezoidal louver 2b.
A plate fin for an air-conditioning heat exchanger, wherein the plate fin is formed up to both rising end faces 2e over the entire length of b. 2. The plate fin of an air-conditioning heat exchanger according to claim 1, wherein the trapezoidal louvers 2b are arranged between the respective tube insertion holes 1.