JP2003322486A - Heat exchanger - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide structure of a heat exchanger for rapidly discharging condensate F generated between fins 6. <P>SOLUTION: A downstream side end part 2a of a flat tube 2 is formed of one member, a clearance 7 is formed between the downstream side end part 2a and a downstream side end part 3a of a fin 3, and an inclined surface is formed on the flat tube 2 so that the clearance 7 is wider toward a top of the flat tube 2. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a heat exchanger such as an evaporator of a vehicle air conditioner.

[0002]

2. Description of the Related Art Generally, a plurality of flat tubes in which a refrigerant flows and corrugated fins that exchange heat with air are alternately stacked and arranged, and the refrigerant flows in the flat tubes in the longitudinal direction of the flat tubes. There is known a heat exchanger in which air flows between the fins in a direction orthogonal to the flow direction of the refrigerant and the stacking direction of the flat tubes and the fins. As such a heat exchanger, for example, heat exchangers as shown in FIGS. 6 and 7 are known. Specifically, the flat tube 101 is formed by facing a pair of bowl-shaped plates 111 and joining the outer peripheral edge portions thereof. Tank portions 105 are formed at the upper and lower ends of the flat tube 101, respectively. Such a heat exchanger 10
At 0, the heat exchange air passes between the corrugated fins 103 in the front-back direction in FIG. In such an air flower, the flat tube 101 and the corrugated fins 103 have a front end portion and a rear end portion each having a shape as shown in FIG. 7. FIG. 7A is a cross-sectional view showing the rear end portions of the tube 101 and the fin 103 in the air flow direction. FIG. 7B is a side view of FIG. 7A viewed from the direction of arrow A. In such a heat exchanger 100, the condensed water generated between the fins 103 causes
1 flows into a space 107 formed between the fin 103 and the fin 103, and is discharged through the space 107.

However, if a large amount of condensed water is generated due to operating conditions, the space between the fins is closed by the condensed water accumulated at the rear end of the fin 103, which increases ventilation resistance and splashes the condensed water. May cause problems. Alternatively, when the air volume suddenly increases, a large amount of air must pass between the fins quickly, but even if a small amount of condensed water remains between the fins, the ventilation resistance Has a large effect, resulting in deterioration of heat exchange efficiency.

[0004]

As a solution to the above-mentioned problems of the prior art, there is known one disclosed in JP-A-64-41794. As shown in FIG. 8, the heat exchanger 2 of this publication has flat tubes 201 and corrugated fins 203 alternately stacked.
The flat tube 201 is formed by joining the outer peripheral edge portions of the pair of bowl-shaped plates 211. The joining portion 213 and the joining portion 213 are provided at the leeward side end and the windward side end of the flat tube 201, respectively.
The collar portion 215 is provided so as to be separated from the fin portion 203, and the collar portion 215 is separated from the end portion of the fin 203 by a predetermined distance (h). With such a configuration, the space 207
Condensed water accumulated in the water will leak from the gap of the predetermined interval (h).

However, in this publication, the flat tube 201 is limited to the type in which the bowl-shaped plates 211 face each other. That is, the space 2 is formed by using a bent part that fits two plates together.
07 and the interval (h) are provided. On the other hand, the flat tube formed by bending one thin plate by roll forming or the flat tube formed by extrusion molding at one time cannot provide the interval (h) as in the above publication. Therefore, in such a type of flat tube, that is, in a flat tube of a type that does not have a thin plate mating portion at the end of the flat tube, dew condensation water accumulates at the end of the fin, which increases ventilation resistance. Invited.

Further, in the above publication, the condensed water is once stored in the space 207, and the condensed water that cannot be contained in the space overflows from the interval (h) and overflows.
If too much condensed water is generated, it may not be able to overflow in time, and condensed water may remain between the fins to close the spaces between the fins.

According to the present invention, in order to solve the above problems, flat tubes and corrugated fins are alternately stacked and arranged, and air flows between the fins in a direction orthogonal to the stacking direction of the flat tubes and fins. In the heat exchanger where the leeward side end of the flat tube is composed of one member,
An object of the present invention is to provide a structure of a heat exchanger that can quickly discharge condensed water generated between fins.

[0008]

According to a first aspect of the present invention, a plurality of flat tubes in which a refrigerant flows and corrugated fins that exchange heat with air are alternately laminated and arranged, and the flat tubes are provided with a long length of the flat tubes. Refrigerant flows in the direction
In a heat exchanger in which air flows between the fins in a direction orthogonal to the flow direction of the refrigerant and the stacking direction of the flat tubes and the fins, the leeward side end of the flat tubes is composed of one member, A predetermined clearance is provided between the leeward side end and the end of the fin facing the end.

With this structure, the dew condensation water generated between the fins can be promptly discharged through the clearance, and ventilation resistance and flying water can be reduced.

According to a second aspect of the invention, in the heat exchanger according to the first aspect, the height of the leeward side end of the flat tube is
Since the height is set lower than the heights of other parts, the condensed water can be quickly discharged through the clearance. In particular, a large amount of condensed water increases the ventilation resistance at the leeward end of the fins, and in extreme conditions, even if the leeward end is blocked, the air will have the above clearance between the fins. Since it can flow through, it is possible to suppress an increase in ventilation resistance and prevent flying water and the like.

According to a third aspect of the present invention, in the heat exchanger according to the first or second aspect, the flat tube is formed by bending one thin plate by roll forming, so that the bent state should be set. The size of the clearance can be set, and the setting of the clearance is easy.

According to a fourth aspect of the present invention, in the heat exchanger according to the first or second aspect, the flat tube is integrally formed by extrusion molding, and a clearance can be provided at the same time during extrusion molding. No extra molding process is required, and an increase in manufacturing process and cost increase can be eliminated.

According to a fifth aspect of the present invention, in the heat exchanger according to any one of the first to fourth aspects, the height of the leeward side end of the flat tube is set so as to gradually decrease toward the tip. Therefore, the dew condensation water guided to the clearance from the rear end of the fin is quickly discharged without being stagnant in this clearance. Therefore, even when the amount of dew condensation water increases sharply, it is possible to reduce the amount of dew condensation water stagnating between the fins, so that the ventilation resistance can be reduced. Further, even when the air volume suddenly increases due to the operating state, the resistance when the air passes between the fins is small and the flying water can be reduced.

According to a sixth aspect of the present invention, in the heat exchanger according to the fifth aspect, the leeward side end portions of the flat tubes are directed from the flat surface portions in contact with the fins on both sides toward the intermediate portion separated from the fins. Since the taper is set to be gradually tapered, a clearance is provided between the fins on both sides of the flat tube toward the flat tube. Therefore, air is guided to the clearance from the fins on both sides, and ventilation resistance can be reduced.

According to a seventh aspect of the present invention, in the heat exchanger according to the fifth or sixth aspect, the distance between the position and the position where the height of the leeward side end of the flat tube starts to gradually decrease toward the tip. (L) is L ≧ 1 with respect to the fin height (Fh)
Since it is set to / 2Fh, the condensed water between the fins and the passing air can be smoothly discharged to the outside through the clearance.

According to an eighth aspect of the present invention, in the heat exchanger according to any one of the fifth to seventh aspects, the clearance width (W) between the tip of the flat tube and the end of the fin and the fin pitch (Fp). Is set so that W ≧ 1/2 Fp, the condensed water led from between the fins is discharged from the clearance without stagnating in the clearance,
As a result, stagnation of dew condensation water between the fins can be significantly reduced.

According to a ninth aspect of the present invention, in the heat exchanger according to any one of the first to eighth aspects, since the notch is provided at the windward end of the fin, the fin is accumulated at the leeward end. Since the dew condensation water that is generated is guided to the clearance through this cut, it is possible to prevent a large amount of dew condensation water from stagnating at the leeward side end portions of the fins, and to prevent an increase in ventilation resistance between the fins due to the dew condensation water.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a heat exchanger such as an evaporator of a vehicle air conditioner. In the heat exchanger 1, a plurality of flat tubes 2 through which a refrigerant flows and corrugated fins 3 that exchange heat with air are stacked, and long tubular header tanks 4 are arranged at the upper and lower ends of these flat tubes 2. . In this heat exchanger 1, the heat exchange medium supplied to one of the header tanks 4 passes through the inside of the flat tube 2 and is heat-exchanged with the outside air during the passage, reaches the other header tank 4, and the heat is exchanged. Ejected from the exchanger.

Details of the flat tube 2 and the corrugated fins 3 will be described with reference to FIGS. 2A shows a partially enlarged plan view of the flat tube 2 and the corrugated fins 3, and FIG. 2B shows a view of FIG. 2A viewed from the direction of arrow A. FIG. 3 shows a partial perspective view of the flat tube 2 and the corrugated fin 3.

The flat tube 2 is manufactured by extrusion molding,
The leeward end 2a is formed so that it becomes thinner toward the tip. A plurality of refrigerant passages 5 are provided inside thereof. The condensed water F generated in the corrugated fin 3 is
As shown by the slanted lines in FIG. 2, the corrugated fins 3 are concentrated and stagnant in the portion of the leeward side end 3a that is bent into a substantially U shape. Therefore, the ventilation area between the fins 6 is reduced and the ventilation resistance tends to increase. However, in this embodiment, the clearance 7 is provided between the flat tubes 2 and the fins 3.
Since the air between the fins 6 is provided, the air between the fins 6 is guided from the fins 3 to the clearance 7 and is discharged to the outside from there, as shown by the arrow in FIG. Therefore, even if the dew condensation water F is stagnant on the leeward side end 3a of the fin 3, it is possible to suppress an increase in ventilation resistance. In addition, the dew condensation water F itself is also the clearance 7
Since the amount of accumulated dew condensation water F itself is also reduced, the increase in ventilation resistance due to dew condensation water can be suppressed.

In particular, the leeward end 2a of the flat tube 2
Is formed so as to smoothly incline from the portion in contact with the fin 3 to the central portion away from the fin 3, and the width (W) of the clearance 7 is gradually increased. The surface functions as a delivery guide for the condensed water F or air passing through the clearance 7, and these can be quickly discharged from the clearance 7.

As shown in FIG. 3, in the leeward side end 2a of the flat tube 2, the distance (L) between the tip end and the position where the flat tube 2 starts to incline to form the clearance 7 is relative to the fin height (Fh). Therefore, L ≧ 1 / 2Fh. That is, the position where the inclination starts is the leeward end 3 of the fin 3.
In order for the air between the fins 6 to be guided to the clearance 7 from between the fins 6 even if the condensed water F collects in a,
It is set within the above range.

The clearance width (W) between the tip end of the flat tube 2 and the leeward end 3a of the fin 3 and the fin pitch (Fp) are set to W ≧ 1 / 2Fp. If the width (W) is too small, the condensed water F guided to the clearance 7 may not be discharged from the clearance 7 and may become stagnant. However, by setting the width (W) in the above range, the clearance outlet It is possible to prevent stagnation of dew condensation water.

FIG. 4 relates to the second embodiment and shows a view similar to FIG. Only parts different from the first embodiment will be described. In the second embodiment, the notch 8 is provided at the leeward end 22a of the fin 22. The condensed water F accumulated in the space 6 between the fins is guided to the clearance 7 through the notch 8, so that the condensed water F is less likely to be accumulated in the wind lower end portions 22a of the fins 22 and the ventilation resistance is extremely small. The length of the cut 8 is substantially equal to the length (L) of the clearance 7.

FIG. 5 relates to the third embodiment, and is one in which one plate material is bent by roll forming to form a flat tube 31. That is, both ends of the plate material are bent in a substantially U shape, but are abutted at an intermediate portion, both end parts are further bent inwardly, abutted on the inner surface, and then further bent at a substantially right angle along the inner surface to form the flat tube 31. Is forming. In the third embodiment, the leeward end portion 31a is provided so that the clearance 7 is formed at the leeward end portion when the U-shaped bending is performed.
Bend it into a nearly V-shape. In the third embodiment, the windward end portion is also bent in the same manner, and the flat tube 31 has a left-right symmetrical system to facilitate the assembling work.

The clearance 7 is formed by the flat tube 2,
The flat tubes may be symmetrically provided not only on the leeward side end portions of 21 and 31 but also on the leeward side end portions to facilitate assembly. Alternatively, the clearance may be provided only on the leeward side end, and the leeward side end may be the same as in the conventional case, and a large refrigerant passage in the flat tube may be secured. Further, the inclination angles of the inclined surfaces for forming the clearance may be the same in the vertical direction, or may be different in the vertical direction in consideration of dew condensation water and air resistance. It is also possible to make this inclination angle inclined to the left and right (longitudinal direction of the flat tube) so that the dew condensation water in this clearance can easily flow to one header tank side and improve the drainability of the dew condensation water. Is.

[0027]

According to the present invention, a plurality of flat tubes in which a refrigerant flows and corrugated fins that exchange heat with air are alternately laminated and arranged, and the refrigerant flows in the flat tube in the longitudinal direction of the flat tube. In a heat exchanger in which air flows between the fins in a direction orthogonal to the flow direction of the refrigerant and the stacking direction of the flat tubes and the fins, the leeward side end of the flat tubes is composed of one member, and the leeward side Since a predetermined clearance is provided between the end and the end of the fin facing the end, dew condensation water generated between the fins can be quickly discharged through the clearance.
Ventilation resistance and flying water can be reduced.

In the case where the height of the leeward side end of the flat tube is set to gradually decrease toward the tip and a clearance is formed, condensed water and air can flow out through this clearance. Further, it is possible to suppress an increase in ventilation resistance and effectively prevent flying water and the like.

[Brief description of drawings]

FIG. 1 shows a heat exchanger to which the present invention is applied.

2 is a partially enlarged view of the heat exchanger of FIG.
2A is an enlarged partial sectional view of a flat tube and fins, and FIG. 2B is a view as viewed from the arrow A of FIG. 2A.

FIG. 3 is a diagram illustrating a dimensional relationship between the flat tubes and fins of FIG.

FIG. 4 is a view similar to FIG. 3 relating to the second embodiment.

FIG. 5 is a partial view of a flat tube and fins according to the third embodiment.

FIG. 6 shows a conventional heat exchanger.

FIG. 7 shows a partial view of the heat exchanger of FIG. 6, FIG. 7 (a) shows a partial view of a flat tube and fins, and FIG. 7 (b) shows a view of arrow A in FIG. 7 (a). .

FIG. 8 shows still another conventional structure, which is similar to FIG. 7.

[Explanation of symbols]

1 heat exchanger 2 Flat tube 3 corrugated fins 4 header tank 5 Refrigerant passage Between 6 fins 7 clearance 8 notches F condensed water L distance W clearance width Fh fin height Fp fin pitch

Claims (9)

[Claims] 1. A plurality of flat tubes in which a refrigerant flows and corrugated fins that exchange heat with air are alternately laminated and arranged, and the refrigerant flows in the flat tubes in the longitudinal direction of the flat tubes. And a heat exchanger in which air flows between the fins in a direction orthogonal to the stacking direction of the flat tubes and the fins, wherein the leeward side end of the flat tubes is composed of one member, and the leeward side ends And a predetermined clearance is provided between the end portion and the end portion of the fin facing the end portion. 2. The heat exchanger according to claim 1, wherein the height of the leeward side end of the flat tube is set lower than the height of other portions. 3. The heat exchanger according to claim 1, wherein the flat tube is formed by bending one thin plate by roll forming. 4. The heat exchanger according to claim 1, wherein the flat tube is integrally formed by extrusion molding. 5. The heat exchanger according to claim 1, wherein the height of the leeward side end of the flat tube is set to gradually decrease toward the tip. And 6. The heat exchanger according to claim 5, wherein the leeward end portion of the flat tube is tapered from both flat surface portions in contact with the fins on both sides toward an intermediate portion separated from the fins. It is set to. 7. The heat exchanger according to claim 5, wherein the distance (L) between the position where the height of the leeward side end of the flat tube starts to gradually decrease toward the tip and the tip (F) is the fin. The height (Fh) is set so that L ≧ 1 / 2Fh. 8. The heat exchanger according to claim 5, wherein the clearance width (W) between the tip of the flat tube and the end of the fin and the fin pitch (Fp) are W ≧ 1 / 2F
It is characterized in that it is set to be p. 9. The heat exchanger according to any one of claims 1 to 8, characterized in that a notch is provided in the wind lower end portion of the fin.