JP2010014329A - Heat exchanger - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heat exchanger improved in dew condensate draining performance. <P>SOLUTION: A plane part 11a of a flat tube 11 in the heat exchanger 10 inclines to be low in height toward the downstream side of air flow. An upstream side end face 12e and a downstream side end face 12f of air flow of a corrugated fin 12 are almost parallel with a vertical direction. The dew condensate produced on the surface of the corrugated fin 12 and on the surface of the flat tube 11 flows along the inclined plane part 11a of the flat tube 11 and moves to the upper part of the downstream side end face 12f of the corrugated fin 12 below. Since the downstream side end face 12f stands almost vertically, the fall speed of the dew condensate is fast to improve drainage. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a heat exchanger provided with flat tubes and fins.

  Conventionally, a heat exchanger in which a flat portion of a flat tube is horizontal and fins are disposed between the flat portion and the flat portion has been widely used. In such a heat exchanger, since the fins are divided by the flat tube, the condensed water stays and becomes ventilation resistance. In order to eliminate the retention of the condensed water, a heat exchanger is provided in which a protrusion is protruded from the end of the fin to the downstream side of the air flow, and a notch is provided in the protrusion (see Patent Document 1). ). According to the heat exchanger disclosed in Patent Document 1, the generated condensed water is pushed by the air flow, gathers on the downstream side, and falls downward through the notch.

However, in the heat exchanger as described above, the condensed water falls from the notch when the condensed water has grown to a size that can be dropped by its own weight, and the condensed water periodically enters the heat exchanger. It may stay, and the drainage of condensed water is low. In addition, in a situation where further downsizing of the heat exchanger is progressing, the downsizing of the heat exchanger is likely to reduce the drainability of the heat exchanger with respect to the dew condensation water, so further improvement in drainage is required. .
Japanese Utility Model Publication No. 63-6632

  The subject of this invention is providing the heat exchanger which improved the drainage property with respect to dew condensation water.

  The heat exchanger according to the first invention includes a flat tube and a fin. The flat tubes are arranged in a plurality of stages in a state where the plane portion is directed in the vertical direction. The fins are arranged in a state of being bent into a waveform in a ventilation space sandwiched between upper and lower adjacent flat tubes. The flat portion of the flat tube is inclined so that its height decreases toward the downstream side of the air flow passing through the ventilation space. The upstream end surface and the downstream end surface of the fin air flow are substantially parallel to the vertical direction.

  In this heat exchanger, the condensed water generated on the fin surface and the flat tube surface flows down along the flat portion of the inclined flat tube. And when dew condensation water is transmitted to the upper part of the fin end surface of the lower part, since the end surface of a fin stands substantially vertical, the speed at which dew condensation water falls will become faster than a conventional product, and water drainage will become still better. Furthermore, compared with the conventional product in which the inclined flat portion of the flat tube and the end face of the fin are perpendicular, the contact area between the flat portion and the fin is widened, so that the heat exchange performance is improved.

  The heat exchanger according to the second aspect of the present invention is the heat exchanger according to the first aspect of the present invention, wherein the end face when the fin is expanded to a flat plate state before being bent into a corrugated shape is sheared zigzag.

  In this heat exchanger, the end face of the fin after bending is substantially parallel to the vertical direction when the fin is disposed in the ventilation space. As a result, fin processing is easy and productivity is increased.

  A heat exchanger according to a third aspect of the present invention is the heat exchanger according to the first aspect of the present invention, wherein a portion that is to come into contact with the flat portion of the flat tube when the fin is bent into a corrugated shape is bent into a trapezoidal shape. .

  In this heat exchanger, the end face of the fin after bending is substantially parallel to the vertical direction when the fin is disposed in the ventilation space. As a result, fin processing is easy and productivity is increased.

  A heat exchanger according to a fourth aspect of the present invention is the heat exchanger according to any one of the first to third aspects of the present invention, further comprising auxiliary fins that come into contact with the flat tube and / or the fins. The auxiliary fin protrudes from the ventilation space to the downstream side of the air flow.

  In this heat exchanger, the dew condensation water generated on the fin surface and the flat tube surface flows downward through the auxiliary fins, so that drainage is further improved.

  In the heat exchanger according to the first aspect of the invention, the speed at which the condensed water descends is fast, and the drainage is good. Furthermore, the contact area between the flat portion and the fin is wide, and heat exchange performance is improved.

  In the heat exchanger according to the second or third invention, the fins are easily processed and the productivity is high.

  In the heat exchanger according to the fourth aspect of the invention, the dew condensation water generated on the fin surface and the flat tube surface flows downward through the auxiliary fin, so that drainage is further improved.

  Embodiments of the present invention will be described below with reference to the drawings. The following embodiments are specific examples of the present invention and do not limit the technical scope of the present invention.

[First Embodiment]
<Configuration of heat exchanger 10>
FIG. 1 is a front view of a heat exchanger according to the first embodiment of the present invention, and FIG. 2 is a partial cross-sectional view of the heat exchanger of FIG. 1 cut along a plane perpendicular to the longitudinal direction of the flat tube. It is. In FIG. 1, the heat exchanger 10 includes a flat tube 11, a corrugated fin 12, and a header 15.

(Flat tube 11)
In FIG. 2, the flat tube 11 is formed from aluminum or an aluminum alloy, and has a flat portion 11a serving as a heat transfer surface and a plurality of refrigerant flow paths 11b through which a refrigerant flows. The flat tubes 11 are arranged in a plurality of stages in a state in which the flat surface portion 11a is directed upward and downward, and the flat surface portion 11a is inclined so that the height decreases toward the downstream side of the air flow A.

(Waveform fin 12)
FIG. 3 is a perspective view of a corrugated fin. In FIG. 3, corrugated fins 12 are fins made of aluminum or aluminum alloy that are bent into corrugations. The corrugated fins 12 are arranged in a ventilation space sandwiched between upper and lower flat tubes 11, and bent portions 12 b serving as valley portions and mountain portions are in contact with the flat portions 11 a of the flat tubes 11 (see FIG. 1). . The bent portion 12b and the flat portion 11a are brazed and welded.

  As shown in FIG. 2, the heat transfer surface 12 a is a portion that exchanges heat with the air flow A that passes through the ventilation space, and a louver 12 c for efficiently performing heat exchange is formed. Louver 12c forms an opening penetrating from one surface of heat transfer surface 12a to the other surface. For convenience of explanation, in the front view of FIG. 2, the front side of the heat transfer surface 12a is referred to as a “first surface” and the back side is referred to as a “second surface”. The louver 12c group located upstream from the center of the heat transfer surface 12a is inclined so that the air flow flows from the second surface to the first surface, and the louver 12c located downstream from the center of the heat transfer surface 12a. The group is tilted so that the airflow flows from the first surface to the second surface.

  In the corrugated fin 12, the upstream end face 12e located on the upstream side of the air flow A and the downstream end face 12f located on the downstream side are substantially parallel to the vertical direction. In this embodiment, when the corrugated fin 12 is placed on the flat surface portion 11a of the inclined flat tube 11, the corrugated fin 12 is arranged such that the upstream end surface 12e and the downstream end surface 12f are substantially parallel to the vertical direction. Before the material is bent into a waveform, the material is subjected to predetermined processing.

  FIG. 4 is a development view of corrugated fins. In FIG. 4, the expanded corrugated fins 12 are arranged such that the parallelogram heat transfer surfaces 12a are spaced at a constant interval in a direction perpendicular to the long sides, and the short sides of the adjacent heat transfer surfaces 12a are not parallel to each other. It is out. As a result, a rectangular region is formed between the adjacent heat transfer surfaces 12 a, and this long-diameter region is the bent portion 12 b of the corrugated fin 12.

  Since the short side of the parallelogram heat transfer surface 12 a is the upstream end surface 12 e or the downstream end surface 12 f, the upstream end surface 12 e or the downstream end surface 12 f is zigzag along the longitudinal direction of the corrugated fins 12. As a result, when the corrugated fin 12 is bent, the upstream end surface 12e and the downstream end surface 12f are inclined with respect to the bent portion 12b. When the bent portion 12b is placed on the flat surface portion 11a of the inclined flat tube 11, the upstream end surface 12e and the downstream end surface 12f are parallel to the vertical direction.

(Header 15)
In FIG. 1, the header 15 is connected to both ends of flat tubes 11 arranged in a plurality of stages in the vertical direction. For convenience of explanation, the header on the right side in FIG. 1 is called “first header 151”, and the header on the left side is called “second header 152”. The first header 151 and the second header 152 have a function of supporting the flat tube 11, a function of guiding the refrigerant to the refrigerant flow path 11b of the flat pipe 11, and a function of collecting the refrigerant that has come out of the refrigerant flow path 11b. Have.

(Refrigerant flow)
In FIG. 1, the refrigerant flowing from the inlet 151 a of the first header 151 is distributed almost evenly to the respective refrigerant flow paths 11 b of the uppermost flat tube 11 and flows toward the second header 152. The refrigerant reaching the second header 152 is evenly distributed to the respective refrigerant flow paths 11b of the second-stage flat tube 11 and flows toward the first header 151. Thereafter, the refrigerant in the odd-numbered flat tubes 11 flows toward the second header 152, and the refrigerant in the even-numbered flat tubes 11 flows toward the first header 151. And the refrigerant | coolant in the flat tube 11 of the lowest level and the even-numbered level flows toward the 1st header 151, gathers at the 1st header 151, and flows out from the exit 151b.

  In addition, how the refrigerant flows changes depending on the application or the degree of pressure loss of the refrigerant. For example, the pressure loss of the refrigerant may be suppressed by allowing the refrigerant to flow in the same direction in the plurality of flat tubes 11 at the same time. Hereinafter, another flow of the refrigerant will be described with reference to FIG. 1 again.

  First, the refrigerant flowing from the inlet 151 a of the first header 151 is distributed almost evenly to the respective refrigerant flow paths 11 b of the uppermost and second flat tubes 11 and flows toward the second header 152. The refrigerant reaching the second header 152 is evenly distributed to the refrigerant flow paths 11b of the third and fourth flat tubes 11 and flows toward the first header 151. The refrigerant reaching the first header 151 is distributed almost evenly to the refrigerant flow paths 11 b of the fifth and sixth flat tubes 11 and flows toward the second header 152. The refrigerant that has reached the second header 152 is distributed almost evenly to the refrigerant flow paths 11 b of the seventh and eighth flat tubes 11 and flows toward the header 151. Then, the refrigerant collected at the first header 151 flows out from the outlet 151b. As a result, the flow rate of the refrigerant passing through the refrigerant flow path 11b is lowered, and the pressure loss of the refrigerant is reduced.

  When the heat exchanger 10 functions as an evaporator, the refrigerant flowing through the refrigerant flow path 11b absorbs heat from the air flow flowing through the ventilation space via the corrugated fins 12. When the heat exchanger 10 functions as a condenser, the refrigerant flowing through the refrigerant flow path 11b radiates heat to the air flow flowing through the ventilation space via the corrugated fins 12.

(Flow of condensed water)
In general, when the flat tubes 11 are arranged with the flat portion 11a facing up and down, drainage of the surface of the heat exchanger is poor, and when used as an evaporator, the accumulated condensed water becomes resistance to air flow and heat exchange performance is improved. May decrease. However, in the heat exchanger 10 of this embodiment, as shown in FIG. 2, since the flat part 11a of the flat tube 11 inclines, dew condensation water does not stay. Hereinafter, the flow of condensed water will be described with reference to the drawings.

  In FIG. 2, the dew condensation water W generated on the heat transfer surface 12a of the corrugated fin 12 is pushed by the air flow A and moves downstream while descending the heat transfer surface 12a by gravity. The condensed water that has fallen to the flat part 11a of the flat tube 11 and the condensed water generated in the flat part 11a move downstream along the inclination of the flat part 11a. Condensed water descending to the bent part 12b (valley part) of the corrugated fin 12 also moves downstream along the inclination because the bent part 12b is also inclined in the same manner as the flat part 11a. Moreover, the dew condensation water which penetrate | invaded into the clearance gap between the trough part of the corrugated fin 12 and the plane part 11a of the flat tube 11 moves downstream along the inclination of the plane part 11a by the capillary phenomenon by the clearance gap.

  Condensed water that has reached the downstream end face 12 f of the corrugated fin 12 moves from the downstream end of the flat tube 11 to the downstream end face 12 f of the corrugated fin 12 positioned below by the action of gravity and airflow A. And it moves to the downstream end surface 12f of the corrugated fin 12 located further downward.

<Features>
(1)
In the heat exchanger 10, the flat portion 11a of the flat tube 11 is inclined so that its height decreases as it becomes downstream of the air flow. The upstream end surface 12e and the downstream end surface 12f of the airflow of the corrugated fins 12 are substantially parallel to the vertical direction. The condensed water generated on the surface of the corrugated fin 12 and the surface of the flat tube 11 flows along the flat portion 11a of the inclined flat tube 11 and moves to the upper part of the downstream end face 12f of the corrugated fin 12 below. Since the downstream end face 12f stands substantially vertically, the dew rate of condensed water is high and the drainage is improved. In addition, compared with the conventional product in which the inclined flat surface portion 11a of the flat tube 11 and the end surface of the corrugated fin 12 are perpendicular, the contact area between the flat surface portion 11a and the corrugated fin 12 is widened, so that heat exchange is performed. Performance is improved.

(2)
In the heat exchanger 10, since the end face when the corrugated fin 12 is expanded is zigzag, the upstream end face 12e and the downstream end face 12f of the corrugated fin 12 after being bent are arranged in the ventilation space. Sometimes it is almost parallel to the vertical direction. As a result, the processing of the corrugated fin 12 is easier and the productivity is higher than the method of bending the corrugated fin into a corrugated shape and then shearing so that the end portion is inclined with respect to the bent portion.

<Modification>
In the first embodiment, when the corrugated fin 12 is deployed, the end face when the corrugated fin 12 is unfolded is zigzag. Although it is made to become substantially parallel to a direction, it is not limited to this. For example, even if the end face when the corrugated fin is deployed is straight, it may be bent so that the upstream end face and the downstream end face are inclined with respect to the bent portion after the bending. Hereinafter, it demonstrates using drawing. In addition, the same member as the said embodiment is used except a waveform fin.

(Waveform 112)
FIG. 5 is a perspective view of a corrugated fin of a heat exchanger according to a modification. In FIG. 5, corrugated fins 112 are aluminum or aluminum alloy fins bent into corrugations. The heat transfer surface 112a is a portion that exchanges heat with the air passing through the ventilation space, and a louver 112c for efficiently exchanging heat is formed.

  In the modified example, when the corrugated fin 112 is disposed in the ventilation space sandwiched between the flat tubes 11 adjacent vertically, the corrugated fin 112 is arranged so that the upstream end surface 112e and the downstream end surface 112f are substantially parallel to the vertical direction. At the stage where the material of the fin 112 is bent into a corrugated shape, the bent portion 112b is bent into a trapezoidal shape.

  FIG. 6 is a development view of corrugated fins according to a modification. In FIG. 6, the expanded corrugated fins 112 are arranged such that the parallelogram heat transfer surfaces 112a are straight in the direction of the short side at regular intervals, and the adjacent heat transfer surfaces 112a are not parallel to each other. As a result, a trapezoid is formed between adjacent heat transfer surfaces 112 a, and this trapezoid is the bent portion 112 b of the corrugated fin 112.

  Since the short side of the parallelogram heat transfer surface 112a is the upstream end surface 112e or the downstream end surface 112f, when the corrugated fin 112 is bent while forming the trapezoidal bent portion 112b, the upstream end surface 112e and the downstream side The side end face 112f is inclined with respect to the bent portion 112b. When the bent portion 112b is placed on the flat surface portion 11a of the inclined flat tube 11, the upstream end surface 112e and the downstream end surface 112f are parallel to the vertical direction. As a result, the processing of the corrugated fin 112 is easier and the productivity is higher than the method of bending the corrugated fin into a corrugated shape and then shearing so that the end portion is inclined with respect to the bent portion.

[Second Embodiment]
In the first embodiment, the flat tube 11 is inclined and the upstream end surface 12e and the downstream end surface 12f of the corrugated fin 12 are parallel to the vertical direction so that the condensed water is removed. In order to improve, an auxiliary fin may be arranged on the downstream side of the air flow. The second embodiment will be described below with reference to the drawings. In addition, the same name and the same code | symbol are provided to the same member as 1st Embodiment, and description is abbreviate | omitted.

(Auxiliary fin 13)
FIG. 7 is a partial cross-sectional view when the heat exchanger according to the second embodiment is cut along a plane perpendicular to the longitudinal direction of the flat tube. In FIG. 7, the heat exchanger 10 includes auxiliary fins 13 that contact the flat tubes 11 and the corrugated fins 12. The auxiliary fins 13 protrude from the ventilation space to the downstream side of the air flow A. The auxiliary fin 13 may be in contact with either the flat tube 11 or the corrugated fin 12.

(Flow of condensed water)
As shown in FIG. 7, the dew condensation water W generated on the heat transfer surface 12a of the corrugated fin 12 is pushed by the air flow A and moves downstream while descending the heat transfer surface 12a by gravity. The condensed water that has fallen to the flat part 11a of the flat tube 11 and the condensed water generated in the flat part 11a move downstream along the inclination of the flat part 11a. Condensed water descending to the bent part 12b (valley part) of the corrugated fin 12 also moves downstream along the inclination because the bent part 12b is also inclined in the same manner as the flat part 11a. Moreover, the dew condensation water which penetrate | invaded into the clearance gap between the trough part of the corrugated fin 12 and the plane part 11a of the flat tube 11 moves downstream along the inclination of the plane part 11a by the capillary phenomenon by the clearance gap.

  Condensed water that has reached the downstream end face 12 f of the corrugated fin 12 moves to the auxiliary fin 13 by the action of gravity and airflow A, and moves downward along the auxiliary fin 13. As a result, drainage is further improved as compared with the case without the auxiliary fins 13.

  As described above, the heat exchanger according to the present invention is useful for a heat exchanger of an air conditioner and a radiator of an automobile because it can drain the condensed water even when the flat tubes are arranged in a plurality of stages in the vertical direction. is there.

The front view of the heat exchanger which concerns on 1st Embodiment of this invention. The fragmentary sectional view when the heat exchanger of FIG. 1 is cut along a plane perpendicular to the longitudinal direction of the flat tube. The perspective view of a corrugated fin. FIG. The perspective view of the corrugated fin of the heat exchanger which concerns on a modification. The expanded view of the corrugated fin which concerns on a modification. The fragmentary sectional view when the heat exchanger which concerns on 2nd Embodiment is cut | disconnected by the plane perpendicular | vertical to the longitudinal direction of a flat tube.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Heat exchanger 11 Flat tube 11a Plane | planar part 12,112 Corrugated fin 12e, 112e Upstream side end surface 12f, 112f Downstream side end surface 13 Auxiliary fin 112b Bending part (part which is to touch the flat part of a flat tube)

Claims (4)

Flat tubes (11) arranged in a plurality of stages in a state where the flat surface portion (11a) is directed in the vertical direction;
Fins (12, 112) disposed in a state of being bent into a wave shape in a ventilation space sandwiched between the flat tubes (11) adjacent vertically.
With
The flat portion (11a) of the flat tube (11) is inclined so that its height decreases toward the downstream side of the airflow passing through the ventilation space,
The upstream end face (12e, 112e) and the downstream end face (12f, 112f) of the air flow of the fin (12, 112) are substantially parallel to the vertical direction.
Heat exchanger (10). The end face when the fin (12) is expanded into a flat plate state before being bent into the corrugated shape is sheared zigzag,
The heat exchanger (10) according to claim 1. A portion (112b) scheduled to contact the flat portion (11a) of the flat tube (11) when the fin (112) is bent into the corrugated shape is bent into a trapezoidal shape,
The heat exchanger (10) according to claim 1. An auxiliary fin (13) in contact with the flat tube (11) and / or the fin (12, 112);
The auxiliary fin (13) protrudes from the ventilation space to the downstream side of the air flow,
The heat exchanger (10) according to any one of claims 1 to 3.

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