JP5020886B2 - Heat exchanger - Google Patents

Description

  The present invention relates to a parallel flow type heat exchanger.

  A parallel flow type heat exchange in which a plurality of flat tubes are arranged between two header pipes so that a refrigerant passage inside the flat tubes communicates with the header pipe, and fins such as corrugated fins are arranged between the flat tubes. The equipment is widely used in outdoor units of car air conditioners and building air conditioners. An example of this can be seen in US Pat.

  An example of a conventional parallel flow heat exchanger is shown in FIG. In the heat exchanger 1, two horizontal header pipes 2 and 3 are arranged in parallel with an interval in the vertical direction, and a plurality of vertical flat tubes 4 are arranged between the header pipes 2 and 3 at a predetermined pitch. The flat tube 4 is an elongated molded product obtained by extruding a metal having good heat conductivity such as aluminum, and a refrigerant passage 5 through which a refrigerant flows is formed inside. Since the flat tube 4 is disposed so that the extrusion molding direction is vertical, the refrigerant flow direction of the refrigerant passage 5 is also vertical. Each refrigerant passage 5 communicates with the inside of the header pipes 2 and 3. In FIG. 11, the upper side of the paper is the upper side in the vertical direction, the lower side of the paper is the lower side in the vertical direction, and a plurality of flat tubes 4 are vertically arranged between the upper header pipe 2 and the lower header pipe 3. The configuration is arranged at a predetermined pitch.

  The header pipes 2 and 3 and the flat tube 4 are fixed by welding. A plurality of refrigerant passages 5 are arranged in the depth direction of the figure, and therefore the flat tube 4 has a cross section like a harmonica. Corrugated fins 6 are disposed between the flat tubes 4. The flat tube 4 and the corrugated fin 6 are fixed by welding, brazing or the like. In addition to the flat tube 4, the header pipes 2 and 3 and the corrugated fin 6 are also made of a metal having good heat conduction.

Since many flat tubes 4 are provided between the header pipes 2 and 3 and corrugated fins 6 are provided between the flat tubes 4, the heat exchanger 1 has a large heat radiation (heat absorption) area, and efficiently exchanges heat. It can be performed. A refrigerant inlet 7 is provided at one end of the lower header pipe (sometimes referred to as a lower header pipe), and a refrigerant flow is provided at one end of the upper header pipe (sometimes referred to as an upper header pipe) 2. A refrigerant outlet 8 is provided at a position diagonal to the inlet 7.
JP-A-6-147785

  When a parallel flow type heat exchanger is used as an evaporator, a low-temperature refrigerant flows through the refrigerant passage 5 and the surface temperature of the flat tubes 4 and the corrugated fins 6 decreases. Thereby, the phenomenon (frosting phenomenon) that the water | moisture content in air adheres as a frost on the surface of the flat tube 4 or the corrugated fin 6 occurs. When frost formation occurs, the transfer of cold heat from the flat tube 4 and the corrugated fin 6 to air deteriorates, and the gap between the corrugated fins 6 is narrowed by frost, making it difficult for the air to flow. descend. For this reason, in a parallel flow type heat exchanger, how to deal with frost formation is always a technical problem.

  This invention is made | formed in view of said point, and it aims at making a parallel flow type heat exchanger into the structure which is not connected with the fall of heat exchange efficiency even if frost formation arises.

In order to achieve the above object, the present invention provides a plurality of header pipes arranged in parallel at intervals, and a plurality of refrigerant pipes arranged between the plurality of header pipes, and having refrigerant passages provided inside the header pipes. In the heat exchanger comprising a flat tube communicated with the corrugated fin and a corrugated fin disposed between the flat tubes, the corrugated fin is provided with a cut-out portion at the windward end of the airflow passing through the corrugated fin. The cut portion is provided at a bending portion of the corrugated fin, and has a depth at which contact between the flat tube and the corrugated fin starts or reaches the leeward side beyond the portion. It is a feature.

  According to this configuration, the length of the edge of the windward end portion of the corrugated fin is extended by providing the cut portion at the windward end portion of the corrugated fin. The edge of the windward end of the corrugated fin is a place where frost formation is particularly likely to occur due to the leading edge effect. If the excision part is provided, the edge of the excision part is also frosted, and the amount of frost formation at the windward end is increased. For this reason, time until the clearance gap between corrugated fins is narrowed by frost and it becomes difficult to flow air can be made longer than the case where an excision part is not provided. In other words, the time until the heat exchanger is clogged due to frost formation can be increased. Thus, since the air volume fall of the air which passes a heat exchanger can be suppressed, it becomes possible to maintain the heat exchange efficiency as the whole heat exchanger over a long period of time.

Since the excision part is provided at a bending portion of the corrugated fin, the work of forming the excision part by cutting or cutting can be easily performed. Moreover, since the said cut part is provided with the depth which reaches the leeward side beyond the location where the contact of the said flat tube and the said corrugated fin starts, the deep and long cut part can be obtained .

  In the heat exchanger having the above-described configuration, it is preferable that the cut portion is provided in a plane portion intermediate between the folded portion and the folded portion of the corrugated fin.

  With such a configuration, the number of cut portions can be increased, and the length of the edge of the windward end portion of the corrugated fin can be further expanded.

  In the heat exchanger configured as described above, it is preferable that the windward end portion of the corrugated fin protrudes further to the windward side than the windward end portion of the flat tube, and the cut portion is provided in the protruding portion.

  With such a configuration, frost is formed outside the flat tubes, so that the flat tubes cannot be narrowed by frost.

  According to the present invention, by extending the edge of the windward end of the corrugated fin, it is possible to lengthen the time until the gap between the corrugated fin is narrowed by frost and the air does not flow easily. The heat exchange efficiency can be maintained over a long period of time.

  A first embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is a partial perspective view of a parallel flow type heat exchanger, and FIG. 2 is a vertical sectional view of the parallel flow type heat exchanger. The cross-sectional direction in FIG. 2 is perpendicular to the cross-sectional direction in FIG. Elements that are functionally common to the heat exchanger having the conventional structure shown in FIG. 6 are denoted by the same reference numerals as those used in FIG. The same applies to the second and following embodiments.

  The corrugated fin 6 of the heat exchanger 1 has a predetermined length on the windward end of the airflow passing therethrough (indicated by the arrow in FIG. 1) on the windward side of the windward end of the flat tube 4. It has a protruding shape. A cut-out portion 9 is provided at a bent portion of the ridge of the protruding portion 6a of the corrugated fin 6, that is, a left or right U-turn portion as viewed from the windward side. The excision part 9 is an isosceles triangular notch whose apex is directed toward the flat tube 4 and has a depth that reaches a position where contact between the flat tube 4 and the corrugated fin 6 begins (where welding or brazing starts). It is prepared. The excision part 9 may further reach the leeward side beyond the point where the contact between the flat tube 4 and the corrugated fin 6 starts.

  Thus, by providing the cut portion 9 at the windward end of the corrugated fin 6, the length of the edge of the windward end of the corrugated fin 6 is extended. This edge portion is a portion where frost formation is particularly likely to occur due to the leading edge effect. If the excision part 9 is provided, the edge of the excision part 9 is also frosted, and the amount of frost formation at the windward end is increased. For this reason, the time until the gap between the corrugated fins 6 is narrowed by frost and the air hardly flows can be made longer than when the cut portion 9 is not provided. In other words, the time until the heat exchanger 1 is clogged by frost formation can be increased. Thus, since the air volume drop of the air which passes the heat exchanger 1 can be suppressed, it becomes possible to maintain the heat exchange efficiency as the heat exchanger 1 whole over a long period of time.

  The windward end portion of the corrugated fin 6 protrudes further to the windward side than the windward end portion of the flat tube 4, and the cut portion 9 is provided in the protruding portion 6 a, so that frost is formed between the flat tubes 4. It occurs on the outside, and the space between the flat tubes 4 is not narrowed by frost. Moreover, since the cutting part 9 is provided in the bending part of the corrugated fin 6, the work of forming the cutting part by cutting or cutting can be easily performed. And since the excision part 9 is provided with the location which the contact of the flat tube 4 and the corrugated fin 6 starts, or the depth which reaches the leeward side beyond the location, the deep excision part 9 with a long edge can be obtained.

  FIG. 3 shows a second embodiment of the present invention. FIG. 3 is a vertical sectional view similar to FIG. 2 of the parallel flow type heat exchanger.

  The second embodiment differs from the first embodiment in the shape of the cut portion 9. That is, in the second embodiment, the cut portion 9 is formed with a slit having a uniform width. This shape can further extend the length of the edge of the windward end of the corrugated fin 6 than the isosceles triangle of the first embodiment.

  FIG. 4 shows a third embodiment of the present invention. FIG. 4 is a partial perspective view of a parallel flow type heat exchanger.

  In the third embodiment, the following configuration is added to the first embodiment. That is, in the third embodiment, the cut portion 10 is provided also in the plane portion between the folding portion and the folding portion of the corrugated fin 6. The cut portions 10 are isosceles triangles having a wide apex angle, and three cut portions 10 are arranged on one plane portion.

  According to the configuration of the third embodiment, the number of cut portions can be increased, and the length of the edge of the windward end portion of the corrugated fin 6 can be further expanded. Note that the shape of the cut portion 10 is an isosceles triangle with a wide apex angle is merely an example, and other shapes (for example, a rectangle or a semicircle) can be employed. In addition, the number of the cut portions 10 per one plane portion is three only, and other numbers may be used. Further, the excision part 9 can be eliminated and only the excision part 10 can be provided.

  FIG. 5 shows a fourth embodiment of the present invention. FIG. 5 is a partial horizontal sectional view of a parallel flow type heat exchanger.

  The fourth embodiment is obtained by adding the following modifications to the third embodiment. That is, in the third embodiment, the windward end portion of the corrugated fin 6 protrudes further to the windward side than the windward end portion of the flat tube 4, and the cut portion 9 and the cut portion 10 are provided in the protruding portion 6a. In the fourth embodiment, the cut portion 9 and the cut portion 10 are provided without forming such a protruding portion 6a. Even in this configuration, the length of the edge of the windward end portion of the corrugated fin 6 is extended, and the time until the gap between the corrugated fins 6 is narrowed by frost and the air does not flow easily is not provided. It can be longer than the case. The excision part 9 can be eliminated and only the excision part 10 can be eliminated, or the excision part 10 can be eliminated and only the excision part 9 can be eliminated.

  In any embodiment from the first embodiment to the fourth embodiment, the corrugated fin 6 is assumed to extend horizontally in the airflow passage direction, but the windward side is high and the leeward side is low (or vice versa) A configuration with an inclination may be used. The effect of the present invention is not limited to the case where the heat exchanger 1 is used in an upright manner, but is equally exerted when the heat exchanger 1 is used obliquely or when used horizontally.

  As mentioned above, although each embodiment of the present invention was described, the scope of the present invention is not limited to this, and various modifications can be made without departing from the spirit of the invention. For example, the application target of the present invention is not limited to a parallel flow type heat exchanger in which a flat tube is disposed between two header pipes. Parallel flow heat exchanger with more than two header pipes, for example, three header pipes, upper header pipe, middle header pipe, lower header pipe The present invention can also be applied to existing parallel flow heat exchangers. The present invention can also be applied to a parallel flow heat exchanger in which the header pipe is vertical and the flat tube is horizontal.

  The present invention is widely applicable to parallel flow heat exchangers.

The fragmentary perspective view of the heat exchanger which concerns on 1st Embodiment. Vertical sectional view of the heat exchanger according to the first embodiment Vertical sectional view of the heat exchanger according to the second embodiment The fragmentary perspective view of the heat exchanger which concerns on 3rd Embodiment. Partial horizontal sectional view of the heat exchanger according to the fourth embodiment Vertical sectional view showing the schematic structure of a conventional heat exchanger

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Heat exchanger 2, 3 Header pipe 4 Flat tube 5 Refrigerant passage 6 Corrugated fin 6a Protruding part 7 Refrigerant inlet 8 Refrigerant outlet 9 Cut part 10 Cut part

Claims (3)

A plurality of header pipes arranged in parallel at intervals, a plurality of flat tubes arranged between the plurality of header pipes and having refrigerant passages provided therein communicated with the inside of the header pipes, and the flat tubes In a heat exchanger with corrugated fins arranged between,
The corrugated fin is provided with a cut portion at the windward end of the airflow passing through it.
The cut portion is provided at a bending portion of the corrugated fin, and has a depth at which contact between the flat tube and the corrugated fin starts or a depth reaching the leeward side beyond the portion. Heat exchanger. 2. The heat exchanger according to claim 1, wherein the cut portion is provided in a plane portion intermediate between the folded portion and the folded portion of the corrugated fin. The upwind-side ends of the corrugated fins are projecting upwind than upwind side end portion of the flat tube, according to claim 1 or 2, characterized in that the cutout is provided in the projection portion Heat exchanger.

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