JP2020076532A - Heat exchanger - Google Patents

Abstract

To enhance the heat exchanging capacity of a heat exchanger including an aluminum or aluminum alloy circular tube.SOLUTION: A heat exchanger (10) includes a fin (20) formed with a circular through-hole (21), and a circular tube (30) formed of aluminum or aluminum alloy, the circular tube (30) being inserted through the through-hole (21) of the fin (20) and fixed to the fin (20) with tube expansion to expand the circular tube (30) and joint using a joint material. Herein, 3 mm≤D≤5 mm and 0.06≤t/D≤0.25 are established where D is the outer diameter of the circular tube (30) and t is the minimum thickness of the circular tube (30).SELECTED DRAWING: Figure 3

Description

  The present disclosure relates to heat exchangers.

  BACKGROUND ART Conventionally, there is known a method of manufacturing a heat exchanger in which a U-shaped pipe is inserted into a through hole of a fin and the fin and the U-shaped pipe are fixed by expanding the U-shaped pipe (for example, by expanding the U-shaped pipe). , Patent Document 1). In addition, paragraph 0018 of the document describes that the U-shaped pipe is made of copper.

JP, 2003-39164, A

  By the way, it is conceivable that the member corresponding to the U-shaped pipe, that is, the tubular body through which the refrigerant flows is made of aluminum or aluminum alloy instead of copper. However, the aluminum or aluminum alloy tube body needs to be thicker than the copper tube body, whereby the heat transfer area between the refrigerant and the external fluid is reduced, or when the refrigerant flows. It is difficult to increase the heat exchange capacity of the heat exchanger due to an increase in pressure loss of the heat exchanger.

  An object of the present disclosure is to enhance the heat exchange capacity of a heat exchanger including a circular tube made of aluminum or aluminum alloy.

  A first aspect of the present disclosure is directed to a heat exchanger (10). The heat exchanger (10) includes a fin (20) having a circular through hole (21) formed therein and a circular pipe (30) made of aluminum or an aluminum alloy. The circular pipe (30) is inserted into the through hole (21) and expanded to expand the circular pipe (30) and fixed to the fin (20) by joining using a joining material. The outer diameter of 30) is D, and the minimum wall thickness of the circular pipe (30) is t, and 3 mm ≦ D ≦ 5 mm and 0.06 ≦ t / D ≦ 0.25 are established.

  In the first aspect, 3 mm ≦ D ≦ 5 mm and 0.06 ≦ t / D ≦ 0.25 are established in the circular tube (30). That is, since D is relatively small, the pressure loss of air passing through the heat exchanger (10) (that is, the ventilation resistance of the heat exchanger (10)) can be reduced. Further, since t / D is 0.06 or more, the circular pipe (30) can be thickened to a certain extent to ensure the pressure resistance of the circular pipe (30). Further, since t / D is 0.25 or less, the pressure loss of the refrigerant flowing in the circular pipe (30) can be suppressed without excessively thickening the circular pipe (30). Further, since the circular pipe (30) is fixed to the fin (20) by the pipe expansion and the joining using the joining material, the heat transfer resistance between the circular pipe (30) and the fin (20) is reduced. be able to. As described above, according to the first aspect, the heat exchange capacity of the heat exchanger (10) including the circular pipe (30) made of aluminum or aluminum alloy can be enhanced.

  A second aspect of the present disclosure is characterized in that, in the first aspect, the bonding material is a brazing material or an adhesive.

  In the second aspect, by using the brazing material or the adhesive, the heat transfer resistance between the circular pipe (30) and the fin (20) can be surely reduced.

  A third aspect of the present disclosure is characterized in that, in the first or second aspect, the circular tube (30) extends linearly as a whole.

  In the third aspect, the circular pipe (30) can be made suitable for expansion by fluid pressure. That is, since the entire circular pipe (30) extends linearly, there is no portion (typically a curved portion) that becomes weaker than other portions when expanded by fluid pressure, and the circular pipe (30 The circular pipe (30) can be expanded sufficiently while avoiding damage to the pipe (30).

  A fourth aspect of the present disclosure is the method according to any one of the first to third aspects, wherein the plurality of circular pipes (30) are provided and the inside of two or more circular pipes (30) is provided. A communication space (41, 51, 61) communicating with the space is provided with a header (40, 50, 60) formed therein.

  In the fourth aspect, the header (40, 50, 60) splits or merges the refrigerant with respect to the two or more circular pipes (30), and instead or in addition to the heat exchanger (10). When the pipes (30) are arranged in a plurality of rows in the air flow direction, a connecting portion between the circular pipes (30) forming a certain row and the circular pipes (30) forming an adjacent row can be formed.

  According to a fifth aspect of the present disclosure, in any one of the first to fourth aspects, the circular pipe (30) has a groove (32) extending along a direction in which the circular pipe (30) extends. It is characterized in that it is formed on the inner surface (31).

  In the fifth aspect, the circular tube (30) made of aluminum or aluminum alloy and having the groove (32) on the inner surface (31) can be easily manufactured by, for example, extrusion molding. When the inner surface (31) of the circular pipe (30) has a groove (32), the "minimum wall thickness of the circular pipe (30)" in the present specification means the bottom face of the groove (32) and the circular pipe (30). ) Refers to the distance between the outside surface.

  A sixth aspect of the present disclosure is characterized in that, in any one of the first to fourth aspects, the inner surface (31) of the circular pipe (30) is configured to be a smooth surface.

  In the sixth aspect, the pressure loss of the refrigerant flowing through the circular pipe (30) can be further reduced. In addition, when the inner surface (31) of the circular tube (30) is configured as a smooth surface, the "minimum wall thickness of the circular tube (30)" in the present specification means the inner surface (31) of the circular tube (30). The distance between the outer surface and the outer surface.

  A seventh aspect of the present disclosure relates to a method for manufacturing the heat exchanger (10) according to any one of the first to sixth aspects. This heat exchanger (10) is manufactured by a step of inserting the circular tube (30) into the through hole (21) of the fin (20) and expanding the circular tube (30) by fluid pressure. And a step of bringing the fin (20) into contact with the fin (20) and a step of joining the fin (20) and the circular tube (30) to each other.

  In the seventh aspect, it is possible to obtain the heat exchanger (10) having the same effects as those of the first to sixth aspects. Further, the circular pipe (30) having a relatively small diameter can be expanded by fluid pressure (that is, air pressure or hydraulic pressure) without causing unnecessary deformation.

FIG. 1 is a perspective view schematically showing the configuration of the heat exchanger of the embodiment. FIG. 2 is a sectional view taken along line II-II of FIG. FIG. 3 is a cross-sectional view showing an enlarged circular tube of the embodiment. FIG. 4 is an enlarged cross-sectional view showing a connecting portion between the circular pipe and the liquid header. FIG. 5 is an enlarged sectional view showing a connecting portion between the circular pipe and the gas header. FIG. 6 is an enlarged cross-sectional view of a connecting portion between the circular pipe and the connection header, which is shown in a plan view. FIG. 7: is a figure which shows the insertion process, the pipe expansion process, and the joining process in the manufacturing method of the heat exchanger of embodiment. FIG. 8: is a figure which shows the header fixing process in the manufacturing method of the heat exchanger of embodiment. FIG. 9 is an enlarged cross-sectional view showing a circular pipe of another embodiment.

  An embodiment will be described. The heat exchanger (10) of the present embodiment is provided in a refrigerant circuit (not shown) that performs a vapor compression refrigeration cycle and exchanges heat between the refrigerant flowing inside and the air. Below, the structure of a heat exchanger (10) is demonstrated first, and the manufacturing method of the said heat exchanger (10) is demonstrated after that.

-Structure of heat exchanger-
FIG. 1 is a perspective view schematically showing the configuration of the heat exchanger (10). FIG. 2 is a sectional view taken along line II-II of FIG. FIG. 3 is a cross-sectional view showing the circular tube (30) in an enlarged manner. FIG. 4 is an enlarged cross-sectional view showing a connecting portion between the circular pipe (30) and the liquid header (40). FIG. 5 is an enlarged sectional view showing a connecting portion between the circular pipe (30) and the gas header (50). FIG. 6 is an enlarged cross-sectional view of the connecting portion between the circular pipe (30) and the connection header (60) in plan view.

  As shown in these figures, the heat exchanger (10) is configured as a double row heat exchanger, and includes a plurality of fins (20), a plurality of circular tubes (30), a liquid header (40), A gas header (50), a connection header (60), and a flow diverter (70).

  As shown in FIGS. 1 and 2, the fins (20) are vertically elongated rectangular plate-shaped members made of aluminum or aluminum alloy, and are arranged in parallel in the left-right direction in FIG. A plurality of circular through holes (21) are formed in the fin (20). Here, the through hole (21) of the fin (20) forming the front row in FIG. 1 and the through hole (21) of the fin (20) forming the back row in FIG. The positions are different from each other (see also FIG. 2).

  As shown in FIGS. 1 to 3, the circular tube (30) is an elongated cylindrical member made of aluminum or aluminum alloy. The entire circular tube (30) extends linearly. That is, the circular pipe (30) extends linearly from one end to the other end in the longitudinal direction (the left-right direction in FIG. 1).

  The circular tube (30) is inserted and fixed in the through hole (21) of the fin (20) as shown in FIGS. 1 and 2. Here, as described below, the circular pipe (30) is expanded into the fin (20) by expanding the circular pipe (30) and joining with a joining material (for example, a brazing material) not shown. It is fixed. An adhesive may be used as the bonding material, or any other type of bonding material may be used.

  As shown in FIG. 3, the circular pipe (30) has a plurality of grooves (32) extending along the extending direction of the circular pipe (30) on the inner surface (31). These grooves (32) linearly extend from one end to the other end of the circular pipe (30) in the longitudinal direction. The plurality of grooves (32) are arranged at equal intervals in the circumferential direction of the circular pipe (30).

  Here, as shown in FIG. 3, the outer diameter of the circular pipe (30) is D, and the minimum wall thickness of the circular pipe (30), that is, the bottom surface of the groove (32) and the outer surface of the circular pipe (30). The distance between them is t. In this case, 3 mm ≦ D ≦ 5 mm and 0.06 ≦ t / D ≦ 0.25 are established. That is, the circular pipe (30) of the present embodiment has a relatively small diameter and is configured to be thick to some extent, but is not configured to be excessively thick.

  As shown in FIGS. 1 and 4, the liquid header (40) is a vertically extending cylindrical member provided corresponding to the circular tubes (30) forming the front row, and its upper end and The lower end is closed. Inside the liquid header (40), at least one, in this example, two liquid communication spaces (41) are formed. The upper liquid communication space (41) communicates with the internal space of two or more, in this example, five circular pipes (30). The lower liquid communication space (41) communicates with the internal space of two or more, in this example, four circular pipes (30). The liquid header (40) constitutes a header, and the liquid communication space (41) constitutes a communication space.

  As shown in FIGS. 1 and 5, the gas header (50) is a vertically extending cylindrical member that is provided corresponding to the circular tubes (30) that form the row on the far side, and its upper and lower ends. Is blocked. At least one gas communication space (51) in this example is formed inside the gas header (50). The gas communication space (51) communicates with the internal space of two or more, in this example, nine circular tubes (30). A gas pipe (82) communicating with the gas communication space (51) is connected to the gas header (50). The gas header (50) constitutes a header, and the gas communication space (51) constitutes a communication space.

  As shown in FIGS. 1 and 6, the connection header (60) is for connecting the circular tubes (30) forming the front row and the circular tubes (30) forming the rear row to each other. It is a member. The connection header (60) is formed in a hollow rectangular parallelepiped shape extending vertically. At least one, in this example, one inter-column communication space (61) is formed inside the connection header (60). This inter-row communication space (61) communicates with the internal space of two or more, in this example, all circular pipes (30). The connection header (60) constitutes a header, and the inter-row communication space (61) constitutes a communication space. In addition, in FIG. 6, two circular tubes (30) having different height positions are actually shown on the same plane.

  The flow divider (70) is a component for dividing the liquid refrigerant flowing from the liquid pipe (81). The flow distributor (70) includes a first branch pipe (71) communicating with the liquid communication space (41) above the liquid header (40) and a liquid communication space (41) below the liquid header (40). And a second branch pipe (72) communicating with. The first branch pipe (71) is open at the bottom of the upper liquid communication space (41). The second branch pipe (72) opens at the lower part of the lower liquid communication space (41).

-Method of manufacturing heat exchanger-
A method for manufacturing the heat exchanger (10) will be described. This manufacturing method includes an inserting step, a tube expanding step, a joining step, and a header fixing step. Here, FIG. 7 shows the inserting step, the tube expanding step and the joining step, and FIG. 8 shows the header fixing step.

  As shown in FIG. 7, in the inserting step, the circular pipe (30) is inserted into the through hole (21) of the fin (20). Here, the inner diameter of the through hole (21) of the fin (20) is slightly larger than the outer diameter D of the circular tube (30), so that the circular tube (30) can be inserted relatively easily.

  In the pipe expanding step, by feeding a fluid into the circular pipe (30), the circular pipe (30) is expanded by fluid pressure (that is, air pressure or hydraulic pressure), and the outer surface of the circular pipe (30) and the fins (20) are expanded. The inner edge of the through hole (21) is contacted.

  In the joining step, the fin (20) and the circular pipe (30) are joined to each other by, for example, brazing. The heat exchanger main body (11) is formed by the above steps.

  As shown in FIG. 8, in the header fixing step, the liquid header (40) is attached to one end (the right end in FIG. 8) of the circular tubes (30) that form the front row to form the back row. The gas header (50) is attached to one end portion (the right end portion in FIG. 8) of the circular pipes (30), and the connection headers (60) are attached to the other end portions of all the circular pipes (30). Then, the circular pipes (30), the liquid header (40), the gas header (50), and the connection header (60) are joined to each other by, for example, brazing.

-Effect of embodiment-
The heat exchanger (10) of the present embodiment includes a fin (20) having a circular through hole (21) formed therein and a circular pipe (30) made of aluminum or an aluminum alloy. ), The circular pipe (30) inserted into the through hole (21) and expanding the circular pipe (30) and fixed to the fin (20) by joining with a joining material, Letting the outer diameter of the circular pipe (30) be D and the minimum wall thickness of the circular pipe (30) be t, 3 mm ≦ D ≦ 5 mm and 0.06 ≦ t / D ≦ 0.25 are established. Thus, in the circular tube (30), 3 mm ≦ D ≦ 5 mm and 0.06 ≦ t / D ≦ 0.25 are established. That is, since D is relatively small, the pressure loss of air passing through the heat exchanger (10) (that is, the ventilation resistance of the heat exchanger (10)) can be reduced. Further, since t / D is 0.06 or more, the circular pipe (30) can be thickened to a certain extent to ensure the pressure resistance of the circular pipe (30). Further, since t / D is 0.25 or less, the pressure loss of the refrigerant flowing in the circular pipe (30) can be suppressed without excessively thickening the circular pipe (30). Further, since the circular pipe (30) is fixed to the fin (20) by the pipe expansion and the joining using the joining material, the heat transfer resistance between the circular pipe (30) and the fin (20) is reduced. be able to. As described above, according to the first aspect, the heat exchange capacity of the heat exchanger (10) including the circular pipe (30) made of aluminum or aluminum alloy can be enhanced.

  Further, in the heat exchanger (10) of the present embodiment, the joining material is a brazing material or an adhesive. Therefore, by using the brazing material or the adhesive, the heat transfer resistance between the circular pipe (30) and the fin (20) can be surely reduced.

  Further, in the heat exchanger (10) of the present embodiment, the circular pipe (30) extends in a straight line as a whole. Therefore, the circular pipe (30) can be made suitable for pipe expansion by fluid pressure. That is, since the entire circular pipe (30) extends linearly, there is no portion (typically a curved portion) that becomes weaker than other portions when expanded by fluid pressure, and the circular pipe (30 The circular pipe (30) can be expanded sufficiently while avoiding damage to the pipe (30).

  Further, the heat exchanger (10) of the present embodiment is provided with a plurality of the circular pipes (30), and the liquid communication space (41) communicating with the internal space of two or more circular pipes (30). ) Is formed inside, and a gas header (50) inside which is formed a gas communication space (51) that communicates with the internal space of the two or more circular pipes (30). A connection header (60) having an inter-row communication space (61) formed therein, which communicates with the internal space of one or more circular pipes (30). Therefore, each header (40, 50, 60) divides or merges the refrigerant with respect to two or more circular pipes (30), and instead of or in addition to it, the heat exchanger (10) is arranged in the air flow direction. On the other hand, in the case of forming a plurality of rows, it is possible to form a connecting portion between the circular tubes (30) forming a certain row and the circular tubes (30) forming an adjacent row.

  Further, in the heat exchanger (10) of the present embodiment, the circular pipe (30) has a groove (32) extending along the extending direction of the circular pipe (30) on the inner surface (31). Therefore, the circular tube (30) made of aluminum or aluminum alloy and having the groove (32) on the inner surface (31) can be easily manufactured by, for example, extrusion molding.

  Further, in the heat exchanger (10) of the present embodiment, the inner surface (31) of the circular pipe (30) has a smooth surface. Therefore, the pressure loss of the refrigerant flowing in the circular pipe (30) can be further reduced.

  Furthermore, the method of manufacturing the heat exchanger (10) of the present embodiment includes an inserting step of inserting the circular tube (30) into the through hole (21) of the fin (20), and a whole extending linearly. It includes a tube expanding step of expanding the circular tube (30) by fluid pressure so as to contact the fin (20), and a joining step of joining the fin (20) and the circular tube (30) to each other. Therefore, a straight circular tube (30) having no weak portion (typically, a curved portion) can be expanded by fluid pressure (that is, pneumatic pressure or hydraulic pressure) without unnecessary deformation. it can.

<< Other Embodiments >>
The above embodiment may have the following configurations.

  For example, as shown in FIG. 9, the inner surface (31) of the circular tube (30) may be a smooth surface. Here, the outer diameter of the circular pipe (30) is D, and the minimum wall thickness of the circular pipe (30), that is, the distance between the inner surface (31) and the outer surface of the circular pipe (30) is t. In this case, 3 mm ≦ D ≦ 5 mm and 0.06 ≦ t / D ≦ 0.25 are established.

  In the above embodiment, the fin (20) and the circular pipe (30) are joined to each other, and the header fixing (40, 50, 60) is performed by attaching the headers (40, 50, 60) to the heat exchanger body (11). Although the step and the step are performed separately, the fins (20), the circular tubes (30), and the headers (40, 50, 60) may be joined at the same time.

  Further, in the completed heat exchanger (10), the circular pipe (30) does not have to extend in a straight line as a whole, and may be bent into, for example, a substantially L shape in a top view. Here, in the manufacturing method of the heat exchanger (10) including the bent circular pipe (30), the step of bending the circular pipe (30) (more broadly, the heat exchanger (10)) is a header fixing step. Is finished (that is, after the fin (20) and each header (40, 50, 60) are fixed to the circular pipe (30) by brazing). In the pipe expanding step in the manufacturing method, a work of expanding the straight circular pipe (30) before bending is performed.

  Although the embodiments and modifications have been described above, it will be understood that various changes in form and details can be made without departing from the spirit and scope of the claims. In addition, the above-described embodiments and modified examples may be appropriately combined or replaced as long as the functions of the object of the present disclosure are not impaired.

  As explained above, the present disclosure is useful for heat exchangers.

10 heat exchanger
20 fins
21 through holes
30 round tube
31 Inside
32 grooves
40 liquid header (header)
41 fluid communication space (communication space)
50 gas header (header)
51 Gas communication space (communication space)
60 Connection Header (Header)
61 communication space between rows (communication space)
t Minimum wall thickness of circular pipe
Outer diameter of D circular pipe

Claims (7)

A fin (20) having a circular through hole (21),
A circular pipe (30) made of aluminum or an aluminum alloy, which is inserted into the through hole (21) of the fin (20) and expands the circular pipe (30) by using a joining material. A circular pipe (30) fixed to the fin (20) by
Letting the outer diameter of the circular pipe (30) be D and the minimum wall thickness of the circular pipe (30) be t, 3 mm ≦ D ≦ 5 mm and 0.06 ≦ t / D ≦ 0.25 should be satisfied. Characteristic heat exchanger. In claim 1,
The heat exchanger, wherein the joining material is a brazing material or an adhesive. In claim 1 or 2,
The heat exchanger characterized in that the circular tube (30) extends in a straight line as a whole. In any one of Claims 1-3,
A plurality of the circular tubes (30) are provided,
A heat exchanger comprising a header (40, 50, 60) in which a communication space (41, 51, 61) communicating with the internal space of two or more circular pipes (30) is formed. In any one of Claims 1-4,
The heat exchanger characterized in that the circular pipe (30) has a groove (32) extending along the extending direction of the circular pipe (30) formed on the inner surface (31). In any one of Claims 1-4,
The heat exchanger characterized in that the inner surface (31) of the circular pipe (30) is formed into a smooth surface. A method for manufacturing the heat exchanger (10) according to any one of claims 1 to 6, comprising:
An inserting step of inserting the circular tube (30) into the through hole (21) of the fin (20),
A pipe expanding step in which the circular pipe (30) is expanded by fluid pressure and brought into contact with the fins (20);
A method of manufacturing a heat exchanger, comprising a joining step of joining the fin (20) and the circular tube (30) to each other.

Images