JP2012097920A - Heat exchanger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a heat exchanger having high heat exchange performance by improving adhesion between fins and a heat transfer tube having a plurality of flow paths.
In a heat exchanger comprising a plurality of fins 1 arranged in parallel at a predetermined interval and a heat transfer tube 2 inserted through the fin 1 and through which a heat medium flows, the heat transfer tube 2 is expanded. And a partition wall tube 9 provided inside the outer tube 20 and fixed to the outer tube 20 by being expanded. Is.
[Selection] Figure 3

Description

  The present invention relates to a finned tube heat exchanger including a plurality of fins arranged at predetermined intervals and a heat transfer tube that is inserted through the fins and through which a fluid flows.

  As a tube of a conventional finned tube heat exchanger, there is a flat multi-hole tube in which a plurality of channels through which a refrigerant flows is provided in a tube having a flat cross section. As a method of joining the tube and the fin, a method of expanding the pipe by filling the flow path with a fluid and increasing the pressure of the fluid, or mechanically inserting a plug into each of the plurality of flow paths. A method of expanding the tube is used (for example, see Patent Document 1).

JP 2009-85468 A

  In expanding the tube of the flat multi-hole tube as described above, since the partition wall portion exists between the flow paths, the entire outer peripheral surface of the tube is not expanded uniformly. For this reason, there is a problem that the fin and the tube are not sufficiently adhered to each other, and a desired heat exchange performance cannot be obtained.

  The present invention has been made to solve the above-described problems, and provides a heat exchanger having high heat exchange performance by improving the adhesion between the fins and the heat transfer tube having a plurality of flow paths. With the goal.

  The heat exchanger according to the present invention is a heat exchanger including a plurality of fins arranged in parallel at predetermined intervals and a heat transfer tube that is inserted through the fin and through which a heat medium flows, and the heat transfer tube is expanded. Thus, a cylindrical outer tube fixed to the fin and a partition tube provided inside the outer tube and fixed to the outer tube by being expanded are provided.

  According to this invention, the adhesion between the fins and the heat transfer tube having a plurality of flow paths is improved, and a heat exchanger having high heat exchange performance can be obtained.

It is a figure which shows the outline of the heat exchanger which concerns on Embodiment 1 of this invention. It is BB sectional drawing of the principal part of FIG. It is CC sectional drawing of the principal part of FIG. It is a figure which shows the insertion process of the outer tube | pipe in the manufacturing method of the heat exchanger which concerns on Embodiment 1 of this invention. It is a figure which shows the pipe expansion process of the outer tube | pipe in the manufacturing method of the heat exchanger which concerns on Embodiment 1 of this invention. It is a figure which shows the insertion process of the partition pipe in the manufacturing method of the heat exchanger which concerns on Embodiment 1 of this invention. It is a figure which shows the pipe expansion process of the partition pipe in the manufacturing method of the heat exchanger which concerns on Embodiment 1 of this invention. It is sectional drawing which shows a mode that the heat exchanger tube in which the outer tube and the partition tube were integrally formed was expanded. It is sectional drawing which shows a mode that the heat exchanger tube which concerns on Embodiment 1 of this invention was expanded. It is sectional drawing which shows the principal part of the heat exchanger which concerns on Embodiment 2 of this invention. It is a figure which shows the partition pipe of the heat exchanger which concerns on Embodiment 3 of this invention. It is sectional drawing which shows the principal part of the heat exchanger which concerns on Embodiment 4 of this invention.

Embodiment 1 FIG.
1 to 3 show a heat exchanger 100 according to Embodiment 1 for carrying out the present invention. FIG. 1 is a diagram showing an outline of the heat exchanger, and FIG. 2 is a schematic diagram of FIG. FIG. 3 is a cross-sectional view taken along the line C-C of the main part of FIG. 1.

  The heat exchanger 100 is a fin tube type heat exchanger, and as shown in FIG. 1, a plurality of fins 1 arranged in parallel with each other at a predetermined interval FP, and the fins 1 are provided. A plurality of heat transfer tubes 2 that are fixed to the insertion holes 4 at a predetermined interval DP and in which the refrigerant flows are connected to both ends of the heat transfer tubes 2 by brazing or the like, and the refrigerant flows to the heat transfer tubes 2. It is provided with the distribution pipe 3 to perform heat exchange with the air flowing from the direction A.

  The fin 1 is a thin metal plate having a thickness of 0.09 to 0.2 mm made of aluminum, an aluminum alloy, copper, a copper alloy, or the like, and has a surface treatment film (not shown) for anticorrosion, antifouling, and hydrophilic purposes. ) Is formed. Depending on the application of the heat exchanger 100, a surface treatment film for water repellency is formed. A slit 7 cut and raised from the fin base surface 1 a is provided between the insertion holes 4 of the fin 1 so as to face the air flow direction A. The slit 7 has an effect of facilitating heat transfer and increasing heat exchange performance by thinning the velocity boundary layer and the temperature boundary layer of the air flow at the side end portion. The height of the slit 7 is substantially half of the stacking interval FP of the fins 1.

  Further, as shown in FIG. 2, a fin collar 5 for bringing the fin 1 and the heat transfer tube 2 into close contact is provided around the insertion hole 4 of the fin 1. By providing the fin collar 5 in this manner, the contact area between the fin 1 and the heat transfer tube 2 can be increased, and the heat transfer performance can be improved. Further, around the tip of the fin collar 5 is provided a fin flaring 6 by bending the fin 1 so that the fins 1 are stacked at a predetermined interval FP. The interval FP is appropriately determined depending on the characteristics of the heat exchanger, and is generally about 1.0 mm to 2.0 mm.

  As shown in FIGS. 2 and 3, the heat transfer tube 2 is in close contact with the inner periphery of the insertion hole 4 of the fin 1 by inserting a tube expansion billet and expanding the tube, and is a cylindrical outer tube fixed to the fin 1. 20 and a partition wall tube 9 provided inside the outer tube 20 and fixed to the inner peripheral surface 20 b of the outer tube 20.

  The outer tube 20 is a metal cylinder made of copper, a copper alloy, aluminum, an aluminum alloy, or the like, and is formed by a processing method such as extrusion molding or pultrusion molding. A groove 10 that extends linearly in the longitudinal direction of the outer tube 20 is provided on the inner peripheral surface 20 b of the outer tube 20. The groove 10 may have a spiral shape extending at a certain angle in the longitudinal direction of the outer tube 20.

  The partition wall tube 9 is provided with a cylindrical first partition wall portion 11 located at the center of the heat transfer tube 2 and radially projecting from the outer peripheral surface 11a of the first partition wall portion 11 at equal intervals. The part 12a is composed of six second partition walls 12 that are in contact with the inner peripheral surface 20b of the outer tube 20. Here, the partition wall 9 is inserted into the cylindrical interior 11 c of the first partition wall 11 and expanded from the inner peripheral surface 11 b side, so that the end 12 a of the second partition wall 12 is connected to the outer tube 20. It is closely attached and fixed to the inner peripheral surface.

  The first partition wall 11 and the second partition wall 12 are made of copper, copper alloy, aluminum, aluminum alloy, or the like, and are integrally formed by a processing method such as extrusion molding or pultrusion molding. The thickness of the partition wall 11 and the thickness of the second partition wall 12 are 0.2 to 0.4 mm. In addition, the 1st partition part 11 and the 2nd partition part 12 may be made into a separate member, and they may be integrally formed by welding.

  The refrigerant (not shown) flowing inside the heat transfer tube 2 of the heat exchanger 100 configured as described above is composed of the inner peripheral surface 20b of the outer tube 20, the outer peripheral surface 11a of the first partition wall portion 11, and the second partition wall. A total of seven channels including the six channels 35 separated by the side surface 12b of the part 12 and the interior 11c of the first partition wall 11 are circulated.

  Next, the manufacturing method of the heat exchanger 100 which concerns on this Embodiment is demonstrated using FIGS. 4 is a diagram showing the outer tube insertion step, FIG. 5 is a diagram showing the outer tube expansion step, FIG. 6 is a diagram showing the partition tube insertion step, and FIG. 7 is a diagram showing the partition tube expansion step. It is.

  First, as shown in FIG. 4, the cylindrical outer tube 20 is inserted through the insertion holes 4 of the plurality of fins 1 stacked so as to be parallel to each other at a predetermined interval FP. Here, the outer diameter of the outer tube 20 is small with respect to the insertion hole 4 and has a dimensional relationship that allows easy insertion.

  Next, as shown in FIG. 5, the tube expansion billet 8 is pushed into the outer tube 20 inserted through the insertion hole 4. As a result, the outer tube 20 is expanded, and is sequentially brought into close contact with the fins 1 and fixed. In addition, as a material of this pipe expansion billet 8, the hardened steel is used, for example. Further, the mechanical pipe expansion method using the billet 8 may be either the pushing direction or the pulling direction with respect to the outer pipe 2. Moreover, the expansion ratio of the outer tube 20 is 5 to 7%.

  Next, as shown in FIG. 6, the partition tube 9 is inserted into the outer tube 20 fixed to the fin 1. The outer diameter of the partition tube 9 is set smaller than the inner diameter of the outer tube 20 and has a dimensional relationship that allows easy insertion.

  Then, as shown in FIG. 7, the pipe expansion billet 13 is pushed into the inside 11 c of the first partition wall portion 11 of the partition wall component 9. Then, the first partition wall 11 is expanded, and the end 12a of the second partition wall 12 protruding from the first partition wall 11 is in close contact with the inner peripheral surface 20b of the outer tube 20 and fixed. . In addition, as a material of the material of the pipe expansion billet 13, hardened steel is used, for example. Further, the mechanical pipe expansion method using the billet 13 may be either the pushing direction or the pulling direction with respect to the partition wall 9.

  Finally, the heat exchanger 100 is completed by connecting the distribution pipes 3 to both ends of the heat transfer tubes 2 fixed to the fins 1 by brazing.

In addition, the expansion billet with a circular cross section used when expanding a cylindrical tube like the expansion of the outer tube 20 and the partition tube 9 described above has been widely used conventionally, and is obtained at a relatively low cost. Is possible.
Also, as a method of expanding a heat transfer tube having a large number of flow paths that makes it difficult to expand the tube with a tube expansion billet, the heat transfer tube is filled with a fluid such as liquid or gas, and the pressure of the fluid is increased to expand the tube. Although it is difficult to control the fluid pressure uniformly over the entire heat transfer tube, the tube expansion method using the fluid pressure has low adhesion between the fin and the heat transfer tube. On the other hand, since the heat exchanger 100 according to the present embodiment can increase the number of the flow paths 35 by increasing the number of the second partition walls 12, the cross section is circular even when a large number of flow paths are formed. A mechanical pipe expanding method using the pipe expanding billet can be used.

  Next, a comparison after the expansion of the heat transfer tube 2 in the present embodiment and the heat transfer tube 50 in which the outer tube and the partition tube are integrally formed will be described below with reference to FIGS. 8 and 9. FIG. 8 is a view showing a state where the heat transfer tube 50 in which the outer tube and the partition tube are integrally formed is expanded. FIG. 9 is a view showing a state where the heat transfer tube 2 according to the present embodiment is expanded, (a) is a view showing a state where the outer tube is expanded, and (b) is a view showing a state where the partition tube is expanded. It is.

As shown in FIG. 8, the heat transfer tube 50 is formed by integrally forming an outer tube and a partition tube, and a cylindrical tube provided with flow paths 53 and 54 separated by partition portions 51 and 52. It is. Then, the expanded billet is inserted into each of the flow paths 53 and 54 to expand the tube, and is fixed to the fin 1. Here, the wall portion 52 is deformed in the radial direction of the heat transfer tube 50 by the tube expansion billet inserted into the flow path 54, but does not reach the diameter of the heat transfer tube 50 by pressing the outer peripheral surface. Even if the pressing force is increased to increase the diameter, the wall 52 is buckled and damaged. As a result, the entire outer peripheral surface of the heat transfer tube 50 is not expanded uniformly, and a dent 55 is formed, and reliable adhesion between the fins 1 and the heat transfer tube 50 cannot be obtained.
On the other hand, in the heat transfer tube 2 according to the present embodiment, first, as shown in FIG. 9A, the outer tube 20 is expanded and fixed, and then, as shown in FIG. Since 9 is expanded and fixed, the entire outer peripheral surface is expanded uniformly as described above, and reliable adhesion between the fin 1 and the heat transfer tube 2 is obtained.

  According to the present embodiment, the heat transfer tube 2 is provided in the outer tube 20 that forms a cylinder fixed to the fin 1 by being expanded, and the outer tube 20 is expanded and provided inside the outer tube 20. Since the fixed partition wall 9 is provided, the adhesion between the fins 1 and the heat transfer tubes 2 having a plurality of flow paths is improved, and a heat exchanger having high heat exchange performance can be obtained.

  The partition tube 9 is a second partition wall 11 having a cylindrical shape, and a second partition wall projecting from the outer peripheral surface 11 a of the first partition wall portion 11 and contacting the inner peripheral surface 20 b of the outer tube 20. Since it has the partition part 12, a some flow path is formed and the heat transfer area inside the heat exchanger tube 2 can be increased.

  Further, even when a large number of flow paths are formed, a mechanical tube expansion method using a tube expansion billet having a circular cross section can be used, so that the good adhesion between the fins 1 and the heat transfer tubes 2 is maintained. The number of flow paths provided in the heat transfer tube 2 can be increased. Furthermore, since the expanded billet having a circular cross section has been widely used in the past and is available at a relatively low cost, the heat exchanger can be easily manufactured at low cost.

  Moreover, since the groove | channel 10 is provided in the internal peripheral surface 20b of the outer tube | pipe 20, the heat transfer area increases and the heat exchanger which has higher heat exchange performance can be obtained.

  Further, since the outer tube 20 has a cylindrical shape, the entire outer peripheral surface is uniformly expanded, and reliable adhesion to the fin 1 is obtained.

  Further, since the first partition wall 11 has a cylindrical shape, the entire outer peripheral surface 11 a is uniformly expanded, and the end 12 a of the second partition wall 12 is securely connected to the inner peripheral surface 20 b of the outer tube 20. In close contact.

  Moreover, since the 2nd partition part 12 protrudes radially, it can fix to the outer tube 20 reliably. Further, since the second partition wall portions 12 are arranged at equal intervals, the second partition wall portions 12 can be more reliably fixed to the outer tube 20.

Embodiment 2. FIG.
FIG. 10 shows a cross-sectional view of a main part of a heat exchanger 200 according to Embodiment 2 for carrying out the present invention. In Embodiment 1, although what showed the heat exchanger tube 2 with the cylindrical outer tube 20 and the partition tube 9 which has the cylindrical 1st partition part 11 was shown, as shown in FIG. You may make it comprise with the cylindrical outer tube | pipe 22 and the partition tube 9 which has the 1st partition part 21 of a flat cylindrical shape. Since other configurations are the same as those of the first embodiment, description thereof is omitted.

  According to the present embodiment, since the flat cylindrical outer tube 22 is used, in addition to the same effect as in the first embodiment, the resistance between the fin 1 and the heat transfer tube 2 can be increased without increasing the resistance to the air flow. A heat exchanger having higher heat exchange performance can be obtained by increasing the heat transfer area.

  Moreover, since the flat cylindrical first partition wall portion 21 is used, in addition to the same effects as those of the first embodiment, the heat transfer area with the refrigerant circulating in the heat transfer tube 2 is increased to increase the heat. A heat exchanger having exchange performance can be obtained.

  In the present embodiment, the configuration in which both the outer tube 22 and the first partition wall portion 21 are formed in a flat cylindrical shape is shown, but either one may be formed in a flat cylindrical shape and the other in a cylindrical shape. Good.

Embodiment 3 FIG.
FIG. 11 shows a partition pipe of a heat exchanger 300 according to Embodiment 3 for carrying out the present invention. In the first embodiment, the configuration in which the second wall body portion of the partition tube 9 is formed radially has been shown. However, as shown in FIG. 11, the second wall body portion 24 formed in a spiral shape may be used. Good. The second partition wall 24 is formed by extrusion molding or pultrusion processing, and is formed in a spiral shape by applying a rotational motion at the die outlet. Further, the first partition wall portion 11 and the second partition wall portion 24 are separate members, and the second partition wall portion 24 formed in a spiral shape is welded to the first partition wall portion 11 so as to be integrally formed. Also good. Since other configurations are the same as those of the first embodiment, description thereof is omitted.

  According to the present embodiment, since the second partition wall portion 24 formed in a spiral shape is used, in addition to the effects of the first embodiment, a swirling flow is generated in the refrigerant flowing inside the heat transfer tube 2. Thus, heat transfer is promoted, and a heat exchanger having higher heat exchange performance can be obtained.

  In the present embodiment, the first partition wall 11 having a cylindrical shape is used, but the same effect can be obtained by using the flat cylindrical shape shown in the second embodiment.

Embodiment 4 FIG.
FIG. 12 shows a cross-sectional view of a main part of a heat exchanger 400 according to Embodiment 4 for carrying out the present invention. In the first embodiment, the configuration in which the groove 10 is provided only on the inner peripheral surface 20b of the outer tube 20 is shown. In addition to this, as shown in FIG. 12, the outer peripheral surface of the first partition wall portion 11 of the partition tube 9 The groove 10 may be provided also on the side surface 12b of the second partition wall portion 11a and the inner peripheral surface 11b. Since other configurations are the same as those of the first embodiment, description thereof is omitted.

  According to the present embodiment, the grooves 10 are also provided in the outer peripheral surface 11a and the inner peripheral surface 11b of the first partition wall portion 11 and the side surface 12b of the second partition wall portion 12. Therefore, the first embodiment will be described. In addition to the above effects, a heat exchanger having higher heat exchange performance can be obtained by increasing the heat transfer area with the refrigerant circulating in the heat transfer tube 2.

  In the present embodiment, the first partition wall 11 having a cylindrical shape is used, but the same effect can be obtained by using the flat cylindrical shape shown in the second embodiment. Moreover, although what was comprised using the 2nd partition part 12 formed radially was shown, even what is comprised with the 2nd partition part 24 formed in the spiral shape shown in Embodiment 2. The same effect is obtained.

  Moreover, although each said embodiment showed the structure which provides six 2nd partition parts, the number of the 2nd partition parts can be set arbitrarily. The number is preferably about 4 to 8.

  Moreover, although the structure by which the several heat exchanger tube was penetrated by the fin was shown, it is not limited to this, For example, a heat exchanger is comprised so that one heat exchanger tube may be folded and it may be inserted in a fin multiple times. You may make it do.

DESCRIPTION OF SYMBOLS 1 Fin 2 Heat-transfer tube 8, 13 Expanded billet 9 Partition tube 10 Groove 11, 21 First partition part 11a First partition part outer peripheral surface 11b First partition part inner peripheral surface 12, 24 Second partition part 12b Second partition Side surfaces 20, 22 Outer tube 20b Outer tube inner peripheral surface 100, 200, 300, 400 Heat exchanger

Claims (14)

In a heat exchanger comprising a plurality of fins arranged in parallel at predetermined intervals, and a heat transfer tube that is inserted through the fins and through which a heat medium flows,
The heat transfer tube is a tubular outer tube fixed to the fin by being expanded; and
A heat exchanger, comprising: a partition pipe provided inside the outer pipe and fixed to the outer pipe by being expanded.   The heat exchanger according to claim 1, wherein the outer tube is a cylinder.   The heat exchanger according to claim 1, wherein the outer tube is a flat cylinder.   The heat exchanger according to any one of claims 1 to 3, wherein the outer pipe has a groove formed on an inner peripheral surface thereof. The partition pipe is a first partition part having a cylindrical shape,
5. The second partition wall portion protruding from the outer peripheral surface of the first partition wall portion and abutting against the inner peripheral surface of the outer tube. 6. Heat exchanger.   The heat exchanger according to claim 5, wherein the first partition wall is a cylinder.   The heat exchanger according to claim 5, wherein the first partition wall is a flat cylinder.   The heat exchanger according to any one of claims 5 to 7, wherein the second partition walls are arranged at equal intervals.   The heat exchanger according to any one of claims 5 to 8, wherein the second partition wall portion is formed radially.   The heat exchanger according to any one of claims 5 to 8, wherein the second partition wall is formed in a spiral shape.   11. The heat exchanger according to claim 5, wherein the first partition wall has a groove formed in at least one of an inner peripheral surface and an outer peripheral surface thereof.   The heat exchanger according to any one of claims 5 to 11, wherein a groove is formed on a side surface of the second partition wall.   The heat exchanger according to any one of claims 1 to 12, wherein the outer tube is expanded using an expanded billet.   The heat exchanger according to any one of claims 1 to 13, wherein the partition pipe is expanded using an expanded billet.

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