JP2018151110A - Parallel flow heat exchanger and manufacturing method thereof - Google Patents

Abstract

Disclosed is a heat exchanger capable of suppressing the drift of a gas-liquid two-phase flow refrigerant to each flat tube with a small number of components and improving the heat exchange performance, and a method for manufacturing the same. An upper header pipe and a lower header pipe arranged in a horizontal direction, a plurality of parallel flat tubes connected between the upper and lower header pipes in a vertical direction, and the flat tubes In the parallel flow type heat exchanger having a corrugated fin 5 interposed therebetween, a refrigerant inflow pipe 8 is connected to the lower header pipe 3, a refrigerant outflow pipe 7 is connected to the upper header pipe 2, and a flat pipe 4 has a plurality of refrigerant flow paths 4 a, 4 b, 4 c, 4 d, 4 e, 4 f that are parallel to each other along the longitudinal direction of the flat tube 4, and a flat tube on the end side connected to the lower header pipe 3. 4 is formed so that the surfaces of 4 are opposed to each other, and an end 41 of the bent portion 40 is connected to the lower header pipe 3. [Selection] Figure 2

Description

  The present invention relates to a parallel flow type heat exchanger comprising a plurality of flat tubes connected between upper and lower header pipes arranged in a horizontal direction, and fins interposed between the flat tubes, and a method for manufacturing the same. It is about.

  In general, this type of heat exchanger includes a pair of header pipes and a plurality of flat tubes connected to both header pipes, and is widely used as a heat exchanger for car air conditioners and room air conditioners.

  As a conventional heat exchanger of this type, a pair of header pipes that are horizontal with respect to the installation surface facing up and down, a plurality of flat tubes that are connected to each other in the vertical direction, and between the flat tubes There is known a parallel flow heat exchanger having fins interposed between the two. When this heat exchanger is used as an evaporator, the refrigerant flows in from the lower header pipe and is discharged from the upper header pipe.

  In this case, the refrigerant near the evaporator inlet is a gas-liquid two-phase flow in which the gas phase and the liquid phase are mixed, and the gas-liquid is separated by gravity in the lower header pipe, and the liquid is placed below the lower header pipe. If it accumulates and the connection side of a flat tube becomes gas, gas will flow preferentially, the distribution amount of a refrigerant | coolant will be biased, and the performance of a heat exchanger will not fully be exhibited.

  As means for suppressing the drift of the refrigerant, a heat exchanger is known in which the positions of the refrigerant inflow pipe and the header pipe are defined, and a swirling flow is generated in the refrigerant to improve the diversion (see, for example, Patent Document 1). .

  In the heat exchanger described in Patent Document 1, a swirling flow is generated in the refrigerant by inclining in the longitudinal direction of the header pipe so that the central axis of the refrigerant inflow pipe is offset with respect to the central axis of the header pipe. The shunt has been improved.

  Further, as another means for suppressing the drift of the refrigerant, the header pipe is divided into fixed sections using a partition plate that divides the header pipe in the longitudinal direction. The header pipe includes an outer pipe and an inner pipe provided in the outer pipe. There is known a heat exchanger having a double-pipe structure provided with a refrigerant hole that opens in each of the spaces partitioned by a partition plate (for example, see Patent Document 2).

Japanese Patent No. 5957535 JP2015-203506A

  However, in the heat exchanger described in Patent Document 1, in order to limit the continuous distance of the swirl flow and to prevent the swirl flow from being attenuated, a spiral swirl flow guide is provided inside the header pipe of the flat tube. There is a concern that a plate is disposed, and that a concave-shaped process is required at the end portion of the flat tube connected to the header pipe.

  In addition, in the heat exchanger described in Patent Document 2, it is necessary to optimize and strictly manage the partition position by the partition plate, the hole position and the hole direction of the double pipe, the sealability between the partition plate and the inner pipe, and the like. There are concerns.

  The present invention has been made in view of the above circumstances, and a heat exchanger capable of suppressing the drift of a gas-liquid two-phase flow refrigerant to each flat tube with a small number of components and improving the heat exchange performance, and a method for manufacturing the same. It is an issue to provide.

  In order to achieve the above object, a heat exchanger according to the present invention comprises an aluminum upper and lower header pipe arranged in a horizontal direction, and a plurality of parallel parallel pipes connected between the upper and lower header pipes in a vertical direction. A parallel flow type heat exchanger comprising an aluminum flat tube and an aluminum corrugated fin interposed between the flat tubes, wherein a refrigerant inflow pipe is connected to the lower header pipe, A refrigerant outflow pipe is connected to the upper header pipe, and the flat pipe has a plurality of refrigerant flow paths parallel to each other along the longitudinal direction of the flat pipe, and the flat pipe surfaces are connected to each other at one end side in the longitudinal direction. A bent portion is formed so as to be opposed to each other, and an end portion of the bent portion is connected to the lower header pipe (Claim 1).

  With this configuration, the bent portion bent at the end portion of the flat tube is connected to the side portion of the lower header pipe, and a plurality of parallel coolant flow paths provided in the flat tube are formed in the lower header. It communicates with the upper and lower regions of the longitudinal section of the pipe. Therefore, even if the refrigerant gas and liquid are biased in the lower header pipe, both the gas and liquid can be allowed to flow into the flat tube. In this case, since the bent portion is bent into a cubic curve, both gas and liquid can be allowed to flow into the flat tube with a small number of components without using a separate component.

  Moreover, in this invention, it is preferable that the distance of the bending part side surface of the said flat tube and the outer surface of the said bending part is a dimension equal to the height of the said corrugated fin.

  By configuring in this way, the bent portion of one adjacent flat tube can be brought into contact with the other flat tube and the flat tubes can be kept at a certain distance, so that the corrugated fins can be securely connected between the flat tubes. Can be arranged.

  Moreover, in this invention, it is preferable that the distance of the bending part side surface of the said flat tube and the inner surface of the said bending part is 3 times or more of the thickness of the said flat tube (Claim 4).

  If the distance between the bent portion side surface of the flat tube and the inner surface of the bent portion is smaller than three times the thickness of the flat tube, the amount of bending of the flat tube increases and the flat tube may be broken. Therefore, the bending amount of the flat tube is set to be three times or more the thickness of the flat tube.

  In the present invention, the bent portion of the flat tube is preferably bent at an angle of 45 ° to 90 ° (hereinafter referred to as a bend angle) with respect to a vertical axis along the longitudinal direction of the flat tube. (Claim 5).

  The reason why the bending angle is set to 45 ° to 90 ° is that if the bending angle is smaller than 45 °, it is necessary to take a long distance to prevent interference with the lower header pipe. The pressure loss of the refrigerant increases. On the other hand, when the bending angle is larger than 90 °, it is difficult to allow the liquid to flow into the flat tube when the gas and liquid are separated by gravity in the lower header pipe.

  By comprising in this way, both the gas-liquid of the refrigerant | coolant isolate | separated in the lower header pipe can be efficiently flowed in in a flat tube.

  Moreover, in this invention, it is preferable that the side part along the longitudinal direction of the said flat tube located in the lower part side of the said lower header pipe is arrange | positioned on the windward side (Claim 6).

  By configuring in this way, the refrigerant flow path through which the liquid easily flows can be arranged on the windward side, so that a temperature difference from the air can be taken and the performance of the heat exchanger can be improved.

  In addition, in the present invention, it is preferable that the upper and lower header pipes, the flat tubes, and the corrugated fins are brazed with a non-corrosive flux applied to the surface of the flat tubes. .

  With this configuration, the flat tube, the upper and lower header pipes, and the corrugated fins are brazed while the non-corrosive flux is applied to the surface of the complex-shaped flat tube having the bent portion. It can be brazed without using a sheet or brazing material.

The manufacturing method of the heat exchanger according to the present invention includes an aluminum upper and lower header pipe arranged in a horizontal direction, and a plurality of aluminum flat plates connected in parallel to each other between the upper and lower header pipes in a vertical direction. A parallel flow heat exchanger manufacturing method comprising: a pipe and an aluminum corrugated fin interposed between the flat tubes, wherein the flat tubes are arranged in parallel with each other along a longitudinal direction. A step of forming with an extruded profile having a path, a step of bending one end of the flat tube in the longitudinal direction so that the surfaces of the flat tube are opposed to each other, and a surface of the flat tube Applying a non-corrosive flux to
Insert the other end of the flat tube into an insertion hole provided on the side of the upper header pipe, insert the end of the bent portion into an insertion hole provided on the side of the lower header pipe, Connecting the flat tube between the upper and lower header pipes, disposing the corrugated fins between the flat tubes, and assembling the upper and lower header pipes, flat tubes and corrugated fins; And a step of carrying the upper and lower header pipes, flat tubes and corrugated fins into a furnace and brazing them by heating (Claim 8).

  By comprising in this way, the flat tube of the complicated shape which has the bending part bent so that the surface of this flat tube may face one end part of the flat tube in the longitudinal direction, and upper and lower header pipes The heat exchanger made of corrugated fins can be easily brazed without using a brazing sheet or a brazing material.

  9. The method of manufacturing a parallel flow heat exchanger according to claim 8, wherein in the step of assembling the upper and lower header pipes, flat tubes and corrugated fins, the corrugated fins are brought into contact with the adjacent flat tubes, and the folding It is preferable to arrange it in contact with the curved portion (claim 9).

  By comprising in this way, an upper and lower header pipe, a flat tube, and a corrugated fin can be brazed reliably.

  According to this invention, since it is configured as described above, the following effects can be obtained.

  (1) According to invention of Claims 1-7, the bending part formed in the edge part of a flat pipe connects to the side part of a lower header pipe, and it is a plurality mutually parallel provided in the flat pipe Since the refrigerant flow path of the refrigerant communicates with the upper and lower regions of the vertical section of the lower header pipe, even if the gas liquid of the refrigerant is biased in the lower header pipe, both the gas and liquid can flow into the flat tube. Therefore, the drift of the gas-liquid two-phase flow refrigerant to each flat tube can be suppressed by a small number of constituent members, and the heat exchange performance can be improved.

  (2) According to the inventions described in claims 8 and 9, a parallel flow heat exchanger having the effect of (1) can be easily manufactured.

It is a schematic front view which shows the parallel flow type heat exchanger which concerns on this invention. It is sectional drawing which shows the principal part of the heat exchanger which concerns on this invention. It is sectional drawing which shows the principal part of another form of the heat exchanger which concerns on this invention. It is sectional drawing which follows the II line | wire of FIG. It is sectional drawing which shows the flow of the refrigerant | coolant by which gas-liquid separation in this invention was carried out. It is a perspective view which shows the flat tube in this invention. It is the schematic front view (a), top view (b), and side view (c) of the said flat tube. It is a disassembled perspective view which shows the upper and lower header pipe, flat tube, and corrugated fin in this invention. It is a graph which shows the relationship between the thickness of the flat tube in this invention, and the deformation amount of a bending outer surface.

  EMBODIMENT OF THE INVENTION Below, the form for implementing the parallel flow type heat exchanger (henceforth a heat exchanger) concerning this invention is demonstrated in detail based on an accompanying drawing.

  As shown in FIG. 1, the heat exchanger 1 according to the present invention is vertically opposed to an installation surface (not shown) made of aluminum (including an aluminum alloy) and arranged horizontally. An upper header pipe 2 and a lower header pipe 3, a plurality of parallel aluminum flat tubes 4 connected to the upper and lower header pipes 2 and 3, and an aluminum product interposed between the flat tubes 4 adjacent to the left and right. And corrugated fins 5.

  The upper and lower header pipes 2 and 3 are formed of an aluminum cylindrical electric sewing tube or an extruded tube, and the left and right open ends are respectively closed by an end cap 6 made of aluminum.

  A refrigerant outflow pipe 7 is connected to the space 2 a of the upper header pipe 2, and a refrigerant inflow pipe 8 is connected to the space 3 a of the lower header pipe 3.

  As shown in FIGS. 2 to 5, the flat tube 4 is formed in a flat elliptical shape with flat front and back surfaces, and a plurality of parallel tubes (here, the width direction perpendicular to the longitudinal direction of the flat tube 4 (here, The refrigerant flow paths 4a, 4b, 4c, 4d, 4e, and 4f are formed in a partitioned manner.

A bent portion 40 is formed at the end of the flat tube 4 connected to the lower header pipe 3 so that the flat surfaces of the flat tube 4 face each other.
In this case, the bent portion 40 is bent into a cubic curve. That is, the bent portion 40 is bent in an arc shape in a direction orthogonal to the surface of the flat tube 4 and is bent in a parallel direction in which the surfaces face each other.

  In this case, the bent portion 40 of the flat tube 4 is bent at an angle θ (hereinafter referred to as a bend angle θ) of 90 ° with respect to the vertical axis along the longitudinal direction of the flat tube 4. Here, the case where the bending angle θ of the bent portion 40 is 90 ° has been described. However, the bending angle θ may be in the range of 45 ° to 90 °, and as shown in FIG. The angle may be 45 °.

  The reason why the bending angle θ is set to 45 ° to 90 ° is that if the bending angle θ is smaller than 45 °, it is necessary to increase the distance in order to prevent interference with the lower header pipe. For this reason, the pressure loss of the refrigerant increases. On the other hand, when the bending angle θ is larger than 90 °, it is difficult to allow the liquid to flow into the flat tube 4 when the gas and liquid are separated by gravity in the lower header pipe 3.

  The distance H1 between the bent portion side surface of the flat tube 4 and the inner surface of the bent portion 40 (hereinafter referred to as the height H1 of the bent portion) is set to be three times or more the thickness T of the flat tube 4. (See FIG. 6). The reason is that, as shown in the examples described later, when the distance, that is, the height H1 of the bent portion is smaller than three times the thickness T of the flat tube 4, the amount of bending of the flat tube 4 increases. This is because the flat tube 4 may be broken.

  In this case, the height of the corrugated fin 5 is preferably equal to or higher than the value H2 obtained by adding the height H1 of the bent portion of the flat tube 4 and the thickness T of the flat tube 4. The reason is that if the height of the corrugated fin 5 is smaller than H2, the adjacent flat tube 4 and the corrugated fin 5 do not come into contact with each other, and the thermal performance is lowered.

  In the heat exchanger 1 configured as described above, the side portion along the longitudinal direction of the flat tube 4 located on the lower side of the lower header pipe 3 is disposed on the windward side (FIGS. 2, 2A, and FIG. 4).

  By configuring in this way, the refrigerant flow path in which the liquid easily flows, for example, the lowermost refrigerant flow path 4a can be arranged on the windward side, so that a temperature difference with air can be taken and the performance of the heat exchanger 1 can be improved. Improvement can be achieved.

  In the heat exchanger 1, the upper header pipe 2, the lower header pipe 3, the flat tube 4 and the corrugated fin 5 are brazed with the non-corrosive flux F applied to the surface of the flat tube 4. In this case, non-corrosive potassium fluoroaluminate fluxes such as KAlF4 and K3AlF6 are used as the non-corrosive flux F, for example.

  As shown in FIG. 6B, in the flat tube 4 having a width W of 14 mm and a thickness T of 1.6 mm, the outer surface of the bent portion 40 before bending is formed along the longitudinal direction of the flat tube 4. A scale (not shown) in increments of 2.5 mm was applied to measure the amount of deformation of the outer surface of the flat tube 4 after being bent, and the result shown in FIG. 8 was obtained.

As a result of the measurement, when the height H1 of the bent portion was 1 and 2 times the thickness T of the flat tube 4, the bending angle was severe, so that the outer surface of the flat tube 4 was cracked. . On the other hand, when the height H1 of the bent portion is three times or more the thickness T of the flat tube 4, no cracks are generated.
Therefore, the height H1 of the bent portion of the flat tube 4 is desirably three times or more the thickness T of the flat tube 4.

Next, a method for manufacturing the heat exchanger 1 will be described.
First, the flat tube 4 is formed by an extruded shape having a plurality of refrigerant flow paths 4a, 4b, 4c, 4d, 4e, and 4f parallel to each other along the longitudinal direction (flat tube forming step).

  One end of the flat tube 4 in the longitudinal direction is bent so that the surfaces of the flat tube 4 face each other to form a bent portion 40 (bent portion forming step). In this case, the bent portion 40 is bent into a cubic curve. That is, the bent portion 40 is bent in an arc shape in a direction orthogonal to the surface of the flat tube 4 and is bent in a parallel direction in which the surfaces face each other.

  The non-corrosive flux F is applied to the surface of the flat tube 4 having the bent portion 40 formed as described above (non-corrosive flux application step).

  The other end portion of the flat tube 4 to which the non-corrosive flux F is applied, that is, the end portion 42 opposite to the bent portion 40 is inserted into the insertion hole 2b provided on the side surface of the upper header pipe 2, and the bent portion 40 is inserted. Is inserted into an insertion hole 3b provided on the side surface of the lower header pipe 3 to connect the flat tube 4 between the upper header pipe 2 and the lower header pipe 3, and between the adjacent flat tubes 4. The corrugated fins 5 are arranged, and the upper and lower header pipes 2 and 3, the flat tubes 4 and the corrugated fins 5 are assembled (assembly process). In this assembling step, the corrugated fin 5 is disposed in contact with the adjacent flat tube 4 and in contact with the bent portion 40.

  The assembled upper and lower header pipes 2 and 3, the flat tubes 4 and the corrugated fins 5 are carried into a furnace, heated and brazed (brazing step), and the heat exchanger 1 is manufactured.

  According to the heat exchanger 1 of the said embodiment, the bending part 40 formed in the edge part of the flat tube 4 is connected to the side part of the lower header pipe 3, and several parallel mutually provided in the flat tube 4 is provided. The refrigerant flow paths 4 a, 4 b, 4 c, 4 d, 4 e, 4 f communicate with the upper and lower regions of the vertical section of the lower header pipe 3. Since both liquids can flow into the flat tube 4, the minimum number of constituent members constituting the heat exchanger 1 suppresses the drift of the gas-liquid two-phase flow refrigerant to each flat tube, and heat exchange. The performance can be improved.

  According to the manufacturing method of the heat exchanger of the said embodiment, the flat shape of the complicated shape which has the bending part 40 bend | folded so that the surface of this flat tube 4 may oppose the end part of the flat tube 4 in the longitudinal direction The heat exchanger 1 including the pipe 4, the upper and lower header pipes 2 and 3, and the corrugated fins 5 can be easily brazed without using a brazing sheet or a brazing material.

  In this case, when assembling the upper and lower header pipes 2 and 3, the flat tube 4 and the corrugated fin 5, the corrugated fin 5 is disposed in contact with the adjacent flat tube 4 and in contact with the bent portion 40. The upper and lower header pipes 2 and 3, the flat tube 4 and the corrugated fin 5 can be securely brazed.

DESCRIPTION OF SYMBOLS 1 Heat exchanger 2 Upper header pipe 2b Insertion hole 3 Lower header pipe 3b Insertion hole 4 Flat tube 4a, 4b, 4c, 4d, 4e, 4f Refrigerant flow path 5 Corrugated fin 7 Refrigerant outflow pipe 8 Refrigerant inflow pipe 40 Bending part θ Bending angle H1 Bending section height T Flat tube thickness F Non-corrosive flux

Claims (9)

Aluminum upper and lower header pipes arranged in a horizontal direction, a plurality of parallel aluminum flat pipes connected in a vertical direction between the upper and lower header pipes, and interposed between the flat pipes. An aluminum corrugated fin, and a parallel flow type heat exchanger comprising:
A refrigerant inlet pipe is connected to the lower header pipe,
A refrigerant outflow pipe is connected to the upper header pipe,
The flat tube has a plurality of parallel coolant flow paths along the longitudinal direction of the flat tube, and a bent portion that is bent so that the surfaces of the flat tube face each other at one end side in the longitudinal direction. Formed, and the end of the bent portion is connected to the lower header pipe,
A parallel flow type heat exchanger characterized by that. In the parallel flow type heat exchanger according to claim 1,
The parallel flow heat exchanger, wherein the bent portion is bent in a cubic curve. In the parallel flow type heat exchanger according to claim 1 or 2,
The parallel flow heat exchanger according to claim 1, wherein a distance between the bent portion side surface of the flat tube and the outer surface of the bent portion is equal to the height of the corrugated fin. In the parallel flow type heat exchanger according to any one of claims 1 to 3,
The parallel flow heat exchanger, wherein a distance between the bent portion side surface of the flat tube and the inner surface of the bent portion is at least three times the thickness of the flat tube. In the parallel flow type heat exchanger according to any one of claims 1 to 4,
The parallel flow heat exchanger according to claim 1, wherein the bent portion of the flat tube is bent at an angle of 45 ° to 90 ° with respect to a vertical axis along the longitudinal direction of the flat tube. In the parallel flow type heat exchanger according to any one of claims 1 to 5,
The parallel flow type heat exchanger, wherein a side portion along the longitudinal direction of the flat tube located on the lower side of the lower header pipe is disposed on the windward side. In the parallel flow type heat exchanger according to any one of claims 1 to 5,
A parallel flow type heat exchanger, wherein the upper and lower header pipes, the flat tubes, and the corrugated fins are brazed with a non-corrosive flux applied to the surface of the flat tubes. Aluminum upper and lower header pipes arranged in a horizontal direction, a plurality of parallel aluminum flat pipes connected in a vertical direction between the upper and lower header pipes, and interposed between the flat pipes. An aluminum corrugated fin, and a parallel flow type heat exchanger manufacturing method comprising:
Forming the flat tube with an extruded profile having a plurality of refrigerant flow paths parallel to each other along the longitudinal direction;
Bending the one end portion of the flat tube in the longitudinal direction so that the surfaces of the flat tube face each other, and forming a bent portion;
Applying a non-corrosive flux to the surface of the flat tube;
Insert the other end of the flat tube into an insertion hole provided on the side of the upper header pipe, insert the end of the bent portion into an insertion hole provided on the side of the lower header pipe, Connecting the flat tube between the upper and lower header pipes, placing the corrugated fins between the flat tubes, and assembling the upper and lower header pipes, flat tubes and corrugated fins;
Carrying the assembled upper and lower header pipes, flat tubes and corrugated fins into a furnace and brazing by heating;
A method for producing a parallel flow heat exchanger. In the manufacturing method of the parallel flow type heat exchanger according to claim 8,
In the step of assembling the upper and lower header pipes, flat tubes and corrugated fins, the corrugated fins are disposed in contact with the adjacent flat tubes and in contact with the bent portions. A manufacturing method of a mold heat exchanger.

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