WO2019058514A1 - Heat exchanger, refrigeration cycle device, and method for manufacturing heat exchanger - Google Patents

Abstract

The heat exchanger has a flat cross section, and is connected to a plurality of heat transfer tubes in which a plurality of inner holes are formed, a plurality of fins to which a plurality of heat transfer tubes are joined, and a plurality of heat transfer tubes. And a header having a fluid flow passage inside, the cross-sectional long axis of the heat transfer tube is da, the number of inner holes of the heat transfer tube is n, the thickness of the outer wall of the heat transfer tube is tp, the heat transfer tube needs Assuming that the pressure resistance is P, the inner diameter of the header is dh, the thickness of the outer wall of the header is th, and the tensile strength of the header is σ, the header is dh / th, 2σ / {P * (da / n / tp-1)} or more.

Description

Heat exchanger, refrigeration cycle apparatus, and method for manufacturing heat exchanger

The present invention relates to a heat exchanger provided with a header, a refrigeration cycle apparatus provided with the heat exchanger, and a method of manufacturing the heat exchanger provided with the header.

As a heat exchanger used in a refrigeration cycle apparatus, a plate fin tube type heat composed of a plurality of plate-like fins arranged via a fin pitch and a plurality of circular or flat heat transfer tubes Exchangers are known. There is also known a corrugated fin-tube heat exchanger composed of a corrugated fin and a flat heat transfer tube.
The flat heat transfer tube is a heat transfer tube in which the width (in the direction of the major axis in the cross section) is larger than the longitudinal width (in the direction of the minor axis in the cross section). It is. The heat transfer tube having a flat cross-sectional shape is referred to as a flat tube. Further, the heat transfer tube having a circular cross section is referred to as a circular tube.

The corrugated fin and tube type heat exchanger generally has a configuration in which wavy fins and flat heat transfer tubes are alternately stacked.
On the other hand, the plate-fin tube type heat exchanger is configured such that the heat transfer tube is inserted into a through hole or a notch formed in the fin. The heat transfer tubes are attached to the through holes or notches of the fins so as to extend along the direction of arrangement of the fins. The notch is formed to open one side of the fin. The heat transfer tube inserted into the notch is attached to the fin by being inserted into the notch from the open side.

In these heat exchangers, in order to conduct heat exchange efficiently, a heat transfer tube with a reduced diameter may be used. A flat tube may be used as such a heat transfer tube. Inside the flat tube, a number of finely divided flow paths are formed in parallel. The flow passage formed inside the flat tube is referred to as an internal flow passage.
In addition, a heat exchanger provided with a heat transfer tube having a plurality of flow paths formed therein and a heat exchanger provided with a heat transfer tube having a groove formed on the inner surface are also known. In such a heat exchanger, the heat exchange performance is improved by increasing the surface area to be exchanged with heat by forming a plurality of flow paths inside the heat transfer pipe or forming a groove on the inner surface of the heat transfer pipe. ing.

Further, among heat exchangers, one having a header (divider) is known. In such a heat exchanger, the end of each heat transfer tube is connected to a header that forms a refrigerant flow path together with the heat transfer tube.
In the heat exchanger, heat exchange is performed between a heat exchange fluid such as air flowing between the fins and a heat exchange fluid such as water flowing in the heat transfer pipe or a refrigerant.

The corrugated fin and tube type heat exchanger can be manufactured by alternately laminating heat transfer tubes and corrugated fins and fixing them by crimping or brazing.

A plate-fin tube type heat exchanger can be manufactured by inserting a hairpin-processed tube into a plurality of fins and pressing and expanding the inside of the tube to join the tube and the fins. This manufacturing method is referred to as an expansion method.
Moreover, a plate fin tube type heat exchanger can be manufactured by fixing by brazing a tube and a fin.

As a tube expansion method, there is known a method in which a rigid rod is inserted into a heat transfer tube to mechanically spread the heat transfer tube from the inside. This pipe expansion method is referred to as a mechanical pipe expansion method.
Moreover, as a pipe expansion method, there is known a method in which a fluid is poured into a heat transfer pipe, and pressure is spread from inside the heat transfer pipe by raising the pressure in the heat transfer pipe. This pipe expansion method is referred to as a fluid pressure expansion method.

In the case of using a circular tube in a plate finned tube type heat exchanger, the mechanical expansion method is the mainstream.
On the other hand, in the case of using a flat tube in a plate-fin tube type heat exchanger, a method is generally used in which the flat tube is inserted into fins arranged at a predetermined fin pitch and then joined by brazing. This is due to the fact that it is very difficult to insert and expand a rigid rod for a large number of parallel flow paths divided by a flat tube.

The method of joining by brazing requires a large facility such as a furnace used for brazing, and additionally, the energy for operating the large facility becomes enormous and the manufacturing cost becomes large.
On the other hand, in the fluid pressure expansion method, since the adhesion between the heat transfer pipe and the fins can be secured, the manufacturing cost can be reduced.
Therefore, Patent Document 1 discloses a technique for manufacturing a heat exchanger using a fluid pressure expansion method.

Patent No. 4109444

When a flat tube is attached to a fin by adopting a fluid pressure expansion method, in order to make the inside of the flat tube a high pressure, a large pressure also acts on pressure paths other than the flat tube. Therefore, in order to prevent fluid leakage and breakage due to local stress concentration, it is essential to seal the pressurized path. In addition, the header etc. which are connected to a flat pipe | tube etc. are mentioned as pressurization path | routes other than a flat pipe | tube.

In patent document 1, in order to secure a pressurization path | route at low cost, it is made to expand in the state which connected the flat pipe and the header previously. That is, the pressurizing path is sealed by joining the header and the flat tube by brazing or the like.

However, in Patent Document 1, it is necessary to design the inner space of the header and the header wall thickness so that the pressure resistance of the header is equal to or higher than the internal flow passage of the flat tube, and the cost required to ensure reliability It will increase.
In addition, when there is a structural restriction due to the casing size of the refrigeration cycle apparatus and the like, if the size of the header becomes large, there is a possibility that the heat exchanger can not be realized to obtain the intended performance.

Furthermore, in the plate-fin tube type heat exchanger, it is necessary to seal not only the one end on the header side of the flat tube but also the other end of the flat tube in the same manner. When the other end is also joined and sealed by brazing, the contribution of the header size to the heat exchanger performance is further increased.
On the other hand, when the other end is sealed without brazing, since the internal flow passage of the flat tube is minute, sealing from the inside of the flat tube is difficult, and a sealing means is prepared from the outside of the flat tube. There is a need.

As described above, when the fluid pressure expansion method is adopted in a state where the header and the flat tube are connected, the cost increase of the header and the weight increase of the header and the reliability of the heat exchanger are caused due to the pressure resistance design of the header. It is likely to cause a decline. That is, it is necessary to increase the wall thickness of the header to correspond to the high pressure acting on the inside of the header to ensure reliability, and the cost of the header and the weight of the header will be increased accordingly.
For this reason, a heat exchanger, a refrigeration cycle apparatus, and a method of manufacturing the heat exchanger, which can ensure the reliability of the heat exchanger while suppressing the increase in the cost of the header, are desired.

The present invention has been made to solve the above problems, and is provided with a heat exchanger that can improve the reliability of the heat exchanger while suppressing the increase in the cost of the header, and the heat exchanger. A refrigeration cycle apparatus and a method of manufacturing a heat exchanger are provided.

The heat exchanger according to the present invention has a flat cross section, and has a plurality of heat transfer pipes in which a plurality of inner holes are formed, a plurality of fins to which the plurality of heat transfer pipes are joined, and the plurality of heat transfer pipes. A header connected to the heat transfer tube and having a fluid flow passage inside, the cross section long axis of the heat transfer tube being da, the number of the inner holes of the heat transfer tube being n, the outer wall of the heat transfer tube Assuming that the thickness is tp, the necessary pressure resistance of the heat transfer tube is P, the inner diameter of the header is dh, the thickness of the outer wall of the header is th, and the tensile strength of the header is σ, the header is dh / Th is configured to be 2σ / {P * (da / n / tp-1)} or more.

A refrigeration cycle apparatus according to the present invention includes a compressor, a first heat exchanger, a throttling device, and a refrigerant circuit in which a second heat exchanger is connected by a refrigerant pipe, and the above-described heat exchanger is the first heat exchanger. The heat exchanger is used as at least one of the heat exchanger and the second heat exchanger.

In the method of manufacturing a heat exchanger according to the present invention, a plurality of through holes are formed in a plate member serving as a fin, a heat transfer pipe is inserted into each of the plurality of through holes, and one end of the heat transfer pipe Sealing, supplying the gas from the other end of the heat transfer tube to expand the heat transfer tube, the heat transfer tube is joined to the fin, and after the heat transfer tube is joined to the fin, The heat transfer tube is brazed to a header having a fluid flow passage.

According to the heat exchanger of the present invention, the thickness of the outer wall portion of the header can be made smaller compared to the inner diameter of the header, and the material cost can be reduced accordingly.
According to the refrigeration cycle apparatus of the present invention, since the above-described heat exchanger is used as at least one of the first heat exchanger and the second heat exchanger, the manufacturing cost can be reduced accordingly.
According to the method of manufacturing a heat exchanger according to the present invention, it is possible to expand a plurality of heat transfer tubes without using a header, and it is not necessary to provide the header with a pressure resistance equal to or higher than that of the heat transfer tube.

It is a schematic perspective view which shows an example of a structure of the heat exchanger which concerns on Embodiment 1 of this invention. It is a schematic side view which shows an example of the state which looked at the heat exchanger which concerns on Embodiment 1 of this invention from the flow direction of air. It is a schematic side view which shows an example of the state which looked at the heat exchanger which concerns on Embodiment 1 of this invention from the flow direction of a refrigerant | coolant. It is a schematic perspective view which shows an example of a structure of the heat exchanger which concerns on Embodiment 1 of this invention. It is a schematic side view which shows an example of the state which looked at the heat exchanger which concerns on Embodiment 1 of this invention from the flow direction of a refrigerant | coolant. It is a schematic sectional drawing which shows the cross section of the heat exchanger tube which comprises the heat exchanger which concerns on Embodiment 1 of this invention. It is a schematic front view of the fin which comprises the heat exchanger which concerns on Embodiment 1 of this invention. It is a schematic side view of the fin which comprises the heat exchanger which concerns on Embodiment 1 of this invention. It is a schematic top view of the fin which comprises the heat exchanger which concerns on Embodiment 1 of this invention. It is a schematic perspective view which shows the structural example of the header with which the heat exchanger which concerns on Embodiment 1 of this invention is provided. It is a schematic sectional drawing which shows an example of a cross-sectional structure of the header with which the heat exchanger which concerns on Embodiment 1 of this invention is provided. It is a schematic sectional drawing which shows another example of the cross-sectional structure of the header with which the heat exchanger which concerns on Embodiment 1 of this invention is provided. It is a flowchart which shows roughly the process of the manufacturing method of the heat exchanger which concerns on Embodiment 1 of this invention. It is explanatory drawing for demonstrating an example of how to attach to the instrument for sealing of the heat exchanger tube in the manufacturing method of the heat exchanger which concerns on Embodiment 1 of this invention. It is explanatory drawing for demonstrating another example of how to attach the heat exchanger tube to the sealing instrument in the manufacturing method of the heat exchanger which concerns on Embodiment 1 of this invention. It is explanatory drawing for demonstrating another example of how to attach the heat exchanger tube to the sealing instrument in the manufacturing method of the heat exchanger which concerns on Embodiment 1 of this invention. It is a figure which shows the state which provided the notch | incision in the plate-shaped member used as the fin with which the heat exchanger which concerns on Embodiment 1 of this invention is provided. It is a figure which shows the state which inserted the heat exchanger tube in the through-hole of the fin with which the heat exchanger which concerns on Embodiment 1 of this invention is equipped. It is a figure which shows the state which expanded the heat exchanger tube inserted in the through-hole of the fin with which the heat exchanger which concerns on Embodiment 1 of this invention is equipped. It is the schematic which showed typically an example of the shape of the edge part of the heat exchanger tube with which the heat exchanger which concerns on Embodiment 1 of this invention is equipped. It is the schematic which shows the state which expanded X area | region shown in FIG. It is a schematic block diagram which shows an example of the refrigerant circuit structure of the refrigerating cycle apparatus 100 which concerns on Embodiment 2 of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings as appropriate. In addition, in the following drawings including FIG. 1, the relationship of the magnitude | size of each structural member may differ from an actual thing. In addition, in the following drawings including FIG. 1, those given the same reference numerals are the same or correspond to this, and this is common to the whole text of the specification. Furthermore, the form of the component shown in the specification full text is an illustration to the last, and is not limited to these descriptions.

Embodiment 1
FIG. 1 is a schematic perspective view showing an example of the configuration of a heat exchanger according to Embodiment 1 of the present invention. Hereinafter, the heat exchanger according to the first embodiment is referred to as a heat exchanger 1A. FIG. 2 is a schematic side view showing an example of the heat exchanger 1A as viewed from the air flow direction. FIG. 3 is a schematic side view showing an example of the heat exchanger 1A as viewed from the flow direction of the refrigerant. An example of the heat exchanger 1A will be described based on FIGS. 1 to 3.

As shown in FIGS. 1 and 2, the heat exchanger 1A includes a plurality of fins 30A, a plurality of heat transfer pipes 20A, a header 40A, and an inter-row connecting member 45A. Specifically, the heat exchanger 1A is a heat exchanger having a two-row structure, and includes the upwind heat exchanger 41A, the downwind heat exchanger 42A, the upwind header 40A-1, the downwind header 40A-2, and , The inter-row connection member 45A. The windward header 40A-1 and the windward header 40A-2 may be collectively referred to as a header 40A. The upwind side heat exchanger 41A and the downwind side heat exchanger 42A are similarly configured. In the following, when the heat exchanger 1A is described, it is assumed that both the upwind side heat exchanger 41A and the downwind side heat exchanger 42A are described.

Further, as shown in FIG. 1, the windward header 40A-1 and the windward header 40A-2 are attached to the paper right side of the windward heat exchanger 41A and the paper right side of the windward heat exchanger 42A. Furthermore, as shown in FIG. 1, the inter-row connection member 45A is attached to the left side of the windward heat exchanger 41A in the drawing and the left side of the leeward heat exchanger 42A in the drawing. Thus, the heat exchanger 1A is produced.

The heat transfer tubes 20A are attached to the windward header 40A-1 at a predetermined interval (pitch P1). Similarly, the heat transfer tubes 20A are attached to the downwind side header 40A-2 at a predetermined interval (pitch P1).
The plurality of heat transfer tubes 20A are mounted to penetrate through the plurality of through holes 31A formed in the fins 30A, and intersect the fins 30A. As shown in FIG. 3, the heat transfer tube 20A is configured to have a circular cross section. The plurality of heat transfer tubes 20A are disposed at predetermined intervals in a step direction (vertical direction in the drawing) orthogonal to the flow direction of the refrigerant.
The distance in the direction of gravity of the heat transfer tubes 20A vertically adjacent to each other is constant at the pitch P2 of the adjacent through holes 31A of the fins 30A.
Further, the heat transfer tube 20A is made of aluminum or an aluminum alloy.

Although FIG. 2 and FIG. 3 show an example in which the number of heat transfer tubes 20A is ten, the number of heat transfer tubes 20A is not particularly limited. The symbols shown in FIGS. 1 to 3 are also used in the following drawings.
Further, a region where the through holes 31A of the fins 30A are formed is referred to as a heat transfer tube region 31R.
Further, a region which is both ends in the short direction of the fins 30A and in which the fins 30A are continuous in the longitudinal direction without being divided by the through holes 31A is referred to as a fin region 32R.

The fin 30A is formed of a rectangular plate-like member having a long side and a short side. The fins 30A have a pitch P1 in the longitudinal direction, and a plurality of through holes 31A are formed through the heat transfer pipe area 31R.
The fins 30A are made of aluminum or an aluminum alloy.
Further, although the through holes 31A have a circular shape corresponding to the cross sectional shape of the heat transfer tube 20A, the shape is not specified.
In the following description, the long side direction of the fin 30A is referred to as the longitudinal direction, and the short side direction is referred to as the short direction.

Another configuration of the heat exchanger according to Embodiment 1 of the present invention will be described. Another configuration of the heat exchanger according to the first embodiment is referred to as a heat exchanger 1B. FIG. 4 is a schematic perspective view showing an example of the configuration of the heat exchanger 1B. FIG. 5 is a schematic side view showing an example of the heat exchanger 1B as viewed from the flow direction of the refrigerant. FIG. 6 is a schematic cross-sectional view showing a cross section of the heat transfer tube 20B which constitutes the heat exchanger 1B. FIG. 7 is a schematic front view of the fins 30B constituting the heat exchanger 1B. FIG. 8 is a schematic side view of the fins 30B constituting the heat exchanger 1B. FIG. 9 is a schematic top view of the fins 30B constituting the heat exchanger 1B. An example of the heat exchanger 1B will be described based on FIGS. 4 to 9.

As shown in FIG. 4, the heat exchanger 1B is provided with a plurality of plate-like fins 30B, a plurality of heat transfer tubes 20B, a header 40B, and an inter-row connecting member 45B. Specifically, the heat exchanger 1B is a heat exchanger having a two-row structure, and includes the upwind heat exchanger 41B, the downwind heat exchanger 42B, the upwind header 40B-1, the downwind header 40B-2, and , And inter-row connection member 45B. The windward header 40B-1 and the windward header 40B-2 may be collectively referred to as a header 40B. The upwind side heat exchanger 41B and the downwind side heat exchanger 42B are similarly configured. In the following, when the heat exchanger 1B is described, it is assumed that both the upwind side heat exchanger 41B and the downwind side heat exchanger 42B are described.

Further, as shown in FIG. 4, the windward header 40B-1 and the windward header 40B-2 are attached to the paper right side of the windward heat exchanger 41B and the paper right side of the windward heat exchanger 42B. Further, as shown in FIG. 4, the inter-row connecting member 45B is attached to the left side of the windward side heat exchanger 41B as viewed in the drawing and the left side of the windward side heat exchanger 42B as viewed. Thus, the heat exchanger 1B is produced.

A plurality of tube attachment portions 40Ba to which the heat transfer tubes 20B are attached are formed in the windward header 40B-1 at a predetermined interval (pitch P1). Similarly, in the downwind side header 40B-2, a plurality of tube attachment portions 40Bb to which the heat transfer tubes 20B are attached are formed at a predetermined interval (pitch P1).

The plurality of heat transfer tubes 20B are attached to penetrate through the plurality of through holes 31B formed in the fins 30B, and intersect with the fins 30B. As shown in FIG. 6, the heat transfer tube 20B is configured to have a flat cross-sectional shape. The plurality of heat transfer tubes 20B are arranged at predetermined intervals in a step direction (vertical direction in the drawing) orthogonal to the flow direction of the refrigerant.
The distance in the direction of gravity of the heat transfer tubes 20B vertically adjacent to each other is constant at the pitch P2 of the adjacent through holes 31B of the fins 30B.
Further, the heat transfer tube 20B is made of aluminum or an aluminum alloy.

Although FIG. 5 shows an example in which the number of heat transfer tubes 20B is eight, the number of heat transfer tubes 20B is not particularly limited. The symbols shown in FIG. 4 to FIG. 9 are similarly used in the following drawings.
Further, a region where the through holes 31B of the fins 30B are formed is referred to as a heat transfer tube region 31R.
Furthermore, regions at both ends in the short direction of the fins 30B and not divided by the through holes 31B and in which the fins 30B extend in the longitudinal direction are referred to as fin regions 32R.

As shown in FIG. 7, the fins 30 </ b> B are formed of rectangular plate members having long sides and short sides. The fins 30B have a pitch P1 in the longitudinal direction, and a plurality of through holes 31B are formed through the heat transfer tube area 31R. When the through hole 31B is formed, the peripheral portion of the through hole 31B functions as a fin collar. The fin collar in the longitudinal direction of the through hole 31B is referred to as a first fin collar 311, and the fin collar in the lateral direction of the through hole 31B is referred to as a second fin collar 312. By doing so, as shown in FIG. 8 and FIG. 9, the fin pitch P3 which is an interval of the plurality of fins 30B is defined by the second fin collar 312.

FIG. 7 shows a state in which the through holes 31B have a rectangular shape in which the short direction of the fins 30B is a long side and the longitudinal direction of the fins 30B is a short side. The specific shape of the through hole 31B is not specified, and the through hole 31B may have any shape as long as the heat transfer tube 20B can be inserted.
The fins 30B are made of aluminum or an aluminum alloy.
Moreover, although the through hole 31B has a rectangular shape, the shape is not specified.
In the following description, the long side direction of the fin 30B is referred to as the longitudinal direction, and the short side direction is referred to as the short direction.

The heat transfer tube 20B will be described in detail.
As shown in FIG. 6, the heat transfer tube 20B is formed in a shape in which the lateral width (the length in the cross sectional major axis direction) is larger than the longitudinal width (the length in the cross sectional minor axis direction). The plurality of heat transfer tubes 20B have the direction of the major axis of the cross section as the flow direction of the fluid flowing between the fins 30B, and are arranged at predetermined intervals in the step direction (vertical direction in the drawing) orthogonal to the flow direction. In the following description, the cross-sectional long axis of the heat transfer tube 20B, that is, a portion extending in the width direction (short direction) of the fins 30B may be referred to as the width direction of the heat transfer tube 20B.

The heat transfer tube 20B shown in FIG. 6 will be described by way of example in the case of a flat tube having a flat width (length in the cross sectional major axis direction) larger than the vertical width (length in the cross axis minor axis direction). It is not necessary for the heat transfer tube 20B to be strictly formed in a flat shape, as long as the heat transfer tube 20B has a shape having a larger horizontal width than the vertical width.

As shown in FIG. 6, the heat transfer tube 20B includes an upper surface 21a including an upper portion, a lower surface 21c including a lower portion, and one side portion 21b including one end in the width direction (the end on the right side in FIG. 6); It has the other side 21 d including the other end in the width direction (the end on the left side in the drawing of FIG. 6). The upper surface 21a, the lower surface 21c, the one side portion 21b, and the other side portion 21d are collectively referred to as an outer wall 21.
Although FIG. 6 shows an example in which the upper surface 21a and the lower surface 21c are parallel to each other, at least one of the upper surface 21a and the lower surface 21c may be inclined so as not to be parallel to each other. In addition, the cross-sectional shape of the heat transfer tube 20B may be elliptical or the like.

The heat transfer tube 20B also has a plurality of inner walls 22. The plurality of inner walls 22 are formed to partition the internal space of the heat transfer tube 20B. By forming the inner wall 22 inside the heat transfer tube 20B, a plurality of inner holes 23 partitioned in the inner wall 22 will be formed. The inner hole 23 functions as an internal flow path through which the refrigerant flows.
A groove or a slit may be formed on the inner surface of the heat transfer tube 20B including the inner wall 22. As a result, the contact area with the refrigerant flowing through the inner hole 23 is increased, and the heat exchange efficiency is improved.

The header 40A and the header 40B will be described in detail. The header 40A and the header 40B are collectively described as a header 40. FIG. 10 is a schematic perspective view showing a configuration example of the header 40 provided in the heat exchanger according to the first embodiment. FIG. 11 is a schematic cross-sectional view showing an example of the cross-sectional configuration of the header 40 provided in the heat exchanger according to the first embodiment. FIG. 12 is a schematic cross-sectional view showing another example of the cross-sectional configuration of the header 40 provided in the heat exchanger according to the first embodiment.

In addition, although it demonstrates based on the heat exchanger 1B here, it is applicable to the heat exchanger 1A similarly. In the following description, the heat transfer pipe 20A and the heat transfer pipe 20B may be collectively referred to as the heat transfer pipe 20. Similarly, the fins 30A and the fins 30B may be collectively referred to as fins 30. The through holes 31A and the through holes 31B may be collectively referred to as the through holes 31 in some cases.

As the header 40, as shown in FIG. 10 and FIG. 11, a cylindrical header 40-1 communicating with the inside can be adopted. The cylindrical header 40-1 has a cylindrical portion 46 in which an internal space 44 serving as a flow passage of the heat exchange fluid is formed. That is, the cylindrical header 40-1 is a hollow header. The outer shell of the cylindrical portion 46 is formed by the outer wall portion 41. Further, in the outer wall portion 41, a plurality of heat transfer pipe connection portions 43 to which the heat transfer pipe 20B is connected are formed. The shape of the heat transfer tube connection portion 43 is such that the heat transfer tube 20B can be directly connected.

When a circular pipe joint is connected to the end of the heat transfer pipe 20B on the header 40 side, the heat transfer pipe connection portion 43 may have a circular shape. That is, the shape of the heat transfer tube connection part 43 should just be a shape according to the shape of the heat transfer tube to connect. The circular pipe joint will be described with reference to FIG.

Here, the cross-sectional long axis of the heat transfer tube 20B is da, the number of the inner holes 23 is n, the thickness of the outer wall 21 is tp, and the required withstand pressure is P.
The inner diameter of the cylindrical header 40-1 is dh, the thickness of the outer wall portion 41 is th, and the tensile strength is σ.
At this time, the cylindrical header 40-1 is configured such that dh / th is 2σ / {P * (da / n / tp-1)} or more.
By doing this, the thickness of the outer wall portion 41 of the cylindrical header 40-1 can be made smaller compared to the inner diameter of the cylindrical header 40-1, and the material cost can be reduced accordingly.
The inner diameter of the cylindrical header 40-1 means the inner diameter of the cylindrical portion 46.

Further, as the header 40, as shown in FIG. 12, a laminated header 40-2 having a plurality of plate-like bodies 90 can be adopted. The plate-like body 90 is formed by alternately laminating a first plate-like member 91a to a first plate-like member 91d to be a bear member and a second plate-like member 92a to a second plate-like member 92d to be a clad material. It is formed. On the outermost side in the stacking direction of the plate-like body 90, the first plate-like member 91a and the first plate-like member 91e are stacked.
Hereinafter, the first plate-like member 91a to the first plate-like member 91e may be collectively referred to as a plurality of first plate-like members 91. Similarly, the second plate-like member 92a to the second plate-like member 92d may be collectively referred to as a plurality of second plate-like members 92.

The plurality of first plate members 91 are made of aluminum. The brazing material is not applied to the plurality of first plate members 91. In each of the plurality of first plate-like members 91, a through hole serving as the distribution / merging flow path 65 is formed. The through holes penetrate the front and back of the plurality of first plate members 91. Through the plurality of first plate members 91 and the plurality of second plate members 92 being stacked, the through holes formed in the plurality of first plate members 91 form a flow passage for the heat exchange fluid. Function as a part of the distribution / merging channel 65.

The plurality of second plate-like members 92 are made of aluminum, and are formed thinner than the plurality of first plate-like members 91. A brazing material is applied to at least the front and back surfaces of the plurality of second plate members 92. Each of the plurality of second plate-like members 92 is formed with a through hole serving as the distribution and merging channel 65. The through holes penetrate the front and back of the plurality of second plate members 92. The through holes formed in the second plate-like members 92 with the number of hooks formed by stacking the plurality of first plate-like members 91 and the plurality of second plate-like members 92 are flow channels for the heat exchange fluid It functions as a part of the distribution / merging channel 65 which

The connection pipe 61a is connected to the through hole formed in the first plate-like member 91a. A nozzle or the like may be provided on the surface of the first plate member 91 a on the inflow side of the refrigerant, and the connection pipe 61 a may be connected via the nozzle or the like. Further, the inner peripheral surface of the through hole formed in the first plate-like member 91a is shaped to fit with the outer peripheral surface of the connection pipe 61a, and the connection pipe 61a is directly connected without using a die or the like. Good.

The connection pipe 62a is connected to the through hole formed in the first plate member 91e. A nozzle or the like may be provided on the surface of the first plate-like member 91 e on which the refrigerant flows, and the connection pipe 62 a may be connected via the nozzle or the like. The inner peripheral surface of the through hole formed in the first plate-like member 91e is shaped to fit with the outer peripheral surface of the connection pipe 62a, and the connection pipe 62a may be directly connected without using a base or the like. Good. The connection piping 62a may be connected by inserting the connection piping 62a so as to reach the through hole of the first plate-like member 91d.

The through holes formed in the first plate-like member 91 b and the first plate-like member 91 c are formed to pass through in a Z-shaped flow passage cross section.
In addition, a flow-path cross section is a cross section which cut the flow path in the direction orthogonal to the flow of the fluid.

When the first plate member 91 and the second plate member 92 are stacked, a through hole formed in the first plate member 91 and a through hole formed in the second plate member 92, Communicate with each other to form the distribution / merging channel 65. That is, when the first plate-like member 91 and the second plate-like member 92 are stacked, the adjacent through holes communicate with each other, and the first plate-like member 91 or the first plate-like member 91 It is closed by the two plate-like member 92, and the distribution and merging channel 65 is formed.
Although FIG. 12 illustrates the case where the distribution / merging flow channel 65 has four fluid outlet portions for one fluid inlet portion, the number of branches is limited to four. is not.

The flow of the refrigerant in the upper stage branch portion 60a when the refrigerant flows in from the connection pipe 61a will be described.
As shown in FIG. 12, the refrigerant having flowed through the connection pipe 61a flows into the inside of the upper stage branch portion 60a as a fluid inlet portion through the through hole of the first plate-like member 91a. The refrigerant flows into the through hole of the second plate-like member 92a.

The refrigerant that has flowed into the through hole of the second plate member 92a flows into the center of the through hole of the first plate member 91b. The refrigerant that has flowed into the center of the through hole of the first plate member 91b hits the surface of the second plate member 92d stacked adjacent to it and branches, and flows to the end of the through hole of the first plate member 91b. The refrigerant reaching the end of the through hole of the first plate member 91b passes through the through hole of the second plate member 92b and flows into the center of the through hole of the first plate member 91c.

The refrigerant that has flowed into the center of the through hole of the first plate member 91c strikes the surface of the adjacent second laminated plate member 92c and branches, and flows to the end of the through hole of the first plate member 91c. The refrigerant reaching the end of the through hole of the first plate member 91c passes through the through hole of the second plate member 92c and flows into the through hole of the first plate member 91d. The refrigerant that has flowed into the through hole of the first plate member 91d passes through the through hole of the second plate member 92d, and is transferred to the heat transfer pipe 20B through the connection pipe 62a located in the through hole of the first plate member 91e. To flow.

As described above, by forming the header 40 as the stacked header 40-2, uniformity of distribution of the refrigerant in the header 40 can be improved.

Next, a method of manufacturing the heat exchanger 1B according to the first embodiment of the present invention will be described. FIG. 13 is a flow chart schematically showing the steps of the method of manufacturing the heat exchanger 1B. FIG. 14 is an explanatory view for explaining an example of how to attach the heat transfer tube to the sealing device 70 in the method of manufacturing the heat exchanger 1B. The manufacturing method of the heat exchanger 1B is demonstrated based on FIG.13 and FIG.14. In addition, although the manufacturing method of the heat exchanger 1B is demonstrated here, it is applicable to the heat exchanger 1A similarly.

As shown in FIG. 13, the method of manufacturing the heat exchanger 1B is roughly divided into two steps (a first step 51 and a second step 52). In FIG. 13, the preparation process 50 is illustrated as a pre-process of the first process 51.

The preparation step 50 is a step of inserting the heat transfer tube 20B into the through hole 31B of the fin 30B and performing temporary assembly of the heat exchanger 1B. In the preparation step 50, the plurality of heat transfer pipes 20B are attached in parallel to the plurality of fins 30B arranged in parallel at the fin pitch P3. In this state, the first step 51 is performed.

The first step 51 is a step of expanding the heat transfer tube 20B by applying pressure to the inside of the heat transfer tube 20B so as to push and spread the heat transfer tube 20B from the inside. First, after the preparation step 50, the high pressure gas container 60 and the sealing device 70 are attached to both ends of the heat transfer tube 20B in the direction in which the fins 30B are arranged. Thus, the high pressure gas is caused to flow into the heat transfer tube 20B. The high pressure gas acts to push and spread the heat transfer pipe 20B from the inside of the heat transfer pipe 20B, and the heat transfer pipe 20B is expanded. That is, in the first step 51, the plurality of heat transfer tubes 20B are expanded without the header 40.

A method of attaching the heat transfer tube 20B to the sealing device 70 will be described with reference to FIG. The sealing device 70 has an insertion portion 71 into which the heat transfer tube 20B is inserted. The insertion portion 71 is formed with a recess 72 which is recessed toward the outer periphery. On the outer periphery of the end of the heat transfer tube 20B on the sealing device 70 side, a convex mounting portion 24 protruding outward is provided. Then, when the heat transfer tube 20B is attached to the sealing device 70, the mounting portion 24 of the heat transfer tube 20B is fitted into the recess 72 of the sealing device 70. By this, it is possible to fix the heat transfer tube 20B to the sealing device 70.

However, the specific configuration of the sealing device 70 is not specified, as long as the heat transfer tube 20B can be fixed. In addition, about the modification of the instrument 70 for sealing, it demonstrates in FIG.15 and FIG.16.

Refer again to FIG. The second step 52 is a step of joining the header 40 to the expanded plurality of heat transfer tubes 20B by brazing or the like.
When the heat transfer tube 20B is expanded in the first step 51, the heat transfer tube 20B may be brought into close contact with the fins 30B, but in the second step 52, the heat transfer tube 20B and the header 40 are brazed simultaneously Both the heat pipe 20B and the fins 30B may be brazed. In this case, a brazing material may be applied or laminated on the surface of at least one of the heat transfer tube 20B and the fins 30B, and the heat transfer tube 20B and the fins 30B may be brazed in the second step 52.

In any case, the adhesion between the heat transfer tube 20B and the fins 30B can be enhanced, and the performance of the heat exchanger 1B can be improved. Note that the heat transfer tube 20B may be in close contact with the fins 30B by any one of the means, or the heat transfer tube 20B may be in close contact with the fins 30B by both means.

<Modification of Sealing Device 70 Used in Manufacturing Method of Heat Exchanger 1B>
FIG. 15 is an explanatory diagram for explaining another example of how to attach the heat transfer tube to the sealing device 70 in the method of manufacturing the heat exchanger 1B. FIG. 16 is an explanatory view for explaining still another example of how the heat transfer tube is attached to the sealing device 70 in the method of manufacturing the heat exchanger 1B. Based on FIG.15 and FIG.16, the modification of the instrument 70 for sealing used by the manufacturing method of the heat exchanger 1B is demonstrated.

In FIG. 14, the heat transfer tube 20B is attached to the sealing device 70 by directly inserting the heat transfer tube 20B into the sealing device 70 as an example. In FIG. 15, the heat transfer tube 20B is attached to the sealing device 70 via the circular pipe joint 80, instead of directly inserting the heat transfer tube 20B into the sealing device 70.

The circular pipe joint 80 is for connecting the heat transfer pipe 20B and the sealing device 70. Specifically, the circular pipe joint 80 converts the cross-sectional shape of the heat transfer tube 20B into a shape that can be connected to the sealing device 70. Here, the case where the circular pipe joint 80 connects the heat transfer pipe 20B having a flat cross-sectional shape to a sealing device 70 to which a pipe having a circular cross-sectional shape can be connected is shown as an example.

The sealing device 70 is configured to press the circular pipe portion from the inner wall side and the outer wall side by the insertion portion 71 with respect to the circular pipe joint 80 connected to the heat transfer pipe 20B. The circular pipe portion of the circular pipe joint 80 is a portion having a circular cross section which is inserted into the sealing device 70 of the circular pipe joint 80. The heat transfer tube 20B can be attached to the sealing device 70 by pressing this portion with the sealing device 70.

By using the sealing device 70 having such a configuration, in the second step 52, the circular tube portion of the circular pipe joint 80 is fixed more firmly from the inside and the outside by the sealing device 70 and the circular pipe joint 80. As it can be done, the degree of sealing is increased, and the leakage of high pressure gas can be further suppressed. Therefore, it is possible to improve manufacturing safety while improving the pressurizing efficiency in the second step 52. Moreover, highly reliable heat exchanger 1B can be manufactured efficiently. Thus, the reliability of the created heat exchanger 1B is improved.

The circular pipe joint 80 corresponds to the “joint” of the present invention.
However, even when the heat transfer tube 20A is used, the heat transfer tube 20A may be attached to the sealing device 70 through a joint. In this case, the configuration of the joint corresponds to the heat transfer tube 20A and the sealing device 70.

In FIG. 16, as in FIG. 14, the heat transfer tube 20B is attached to the sealing device 70 by directly inserting the heat transfer tube 20B into the sealing device 70. In FIG. 14, the case where the attachment portion 24 is provided to the heat transfer tube 20B has been described as an example, but in FIG. 16, a part of the inner wall 22 of the end of the heat transfer tube 20B on the sealing device 70 side is removed There is.

The heat transfer tube 20 B is inserted into the insertion portion 71 of the sealing device 70. The sealing device 70 is configured to press the heat transfer tube 20B from the inner wall side and the outer wall side by the insertion portion 71 in a region where the inner wall 22 of the heat transfer tube 20B does not exist. By this, it is possible to fix the heat transfer tube 20B to the sealing device 70.

By using the sealing device 70 having such a configuration, in the second step 52, the sealing device 70 enables the region where the inner wall 22 of the heat transfer tube 20B is not present to be fixed more firmly from the inside and the outside. Therefore, the degree of sealing is increased, and the leakage of high pressure gas can be further suppressed. Therefore, it is possible to improve manufacturing safety while improving the pressurizing efficiency in the second step 52. Moreover, highly reliable heat exchanger 1B can be manufactured efficiently. Thus, the reliability of the created heat exchanger 1B is improved.

<Modification Example of Method of Joining Heat Transfer Tube 20B and Fins 30B>
FIG. 17 is a view showing a state in which the plate-like member to be the fins 30B provided in the heat exchanger 1B is cut. FIG. 18 is a view showing a state in which the heat transfer pipe 20B is inserted into the through hole 31B of the fin 30B provided in the heat exchanger 1B. FIG. 19 is a view showing a state in which the heat transfer pipe 20B inserted into the through hole 31B of the fin 30B provided in the heat exchanger 1B is expanded. An example of a method of joining the heat transfer tube 20B and the fins 30B will be described based on FIGS. 17 to 19. FIG. In addition, the plate-shaped member used as the fin 30B is shown as the plate-shaped member 30a.

As described above, the peripheral portion of the through hole 31B functions as a fin collar. First, as shown in FIG. 17, a cut is provided in a portion to be the heat transfer tube region 31R of the plate-like member 30a. Specifically, a notch 311a is provided at the boundary of the portion where the first fin collar 311 of the plate member 30a is cut and raised. Moreover, the notch 312a is provided in the boundary of the part which cuts and raises the 2nd fin collar 312 of the plate-shaped member 30a.

After the cuts 311a and the cuts 312a are provided, as shown in FIG. 18, the plate-like member 30a is bent in one direction via the cuts 311a and the cuts 312a. The figure shows a state in which the plate-like member 30a is bent to the front side of the drawing sheet. By doing this, the peripheral portion of the through hole 31B is cut and raised like a tongue. The tongue-like portion cut and raised in the longitudinal direction of the fin 30B through the notch 311a functions as the first fin collar 311. The tongue-like portion cut and raised in the short direction of the fin 30 B through the notch 312 a functions as the second fin collar 312. And the part by which the plate-shaped member 30a was open | released functions as a through-hole 31B.

The first fin collar 311 and the first fin collar 311 have a length L1 in the short direction of the fins 30B of the first fin collar 311 greater than the length L2 in the longitudinal direction of the fins 30B of the second fin collar 312. Two fin collars 312 are formed. That is, the cut 311a and the cut 312a are formed so as to satisfy the relationship of length L1> length L2.
Further, the gap length L3 between the second fin collar 312 and the heat transfer pipe 20B inserted into the through hole 31B is the gap length L4 between the first fin collar 311 and the heat transfer pipe 20B inserted into the through hole 31B. It is set larger than.

After forming the through hole 31B, as shown in FIG. 18, the heat transfer pipe 20B is inserted into the through hole 31B. Next, as shown in FIG. 19, the heat transfer pipe 20B is expanded. In this way, when the heat transfer tube 20B is expanded in the first step 51, the first fin collar 311 is in close contact with the surface of the outer wall 21 in the longitudinal direction of the cross section of the heat transfer tube 20B.

By bonding the heat transfer tube 20B to the fins 30B in this manner, the first fin collar 311 can ensure the adhesion to the fins 30B on the longitudinal surface of the heat transfer tube 20B, and improve the heat exchange efficiency. Can. Further, the heat transfer pipe 20B can be expanded by the second fin collar 312 while maintaining the distance between the adjacent fins 30B, and the reliability of the heat exchanger 1B can be secured. Thus, the reliability of the created heat exchanger 1B is improved.
The longitudinal surface of the heat transfer tube 20B means the surface of the outer wall 21 of the heat transfer tube 20B in the flow direction of the refrigerant.

FIG. 20 is a schematic view schematically showing an example of the shape of the end portion of the heat transfer tube 20B provided in the heat exchanger 1B. FIG. 21 is a schematic view showing a state in which the cross section of the X region shown in FIG. 20 is enlarged. Based on FIG. 20 and FIG. 21, another example of the joining method of the heat exchanger tube 20B and the fin 30B is demonstrated. In addition, in FIG. 20, the state at the time of inserting the heat exchanger tube 20B in the fin 30B is illustrated.

In the first step 51, the plurality of heat transfer pipes 20B are attached in parallel to the through holes 31B of the plurality of fins 30B arranged in parallel at the fin pitch P3. In FIG. 20, one fin 30B is illustrated as an example. At this time, it is assumed that the end on the insertion side of the heat transfer tube 20B (the end on the left side in the drawing) is caught on the periphery of the through hole 31B. Therefore, it is preferable to make the end on the insertion side of the heat transfer tube 20B into a shape that is less likely to get caught on the periphery of the through hole 31B.

Specifically, a chamfered portion 21A is formed on the outer wall 21 at the insertion-side end of the heat transfer tube 20B to improve the insertability of the heat transfer tube 20B into the fin 30B. The chamfered portion 21A is formed such that an angle θ between a straight line L4 extending from the tube inner point A to the tube outer end B of the heat transfer tube 20B and the longitudinal direction (L5) of the fin 30B is an acute angle.

Since the angle θ is an acute angle, the insertability of the heat transfer tube 20B into the fins 30B can be improved. That is, when the heat transfer tubes 20B are inserted into the fins 30B, it is possible to prevent the heat transfer tubes 20B and the fins 30B from contacting each other and damaging each other. In addition, since the end on the insertion side of the heat transfer tube 20B is reduced, the insertion to the fin 30B is facilitated. Therefore, it is possible to improve manufacturing safety. Moreover, highly reliable heat exchanger 1B can be manufactured efficiently. Thus, the reliability of the created heat exchanger 1B is improved.

<The effect of the heat exchanger according to the first embodiment and the method of manufacturing the heat exchanger>
In the heat exchanger according to the first embodiment, the header 40 is configured such that dh / th is 2σ / {P * (da / n / tp-1)} or more. Therefore, in the heat exchanger according to the first embodiment, the thickness of the outer wall portion 41 of the header 40 can be smaller than the inner diameter of the header 40. Therefore, according to the heat exchanger according to the first embodiment, it is possible to reduce the material cost by which the thickness of the outer wall portion 41 of the header 40 can be reduced.

In the method of manufacturing the heat exchanger according to the first embodiment, after the heat transfer tube 20 is joined to the fin 30, the heat transfer tube 20 is brazed to the header 40 having a fluid flow passage inside. That is, in the method of manufacturing the heat exchanger according to the first embodiment, the pressurizing path can be sealed at the time of high-pressure gas supply without connecting the heat transfer pipe 20 to the header 40. Therefore, according to the method of manufacturing a heat exchanger according to the first embodiment, it is possible to expand the plurality of heat transfer tubes 20 without the header 40, and the header 40 has a pressure resistance equal to or higher than that of the heat transfer tubes 20. There is no need to have That is, the thickness of the outer wall portion 41 can be made thinner than the inner space 44 of the header 40. Thereby, the reliability of the heat exchanger according to the first embodiment can be secured while suppressing the weight increase of the heat exchanger according to the first embodiment.

In the method of manufacturing the heat exchanger according to the first embodiment, when the header 40 and the heat transfer tube 20 are brazed, the heat transfer tube 20 and the fin 30 are also brazed, so the adhesion between the heat transfer tube 20 and the fin 30 Can enhance the performance of the heat exchanger.

In the method of manufacturing the heat exchanger according to the first embodiment, the length L1 of the first fin collar 311 is larger than the length L2 of the second fin collar 312, and the gap length L3 is the gap length L4. It is set larger than. Therefore, according to the method of manufacturing the heat exchanger according to the first embodiment, the adhesion between the heat transfer tube 20 and the fins 30 can be enhanced while maintaining the distance between the adjacent fins 30, and the performance of the heat exchanger can be improved. Can be improved.

In the method of manufacturing the heat exchanger according to the first embodiment, since the heat transfer tube 20 is fixed to the sealing device 70 by fitting the attachment portion 24 of the heat transfer tube 20 into the recess 72, the heat transfer tube 20 is sealed. It can be firmly fixed by the device 70, the degree of sealing is increased, and leakage of high pressure gas can be further suppressed. Therefore, according to the method of manufacturing a heat exchanger according to the first embodiment, it is possible to improve manufacturing safety while improving the pressurizing efficiency in the second step 52. In addition, a highly reliable heat exchanger can be manufactured efficiently.

In the method of manufacturing the heat exchanger according to the first embodiment, the circular pipe portion of the circular pipe joint 80 is pressed down by the insertion portion 71 from the inner wall side and the outer wall side, so that the circular pipe joint 80 is reinforced by the sealing device 70. As it can be done, the degree of sealing is increased, and the leakage of high pressure gas can be further suppressed. Therefore, according to the method of manufacturing a heat exchanger according to the first embodiment, it is possible to improve manufacturing safety while improving the pressurizing efficiency in the second step 52. In addition, a highly reliable heat exchanger can be manufactured efficiently.

In the method of manufacturing the heat exchanger according to the first embodiment, the heat transfer tube 20 is inserted into the sealing device 70 by the region where the inner wall 22 of the heat transfer tube 20 is not provided being pressed from the inner wall side and the outer wall side by the insertion portion 71. It is fixed.
Therefore, since the heat transfer tube 20 can be firmly fixed by the sealing device 70, the degree of sealing can be increased and leakage of high pressure gas can be further suppressed. Therefore, according to the method of manufacturing a heat exchanger according to the first embodiment, it is possible to improve manufacturing safety while improving the pressurizing efficiency in the second step 52. In addition, a highly reliable heat exchanger can be manufactured efficiently.

In the method of manufacturing the heat exchanger according to the first embodiment, since the chamfered portion 21A having an acute angle θ is formed on the outer wall 21 at one end of the heat transfer tube 20, the heat transfer tube 20 and the fins 30 and Can be easily inserted into the fins 30 of the heat transfer tube 20 while suppressing the contact of the heat transfer tube 20.

Second Embodiment
A refrigeration cycle apparatus 100 according to Embodiment 2 of the present invention will be described. FIG. 22 is a schematic configuration diagram showing an example of the refrigerant circuit configuration of the refrigeration cycle apparatus 100. As shown in FIG. The case where the refrigeration cycle apparatus 100 is an air conditioner will be described as an example. In FIG. 22, the flow of the refrigerant during the cooling operation is indicated by a broken arrow, and the flow of the refrigerant during the heating operation is indicated by the solid arrow.

<Configuration of Refrigeration Cycle Apparatus 100>
As shown in FIG. 22, the refrigeration cycle apparatus 100 includes the compressor 101, the first heat exchanger 102, the first fan 105, the expansion device 103, the second heat exchanger 104, the second fan 106, and the flow path switching. A device 107 is provided. The compressor 101, the first heat exchanger 102, the expansion device 103, the second heat exchanger 104, and the flow path switching device 107 are connected by the refrigerant pipe 110 to form a refrigerant circuit.
Note that at least one of the first heat exchanger 102 and the second heat exchanger 104 is the heat exchanger according to the first embodiment.

The compressor 101 compresses a refrigerant. The refrigerant compressed by the compressor 101 is discharged and sent to the flow path switching device 107. The compressor 101 can be configured by a rotary compressor, a scroll compressor, a screw compressor, a reciprocating compressor, or the like.

The first heat exchanger 102 functions as a condenser during heating operation and functions as an evaporator during cooling operation. The first heat exchanger 102 is a finned tube type heat exchanger, a microchannel heat exchanger, a shell and tube type heat exchanger, a heat pipe type heat exchanger, a double pipe type heat exchanger, or a plate heat exchanger. And so on. When the heat exchanger according to the first embodiment is applied as the first heat exchanger 102, the first heat exchanger 102 is a finned tube heat exchanger.

The expansion device 103 expands and reduces the pressure of the refrigerant having passed through the first heat exchanger 102 or the second heat exchanger 104. The expansion device 103 may be configured by an electric expansion valve or the like capable of adjusting the flow rate of the refrigerant. As the expansion device 103, not only a motorized expansion valve but also a mechanical expansion valve employing a diaphragm in a pressure receiving portion, a capillary tube or the like can be applied.

The second heat exchanger 104 functions as an evaporator during heating operation and functions as a condenser during cooling operation. The first heat exchanger 102 is a finned tube type heat exchanger, a microchannel heat exchanger, a shell and tube type heat exchanger, a heat pipe type heat exchanger, a double pipe type heat exchanger, or a plate heat exchanger. And so on. When the heat exchanger according to the first embodiment is applied as the second heat exchanger 104, the second heat exchanger 104 is a finned tube heat exchanger.

The flow path switching device 107 switches the flow of the refrigerant in the heating operation and the cooling operation. That is, the flow path switching device 107 is switched to connect the compressor 101 and the first heat exchanger 102 during heating operation, and connects the compressor 101 and the second heat exchanger 104 during cooling operation. It is switched. The flow path switching device 107 may be configured by a four-way valve. However, a combination of a two-way valve or a three-way valve may be employed as the flow path switching device 107.

The first fan 105 is attached to the first heat exchanger 102 and supplies air, which is a heat exchange fluid, to the first heat exchanger 102.
The second fan 106 is attached to the second heat exchanger 104 and supplies air, which is a heat exchange fluid, to the second heat exchanger 104.

<Operation of Refrigeration Cycle Apparatus 100>
Next, the operation of the refrigeration cycle apparatus 100 will be described along with the flow of the refrigerant. Here, the operation of the refrigeration cycle apparatus 100 will be described by taking an example where the heat exchange fluid is air and the heat exchange fluid is a refrigerant. The operation of the refrigeration cycle apparatus 100 will be described assuming that the first heat exchanger 102 cools or heats the air in the air-conditioning target space. In addition, the flow of the refrigerant | coolant at the time of air_conditionaing | cooling operation is shown by the broken line arrow of FIG. Moreover, the flow of the refrigerant | coolant at the time of heating operation is shown by the continuous line arrow in FIG.

First, the cooling operation performed by the refrigeration cycle apparatus 100 will be described.
As shown in FIG. 22, when the compressor 101 is driven, the refrigerant in a high temperature / high pressure gas state is discharged from the compressor 101. Hereinafter, the refrigerant flows according to the broken arrow. The high temperature / high pressure gas refrigerant (single phase) discharged from the compressor 101 flows into the second heat exchanger 104 functioning as a condenser via the flow path switching device 107. In the second heat exchanger 104, heat exchange is performed between the inflowing high-temperature and high-pressure gas refrigerant and the air supplied by the second fan 106, and the high-temperature and high-pressure gas refrigerant is condensed to a high pressure liquid. It becomes a refrigerant (single phase).

The high-pressure liquid refrigerant delivered from the second heat exchanger 104 is converted by the expansion device 103 into a two-phase refrigerant of low-pressure gas refrigerant and liquid refrigerant. The two-phase refrigerant flows into the first heat exchanger 102 that functions as an evaporator. In the first heat exchanger 102, heat exchange is performed between the inflowing two-phase refrigerant and the air supplied by the first fan 105, and the liquid refrigerant in the two-phase refrigerant is evaporated to evaporate. It is a low pressure gas refrigerant (single phase). By this heat exchange, the air conditioning target space is cooled.

The low-pressure gas refrigerant sent from the first heat exchanger 102 flows into the compressor 101 via the flow path switching device 107, is compressed and becomes a high-temperature and high-pressure gas refrigerant, and is discharged again from the compressor 101. Hereinafter, this cycle is repeated.

Next, the heating operation performed by the refrigeration cycle apparatus 100 will be described.
As shown in FIG. 22, when the compressor 101 is driven, the refrigerant in a high temperature / high pressure gas state is discharged from the compressor 101. Hereinafter, the refrigerant flows according to the solid arrow. The high temperature / high pressure gas refrigerant (single phase) discharged from the compressor 101 flows into the first heat exchanger 102 functioning as a condenser via the flow path switching device 107. In the first heat exchanger 102, heat exchange is performed between the inflowing high temperature / high pressure gas refrigerant and the air supplied by the first fan 105, and the high temperature / high pressure gas refrigerant is condensed to a high pressure It becomes a refrigerant (single phase). By this heat exchange, the air conditioning target space is heated.

The high-pressure liquid refrigerant delivered from the first heat exchanger 102 is converted by the expansion device 103 into a two-phase refrigerant of low-pressure gas refrigerant and liquid refrigerant. The two-phase refrigerant flows into the second heat exchanger 104 which functions as an evaporator. In the second heat exchanger 104, heat exchange is performed between the inflowing two-phase refrigerant and the air supplied by the second fan 106, and the liquid refrigerant in the two-phase refrigerant is evaporated to evaporate. It is a low pressure gas refrigerant (single phase).

The low-pressure gas refrigerant sent from the second heat exchanger 104 flows into the compressor 101 via the flow path switching device 107, is compressed and becomes a high-temperature and high-pressure gas refrigerant, and is discharged again from the compressor 101. Hereinafter, this cycle is repeated.

<Effect Performed by Refrigerating Cycle Apparatus 100 According to Second Embodiment>
Since the refrigeration cycle apparatus 100 according to the second embodiment uses the heat exchanger according to the first embodiment as at least one of the first heat exchanger 102 and the second heat exchanger 104, the reliability in the heat exchanger is obtained. It is possible to improve the quality and reduce the cost of the header 40.

1A heat exchanger, 1B heat exchanger, 20A heat transfer tube, 20B heat transfer tube, 21 outer wall, 21A chamfered portion, 21a upper surface, 21b one side, 21c lower surface, 21d other side, 22 inner wall, 23 inner hole, 24 mounting Part, 30A fin, 30B fin, 30a plate member, 31A through hole, 31B through hole, 31R heat transfer tube area, 32R fin area, 40 header, 40-1 cylindrical header, 40-2 laminated header, 40A header, 40A-1 upwind header, 40A-2 downwind header, 40B header, 40B-1 upwind header, 40B-2 downwind header, 40Ba pipe attachment, 40Bb tube attachment, 41 outer wall, 41A upwind heat exchange , 41B Upwind Heat Exchanger, 42A Downwind Heat Exchanger, 42B Downwind Heat Exchanger, 4 Heat transfer tube connection part, 44 internal space, 45A inter-row connection member, 45B inter-row connection member, 46 cylindrical part, 50 preparation process, 51 first process, 52 second process, 60 high pressure gas container, 60a upper stage branch part , 61a connection piping, 62a connection piping, 65 distribution joining channel, 70 sealing device, 71 insertion portion, 72 recess, 80 circular pipe joint, 90 plate-like member, 91 first plate-like member, 91a first plate-like member 91b first plate member 91c first plate member 91d first plate member 91e first plate member 92 second plate member 92a second plate member 92b second plate member 92b 92c second plate-like member, 92 d second plate-like member, 100 refrigeration cycle device, 101 compressor, 102 first heat exchanger, 103 throttling device, 104 second heat exchanger, 10 1st fan, 106 second fan, 107 channel switching device, 110 refrigerant piping, 311 first fin collar, 311a cut, 312 second fin collar, 312a cut, A inner point, B outer end, P1 pitch, P2 pitch, P3 fin pitch, θ angle.

Claims (12)

A plurality of heat transfer tubes which are flat in cross section and in which a plurality of inner holes are formed;
A plurality of fins to which the plurality of heat transfer tubes are joined;
A header connected to the plurality of heat transfer tubes and having a fluid flow passage therein;
The cross-sectional long axis of the heat transfer tube is da, the number of inner holes of the heat transfer tube is n, the thickness of the outer wall of the heat transfer tube is tp, and the required withstand pressure of the heat transfer tube is P.
Assuming that the inner diameter of the header is dh, the thickness of the outer wall of the header is th, and the tensile strength of the header is σ,
The header is
A heat exchanger in which dh / th is configured to 2σ / {P * (da / n / tp-1)} or more. A refrigerant circuit in which a compressor, a first heat exchanger, a throttling device, and a second heat exchanger are connected by a refrigerant pipe,
A refrigeration cycle apparatus using the heat exchanger according to claim 1 as at least one of the first heat exchanger and the second heat exchanger. Forming a plurality of through holes in a plate-like member to be a fin;
A heat transfer pipe is inserted into each of the plurality of through holes,
Sealing one end of the heat transfer tube;
By supplying gas from the other end of the heat transfer tube and expanding the heat transfer tube, the heat transfer tube is joined to the fin,
A method of manufacturing a heat exchanger, comprising bonding the heat transfer tube to the fin and then brazing the heat transfer tube to a header having a fluid flow passage inside. A brazing material is applied or laminated to at least one surface of the heat transfer tube and the fin,
The method for manufacturing a heat exchanger according to claim 3, wherein when the header and the heat transfer pipe are brazed, both the heat transfer pipe and the fin are brazed. Providing a cut in a portion to be a heat transfer tube region of the plate-like member,
Forming the fin collar and the through hole by bending the plate-like member through the cut;
Among the fin collars, the fin collar cut and raised in the longitudinal direction of the fin is a first fin collar,
When the fin collar cut and raised in the short direction of the fin among the fin collars is a second fin collar,
The short side length L1 of the fin of the first fin collar is greater than the longitudinal length L2 of the fin of the second fin collar,
The gap length L3 between the second fin collar and the heat transfer tube inserted into the through hole is greater than the gap length L4 between the first fin collar and the heat transfer tube inserted into the through hole. The manufacturing method of the heat exchanger of Claim 3 or 4 set largely. The heat transfer tube is sealed by inserting one end of the heat transfer tube into a sealing device;
A mounting portion projecting outward is formed on the outer periphery of one end of the heat transfer tube,
The insertion part in which the heat transfer tube of the sealing device is inserted is formed with a recess that is recessed outward.
The heat transfer tube is
The method for manufacturing a heat exchanger according to any one of claims 3 to 5, wherein the mounting portion is fixed to the sealing device by being fitted into the recess. The heat transfer tube is sealed by connecting one end of the heat transfer tube to a sealing device via a joint;
The joint is
The circular tube portion inserted into the insertion portion of the sealing device is fixed to the sealing device by being pressed from the inner wall side and the outer wall side by the insertion portion. The manufacturing method of the described heat exchanger. The heat transfer tube is sealed by inserting one end of the heat transfer tube into a sealing device;
The heat transfer tube is formed with an area having no inner wall forming an inner hole at one end of the heat transfer tube,
The sealing device is formed with an insertion portion into which the heat transfer tube is inserted,
The heat transfer tube is
The heat exchanger according to any one of claims 3 to 5, wherein the region not having the inner wall is fixed to the sealing device by being pressed from the inner wall side and the outer wall side by the insertion portion. Method. The heat transfer tube is
The method for manufacturing a heat exchanger according to any one of claims 3 to 8, wherein a chamfer is formed on the outer wall at one end. The chamfered portion is
The heat exchanger according to claim 9, wherein an angle θ formed by a straight line from the inner point A of the heat transfer tube to the outer end B of the heat transfer tube and the longitudinal direction of the fin is an acute angle. Production method. The heat transfer tube is
The method for manufacturing a heat exchanger according to any one of claims 3 to 10, wherein the cross-sectional shape is flat or circular. The header is
The method for manufacturing a heat exchanger according to any one of claims 3 to 11, which is a hollow header or a laminated header.

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