JP7850984B2 - heat exchanger - Google Patents

Description

This invention relates to a heat exchanger.

Patent Document 1 discloses a heat exchanger capable of suppressing performance degradation. This heat exchanger comprises a first heat transfer tube, a first header section, a second heat transfer tube, a second header section, and a plurality of connecting passages, each having one end connected to the first header section and the other end connected to the second header section, thereby connecting the first and second header sections. The connection position of one end of each connecting passage to the first header section is at the same height relative to all other connecting passages, while the connection position of the other end of each connecting passage to the second header section is at different height relative to all other connecting passages.

Japanese Patent Publication No. 2017-155990

This disclosure provides a heat exchanger that suppresses the uneven distribution of refrigerant to each of the multiple flattened tubes.

This disclosure relates to a heat exchanger comprising a pair of header pipes and a plurality of flat tubes connected to each of the header pipes, wherein when the heat exchanger functions as an evaporator, there is an inlet section through which refrigerant flows from the plurality of flat tubes into the interior of the header pipe, and an outlet section through which refrigerant flows out from the interior of the header pipe into the plurality of flat tubes, the inlet section being located below the outlet section, and the header pipe being provided with a first plate, a second plate, and at least one third plate extending from the inlet section to the outlet section, the first plate being provided with a plurality of inlet holes in the inlet section having the same shape as the cross-section of the flat tube for forming refrigerant inlets from the flat tubes, and the outlet section being provided with a refrigerant inlet for the flat tubes A heat exchanger characterized in that it is provided with a plurality of outlet holes having the same shape as the cross-section of the flattened pipe for forming an outlet, the second plate material is provided with a plurality of rising holes forming a refrigerant rising flow path from the inlet section to the outlet section, the third plate material is provided with a plurality of connecting holes sequentially connecting the inlet hole, the rising holes , and the outlet hole, the plurality of connecting holes provided in the outlet section are provided with at least one branching section that branches the refrigerant in at least two directions, the third plate material is provided with a wall surface facing the flow direction of the refrigerant flowing through the branching section, and the branching section is provided at a height equal to or greater than the height position in the direction of gravity of the plurality of outlet holes connected to the downstream side of the refrigerant flow of the branching section .

According to this disclosure, it is possible to suppress the uneven distribution of refrigerant to each of the multiple flattened tubes.

Perspective view of an outdoor unit according to an embodiment of this disclosure Plan view of the outdoor unit Perspective view of the outdoor heat exchanger A schematic cross-sectional view showing the internal structure of the outdoor heat exchanger. Disassembled perspective view of a shunt. Diagram showing the flow of refrigerant in the splitter of the outdoor heat exchanger. A schematic longitudinal cross-sectional view showing the internal structure of an outdoor heat exchanger according to a modified example of the present disclosure.

(Knowledge and other information that formed the basis of this disclosure)
At the time the inventors conceived of this disclosure, there was a technique for a heat exchanger composed of multiple flat tubes formed by multiple refrigerant flow paths and a pair of header pipes connecting the ends of the flat tubes, wherein a partition plate is provided within the header pipe to divide the multiple flat tubes into multiple heat exchange sections, and connecting pipes are provided to connect the upper part of the lower heat exchange section and the lower and upper parts of the upper heat exchange section, allowing refrigerant to flow in from multiple heights in the heat exchange section. This reduces the effect of gravity when the refrigerant rises and turns within the header pipe, and ensures that the amount of refrigerant flowing through the multiple flat tubes within the header pipe is distributed uniformly.

However, in conventional configurations, each connecting pipe is connected perpendicular to the axial direction of the header pipe. As a result, the gas-liquid two-phase refrigerant flowing through the lower heat exchange section flows in a straight line along the longitudinal direction of the flattened pipes in the upper heat exchange section via the connecting pipes. In particular, liquid refrigerants, which have a high density and are prone to inertial forces, tend to flow easily into heat transfer tubes at a height close to the connecting pipes when they enter the header pipe from the connecting pipes, while flowing less easily into heat transfer tubes located at a height further away from the connecting pipes, resulting in an uneven distribution in the upper heat exchange section. The inventors discovered that this leads to a decrease in heat exchange performance, and in order to solve this problem, they have come to form the subject of this disclosure.
Therefore, this disclosure provides a heat exchanger that suppresses the uneven distribution of refrigerant to each of the multiple flattened tubes.

The embodiments will be described in detail below with reference to the drawings. However, unnecessary details may be omitted. For example, detailed explanations of already well-known matters or redundant explanations of substantially identical configurations may be omitted. This is to avoid the following explanation becoming unnecessarily verbose and to facilitate understanding for those skilled in the art.
The attached drawings and the following description are provided to enable those skilled in the art to fully understand this disclosure and are not intended to limit the subject matter described in the claims.

(Embodiment 1)
Embodiment 1 will be described below with reference to Figures 1 to 6. In each figure, the symbol FR indicates the front of the outdoor unit when it is installed on the mounting surface and in normal use, the symbol UP indicates the area above the outdoor unit, and the symbol LH indicates the area to the left of the outdoor unit. In the following description, each direction is a direction along the direction of these outdoor units.

[1-1. Structure]
[1-1-1. Outdoor Unit Configuration]
Figure 1 is a perspective view of the outdoor unit 1 of the air conditioning system according to this embodiment.
The air conditioning system of this embodiment comprises an indoor heat exchanger housed in an indoor unit and a refrigeration circuit formed by a compressor 5, expansion valve, a pair of outdoor heat exchangers 50, etc., housed in an outdoor unit 1. The air conditioning system provides air conditioning to the space in which the indoor unit is installed by circulating a refrigerant through this refrigeration circuit.

As shown in Figure 1, the outdoor unit 1 of this embodiment is a so-called side-flow type, or horizontal-blowing type, outdoor unit that draws air into the interior through a pair of outdoor heat exchangers 50 arranged on its side, exchanges heat with the refrigerant in this air, and blows it out from the other side.

Figure 2 is a schematic plan view showing the internal structure of the outdoor unit 1. In Figure 2, for the sake of explanation, predetermined locations on the edge of the bottom plate 12 that forms the lower edge of the front air intake 15 and the side air intake 17, and on the back plate 18 that forms the edge of the exhaust port 19 are indicated by dashed lines.
As shown in Figures 1 and 2, the outdoor unit 1 comprises a box-shaped housing 10 whose longitudinal direction extends along the left-right direction. In this embodiment, each part of the housing 10 is formed from steel plate.
The housing 10 comprises a bottom plate 12 that forms the bottom surface of the housing 10, a top plate 14 that forms the top surface, a front plate 16 that forms the front surface, a back plate 18 that forms the rear surface, a left side plate 11 that forms the left side surface, and a right side plate 13 that forms the right side surface.

As shown in Figure 1, the front panel 16 is provided with a front air intake 15. The front air intake 15 is a rectangular opening through which air is drawn from the outside to the inside of the housing 10. On the front panel 16, the front air intake 15 is positioned closer to the left panel 11 than to the right panel 13.
In the front panel 16, multiple fastening holes 20, which are through holes, are provided at positions close to the edge of the right-side panel 13 of the front air intake 15. These fastening holes 20 are arranged to be aligned on the same straight line extending along the vertical direction of the housing 10. In this embodiment, the front panel 16 is provided with three fastening holes 20.

A side air intake 17 is provided on the left side panel 11. The side air intake 17 is a rectangular opening through which air is drawn into the interior of the housing 10. On the left side panel 11, the side air intake 17 is located closer to the front panel 16 than to the rear panel 18.
On the left side panel 11, three fastening holes 20 are provided at positions close to the edge of the side air intake port 17 on the rear panel 18 side, so as to be aligned on the same straight line extending along the vertical direction of the housing 10.

As shown in Figure 2, an exhaust port 19 is provided on the rear panel 18. This exhaust port 19 is an opening through which air drawn into the housing 10 is blown out to the outside of the housing 10.
Furthermore, filters or grid-like protective members may be provided at the front air intake 15, the side air intake 17, and the exhaust port 19.

The internal space S of the housing 10 is divided into two spaces by a partition plate 21. This partition plate 21 is a plate-shaped member that extends along the vertical direction of the housing 10 by a predetermined height dimension, and also extends along the front-to-back direction of the housing 10. The partition plate 21 is fixed to the housing 10 by its lower end being connected to the bottom plate 12. The end of the partition plate 21 located on the front side of the housing 10 is connected to the front plate 16, and the end located on the rear side of the housing 10 is connected to the rear plate 18.
As a result, the housing 10 is divided into two spaces by a partition plate 21: a machine room S1 located on the right side of the housing 10 and a blower room S2 located on the left side of the housing 10.

The machine room S1 houses components that make up the refrigeration circuit, such as the compressor 5, expansion valve, header pipe 52 for the outdoor heat exchanger 50, and refrigerant piping, as well as various electrical components.
The blower room S2 houses the blower fan 30 and the outdoor heat exchanger 50, excluding the header pipe 52.
The blower fan 30 is an axial flow fan that rotates to introduce air from outside the housing 10 into the blower chamber S2, exchanges heat with the refrigerant flowing through the outdoor heat exchanger 50, and then discharges the air back to the outside of the housing 10. This blower fan 30 is equipped with a fan motor 32 and an impeller 34.
The fan motor 32 is a drive unit that rotates the impeller 34, and the fan motor 32 is equipped with a drive shaft 36 to which the impeller 34 is attached.
The impeller 34 is a rotating component that is rotated by the fan motor 32 to send air in the axial direction.
The blower fan 30 is positioned such that the impeller 34 faces the exhaust port 19, and the tip of the drive shaft 36 is positioned toward the exhaust port 19.

[1-1-2. Configuration of the outdoor heat exchanger]
Figure 3 is a perspective view showing the outdoor heat exchanger 50.
The outdoor heat exchanger 50 is a heat exchanger that has a flow path through which the refrigerant flows and functions as an evaporator that evaporates the refrigerant supplied from the indoor unit, or as a condenser that condenses the refrigerant.
As shown in Figures 2 and 3, each of the outdoor heat exchangers 50 in this embodiment is formed in a substantially L-shape when viewed from above. As shown in Figure 2, one outdoor heat exchanger 50 is positioned closer to the blower fan 30 than the other outdoor heat exchanger 50.

Figure 4 is a schematic longitudinal cross-sectional view showing the internal structure of the outdoor heat exchanger 50. For the sake of explanation, in Figure 4, the outdoor heat exchanger 50 is shown as being in a straight line in a plan view.
As shown in Figure 4, the outdoor heat exchanger 50 includes a pair of header pipes 52 and 54, a first refrigerant pipe 66, a second refrigerant pipe 68, a partition wall 60, a plurality of flattened pipes 62, a plurality of fins 64, and a flow divider 80.
In this embodiment, all of these components of the outdoor heat exchanger 50 are made of aluminum or an aluminum alloy.

The header pipes 52 and 54 are both hollow, columnar members extending along the vertical direction of the housing 10. In this embodiment, the header pipes 52 and 54 are both formed in a cylindrical shape. These header pipes 52 and 54 are provided at both ends of the outdoor heat exchanger 50, respectively.

One of the header pipes 52 is connected to the first refrigerant pipe 66 and the second refrigerant pipe 68. The first refrigerant pipe 66 and the second refrigerant pipe 68 function as the inlet or outlet for the refrigerant in the outdoor heat exchanger 50.
The first refrigerant pipe 66 is connected to the upper side 51 of one of the header pipes 52. The second refrigerant pipe 68 is connected to the lower side 51 of one of the header pipes 52.
In this embodiment, the first refrigerant pipe 66 and the second refrigerant pipe 68 are connected to substantially the same location in a plan view in the circumferential direction of the header pipe 52.

As shown in Figure 2, in this embodiment, a connecting pipe 72 is provided, which is a tubular member that connects the second refrigerant pipe 68 of one outdoor heat exchanger 50 to the first refrigerant pipe 66 of the other outdoor heat exchanger 50. This connects one outdoor heat exchanger 50 to the other outdoor heat exchanger 50.

Inside the header pipe 52, a partition wall 60 is provided that vertically separates the internal space SP of the header pipe 52 into an upper space SP1 located above and a lower space SP2 located below. This partition wall 60 is positioned approximately midway between the first refrigerant piping 66 and the second refrigerant piping 68 in the height direction of the header pipe 52.
An internal space SQ is provided inside the header pipe 54.

The multiple flattened tubes 62 are long, flattened tubular members through which a refrigerant flows.
Each flattened pipe 62 is arranged along the longitudinal direction of each header pipe 52, 54, with their respective longitudinal directions parallel to each other, and each end of the flattened pipe 62 is connected to the respective side surfaces 51, 53 of each header pipe 52, 54.
Specifically, one end of each flattened pipe 62 is connected in a line to predetermined locations on the side surface 51 of the header pipe 52, along the longitudinal direction of the header pipe 52, with predetermined intervals between them. Similarly, the other end of each flattened pipe 62 is connected in a line to predetermined locations on the side surface 53 of the header pipe 54, along the longitudinal direction of the header pipe 54, with predetermined intervals between them.
Therefore, the longitudinal direction of each flattened pipe 62 coincides with the longitudinal direction of the outdoor heat exchanger 50.

Each flattened pipe 62 is connected to each header pipe 52, 54 such that their respective width directions are parallel to each other.
Hereinafter, the predetermined locations on the sides 51 and 53 of each header pipe 52 and 54 where each flat pipe 62 is connected are referred to as connection surfaces 55 and 57.

Each flattened pipe 62 has an opening at both ends. One end of each flattened pipe 62 opens to either the upper space SP1 or the lower space SP2, and the other end opens to the internal space SQ.
Hereinafter, the flow path formed by each of the flattened pipes 62 opening into the upper space SP1 will be referred to as the outflow section A1, and the flow path formed by each of the flattened pipes 62 opening into the lower space SP2 will be referred to as the inflow section A2. The inflow section A2 is located below the outflow section A1.
In this embodiment, the outdoor heat exchanger 50 is equipped with nine flattened pipes 62, with six flattened pipes 62 located in the outflow section A1 and three flattened pipes 62 located in the inflow section A2.

Each of the multiple fins 64 is a flat plate member with multiple insertion holes provided on its surface, through which each of the flat pipes 62 can be inserted. Each flat pipe 62 is connected to each header pipe 52, 54 while inserted through each fin 64. That is, each fin 64 is arranged so that its longitudinal and width directions are perpendicular to each flat pipe 62. The longitudinal direction of each fin 64 arranged in this way coincides with the longitudinal direction of each header pipe 52, 54.
In this embodiment, a pair of header pipes 52 and 54, a partition wall 60, a first refrigerant pipe 66, a second refrigerant pipe 68, a plurality of flattened pipes 62, and a plurality of fins 64 are fixed to each other by brazing.

In the fan chamber S2, the outdoor heat exchanger 50 is positioned longitudinally along the front panel 16 and the left panel 11. Specifically, a header pipe 52 is positioned close to the edge of the front air intake 15 on the right panel 13 side, and a header pipe 54 is positioned close to the edge of the side air intake 17 on the rear panel 18 side. The outdoor heat exchanger 50 is then bent and positioned to approach the corner 23 of the housing 10 formed by the front panel 16 and the left panel 11.

The outdoor unit 1 includes fixing members 70 for fixing each of the outdoor heat exchangers 50 to the housing 10.
Specifically, the header pipes 52 of each outdoor heat exchanger 50 are fixed to the front panel 16 by multiple fixing members 70, and the header pipes 54 of each outdoor heat exchanger 50 are fixed to the left panel 11 by multiple fixing members 70. In this embodiment, each header pipe 52, 54 is fixed by three fixing members 70.
In this manner, each header pipe 52, 54 fixed to the housing 10 is positioned with its longitudinal direction aligned with the vertical direction of the housing 10.

As shown in Figure 1, the outdoor heat exchanger 50, arranged in this manner, has most of its flattened pipes 62 and multiple fins 64 exposed from the housing 10 through the front air intake 15 and side air intake 17. Meanwhile, the header pipe 52 is shielded by the front plate 16, and the header pipe 54 is shielded by the left side plate 11.

The partition plate 21 is installed so as to pass between the header pipe 52 and the multiple fins 64. As a result, the header pipe 52 is located in the machine room S1, while the multiple flat pipes 62, fins 64, and header pipe 54 are located in the blower room S2.

[1-1-2. Configuration of the shunt]
Figure 5 is an exploded perspective view of the current shunt 80.
As shown in Figure 4, a flow divider 80 is provided in the internal space SQ of the header pipe 54. As shown in Figure 5, the flow divider 80 is a component formed by combining a first plate material 82, a second plate material 84, and a third plate material 86. The first plate material 82, the second plate material 84, and the third plate material 86 are all plate-shaped members.

The first plate 82, the second plate 84, and the third plate 86 all extend along the entire longitudinal direction of the header pipe 54, with each end contacting the top and bottom surfaces of the header pipe 54. That is, the first plate 82, the second plate 84, and the third plate 86 are all provided to extend across the entire length from the outflow section A1 to the inflow section A2.

The first sheet material 82 corresponds to the "first sheet material" in this disclosure, the second sheet material 84 corresponds to the "second sheet material" in this disclosure, and the third sheet material 86 corresponds to the "third sheet material" in this disclosure.

The first plate material 82 is positioned closest to the connection surface 57. The first plate material 82 is provided with multiple through-holes extending along the thickness direction. Each through-hole is an elongated hole extending in a direction intersecting the longitudinal direction of the first plate material 82. Each through-hole is formed to be substantially the same shape as the opening of each flattened pipe 62 in a plan view of the first plate material 82. Each through-hole is positioned to overlap the other end of each flattened pipe 62 in a plan view of the first plate material 82. One plane of the first plate material 82 is positioned to abut against the other end of each flattened pipe 62. As a result, each through-hole connects to the opening at the other end of each flattened pipe 62.

Hereafter, the through-hole connected to the outflow section A1 will be referred to as the outflow hole 83, and the through-hole connected to the inflow section A2 will be referred to as the inflow hole 81.

The second plate material 84 is positioned so as to abut against the inner surface of the header pipe 54 facing the connecting surface 57. One surface of the second plate material 84 is formed in a curved shape so that its entire surface can abut against the inner surface.
The second plate material 84 is provided with a plurality of through holes, namely a first rising hole 85, a second rising hole 87, and a third rising hole 89, which penetrate along the thickness direction of the plate. The first rising hole 85, the second rising hole 87, and the third rising hole 89 are all elongated holes that extend along the longitudinal direction of the second plate material 84.

The first rising hole 85 is positioned approximately in the center of the second plate material 84 in a direction intersecting the longitudinal direction. In a plan view of the second plate material 84, the lower end of the first rising hole 85 is positioned to overlap with the lowest inlet hole 81. The upper end of the first rising hole 85 is positioned to overlap with the outlet hole 83 located above the lowest outlet hole 83.

The second rising hole 87 is positioned to approach the right side in a direction intersecting the longitudinal direction of the second plate material 84. In a plan view of the second plate material 84, the lower end of the second rising hole 87 is positioned to overlap with the inlet 81 located above the lowest inlet 81. The upper end of the second rising hole 87 extends along the direction intersecting the longitudinal direction of the second plate material 84 to approximately the center in that direction. The upper end of the second rising hole 87 is positioned to overlap with the outlet 83 located above the lowest outlet 83, separated by two outlet 83s.

The third rising hole 89 is positioned close to the left side in a direction intersecting the longitudinal direction of the second plate material 84. In a plan view of the second plate material 84, the lower end of the third rising hole 89 is positioned to coincide with the uppermost inlet hole 81. The upper end of the third rising hole 89 extends along the direction intersecting the longitudinal direction of the second plate material 84 to approximately the center in that direction. The upper end of the third rising hole 89 is positioned to coincide with the uppermost outlet hole 83.

The first rising hole 85, the second rising hole 87, and the third rising hole 89 correspond to the "rising holes" in this disclosure.

The third plate 86 is positioned so as to be sandwiched between the first plate 82 and the second plate 84. This third plate 86 is further formed by combining the wall plate 100, the flow divider plate 102, and the branching plate 104.

The wall panel 100 is positioned close to the first panel 82. One flat surface of the wall panel 100 abuts against the other flat surface of the first panel 82 over its entire surface.
The wall panel 100 is provided with a plurality of through holes that penetrate along the thickness direction. These through holes are positioned to overlap with one end in the longitudinal direction of each of the outflow holes 83 and inflow holes 81 of the first panel 82 when viewed from above. In this embodiment, these through holes are positioned to overlap with the left end of each of the outflow holes 83 and inflow holes 81 of the first panel 82.
Hereinafter, the through-hole overlapping the outflow hole 83 will be referred to as the wall inflow hole 101, and the through-hole overlapping the inflow hole 81 will be referred to as the wall outflow hole 103.

The flow-dividing plate 102 is positioned close to the second plate 84. One plane of the flow-dividing plate 102 abuts against the other plane of the second plate 84.
The lower end of the flow-dividing plate 102 is provided with three through-holes, which are lower inflow communication holes 90 that penetrate along the thickness direction of the plate.
Each of the lower inflow communication holes 90 is positioned to overlap each of the three inflow holes 81.

Three through-holes, or upper outflow communication holes 95, are provided on the upper end side of the diversion plate 102, extending along the plate thickness direction. Each of the upper outflow communication holes 95 is positioned approximately in the center in a direction intersecting the longitudinal direction of the third plate 86.
Each of the upper outflow communication holes 95 is positioned to overlap the upper ends of the first upward hole 85, the second upward hole 87, and the third upward hole 89, respectively.

In a direction intersecting the longitudinal direction of the flow-dividing plate 102, three through-holes, or flow-dividing holes 97, are provided adjacent to each of the upper outflow communication holes 95, extending along the thickness direction of the plate. In this embodiment, in a direction intersecting the longitudinal direction of the flow-dividing plate 102, each of the flow-dividing holes 97 is provided to the right of each of the upper outflow communication holes 95.

Each of the diversion holes 97 is an elongated hole extending along the longitudinal direction of the diversion plate 102. Each of the diversion holes 97 is positioned so that, in a plan view of the diversion plate 102, they do not overlap with each other and do not overlap with the first upward-facing hole 85, the second upward-facing hole 87, and the third upward-facing hole 89.

The branching plate 104 is positioned so as to be sandwiched between the wall plate 100 and the flow-dividing plate 102. One plane of the branching plate 104 abuts against the other plane of the wall plate 100, and the other plane of the branching plate 104 abuts against the other plane of the flow-dividing plate 102.
The flat surface of the wall panel material 100 corresponds to the "wall surface" in this disclosure.

The lower end of the branch plate material 104 is provided with three through-holes, which are lower inflow communication holes 91 that penetrate along the thickness direction of the plate.
Each of the lower inlet communication holes 90 is arranged in a direction that intersects the longitudinal direction of the branch plate material 104, and is positioned to overlap with each of the three inlet holes 81 and each of the lower inlet communication holes 90, starting from the top. Of the three lower inlet communication holes 90, the two located on the lower side are elongated holes that extend along the direction that intersects the longitudinal direction of the branch plate material 104.

Six through-holes are provided on the upper end of the branching plate material 104, extending along the thickness direction. These through-holes are elongated holes, substantially identical in shape to the outflow hole 83 and inflow hole 81, respectively, when viewed from above. When viewed from above, the left end of each of these through-holes is positioned to overlap with the wall inflow hole 101.

Of the six through-holes, the three through-holes located every other from the top are positioned so that, in a plan view of the flow divider plate 102, each overlaps with one of the upper outflow communication holes 95. Each of the upper outflow communication holes 95 is positioned so as to overlap approximately in the center of the longitudinal direction of the through-hole and not overlap with the wall inflow hole 101.
Hereinafter, these three through holes will be referred to as branch holes 110. The branch holes 110 correspond to the "branch section" in this disclosure.

Of the six through-holes, all but the branching hole 110 are positioned so that their rightmost ends overlap with the lower end of the diversion hole 97 and do not overlap with the upper outflow communication hole 95. Hereinafter, these through-holes will be referred to as communication holes 111.

The structure of these first plate material 82, second plate material 84, and third plate material 86 provides the flow divider 80 with three flow paths: a first flow path F1, a second flow path F2, and a third flow path F3.
The first flow path F1 is formed by the lowest inlet 81, the wall outlet 103, the lower inlet communication hole 90, the first rising hole 85, the upper outlet communication hole 95, the lowest branch hole 110, the lowest diversion hole 97, the two lower wall outlet holes 103, and the two lower outlet holes 83.

The second flow path F2 is formed by an inlet 81 located in the center in the vertical direction, a wall outlet 103, a lower inlet communication 90, a second upward opening 87, an upper outlet communication 95, a branching hole 110 located in the center in the vertical direction, a diversion hole 97 located in the center in the vertical direction, two wall outlets 103 located in the center in the vertical direction, and two outlets 83 located in the center in the vertical direction.

The third flow path F3 is formed by the uppermost inlet 81, the wall outlet 103, the lower inlet communication 90, the second upward opening 87, the uppermost outlet communication 95, the uppermost branching opening 110, the uppermost diversion opening 97, the two uppermost wall outlets 103, and the two uppermost outlets 83.

The lower inlet communication hole 90, the lower inlet communication hole 91, the upper outlet communication hole 95, the diversion hole 97, the wall inlet hole 101, the wall outlet hole 103, and the connecting hole 111 correspond to the "communication holes" in this disclosure.

[1-2. Operation]
The operation of the outdoor unit 1, configured as described above, will be explained below.

First, let's explain the flow of refrigerant in an air conditioning system.
In the case of heating operation of the air conditioning system, when the outdoor unit 1 starts operating, the compressor 5 is driven. The compressor 5 compresses the refrigerant sealed in the refrigeration circuit and sends out the gaseous refrigerant through each refrigerant pipe.

This gaseous refrigerant releases heat in the indoor heat exchanger and condenses, then flows through the piping to the expansion valve, where it is depressurized and flows through the second refrigerant piping 68 into the lower space SP2 of one of the outdoor heat exchangers 50. The refrigerant that has flowed into the lower space SP2 flows into the internal space SQ through the flat pipes 62 located below the partition wall 60. After this, the refrigerant flows towards the header pipe 52 through the flat pipes 62 located above the partition wall 60. The refrigerant flowing through the outdoor heat exchanger 50 absorbs heat and evaporates by exchanging heat with the air blown out by the blower fan 30 in the flat pipes 62. After flowing into the upper space SP1, the refrigerant flows into the other outdoor heat exchanger 50 through the first refrigerant piping 66, the connecting pipe 72, and the second refrigerant piping 68. The refrigerant flows through the other outdoor heat exchanger 50 in the same way as in the first outdoor heat exchanger 50, and then returns to the compressor 5 via the first refrigerant piping 66.

When the outdoor unit 1 starts operating, the blower fan 30 begins rotating ahead of the compressor 5. The rotating blower fan 30 draws air from outside the outdoor unit 1 into the interior of the housing 10, i.e., the blower chamber S2. Specifically, the air flows into the blower chamber S2 mainly through the front intake port 15 and the side intake ports 17. The air flowing into the blower chamber S2 passes between each flattened tube 62 and each fin 64 along the direction perpendicular to the longitudinal and vertical directions of the outdoor heat exchanger 50—in other words, along the width direction of the flattened tubes 62.

This promotes heat exchange between the refrigerant flowing inside the multiple flat tubes 62 and the air flowing between the multiple fins 64.
The air that has exchanged heat with the refrigerant is discharged to the outside of the housing 10 through the exhaust port 19 by the blower fan 30.

By repeating the above-described operation, the outdoor unit 1 absorbs heat from the outside air into the refrigeration circuit and sends it into the room.
When the air conditioning system is operating in cooling mode, the refrigerant circulation direction in the refrigeration circuit is reversed compared to heating mode, and the outdoor heat exchanger 50 functions as a condenser.

Figure 6 shows the flow of refrigerant in the flow divider 80 of the outdoor heat exchanger 50.
The refrigerant flowing into the header pipe 54, i.e., the flow divider 80, passes through the flat pipe 62 located in the inflow section A2, at least a portion of which evaporates, resulting in a liquid-gas mixed refrigerant.
As shown in Figure 6, in the flow divider 80, the refrigerant is divided and flows through three channels: the first channel F1, the second channel F2, and the third channel F3.
Specifically, the refrigerant that flows into the header pipe 54 from the lowest inlet 81 flows through the first flow path F1 and is distributed by the branch hole 110 and the diversion hole 97 to the lowest outlet 83 and the outlet 83 located above the said outlet 83, before flowing out into the flat pipe 62.

The refrigerant flowing into the header pipe 54 from the inlet 81 located above the lowest inlet 81 flows through the second flow path F2 and, via the branching hole 110 and the diversion hole 97, is distributed to the outlet 83 located above the two outlet 83s, and to the outlet 83 located below the said outlet 83, before flowing into the flat pipe 62.

The refrigerant flowing into the header pipe 54 from the uppermost inlet 81 flows through the third flow path F3 and, via the branching holes 110 and diversion holes 97, is distributed to the uppermost outlet 83 and another outlet 83 located below it, before flowing into the flat pipe 62.

Thus, in the outdoor heat exchanger 50, the refrigerant flowing in from the flat pipe 62 located in the inflow section A2 flows into three channels: the first channel F1, the second channel F2, and the third channel F3. Without merging, it flows out through each of these channels to the respective flat pipes 62 located in the outflow section A1. This suppresses uneven flow due to density differences within the header pipe 54 of the outdoor heat exchanger 50. Therefore, uneven distribution of the refrigerant to each of the flat pipes 62 located in the outflow section A1 is suppressed, improving the heat exchange performance.

As described above, the outflow section A1 is the section where refrigerant flows out from inside the header pipe 54 into multiple flat pipes 62. The inflow section A2 is the section where refrigerant flows from the multiple flat pipes 62 into the inside of the header pipe 54. In other words, the outflow section A1 is the section where refrigerant flows out from the flow divider 80 into multiple flat pipes 62. The inflow section A2 is the section where refrigerant flows from the multiple flat pipes 62 into the inside of the flow divider 80.

Furthermore, in the flow divider 80, the refrigerant that rises through the first rising hole 85, the second rising hole 87, and the third rising hole 89, and flows into the upper outlet communication hole 95 and the branch hole 110, collides with the plane of the wall panel 100, and branches out in the left-right direction of the wall panel 100. This prevents the refrigerant from traveling in a straight line along the front-rear direction of the flow divider 80 from the first panel 82 towards the second panel 84. Therefore, uneven flow of refrigerant into the outlet hole 83, located directly in front of the upper ends of the first rising hole 85, the second rising hole 87, and the third rising hole 89, is suppressed. As a result, in the outdoor heat exchanger 50, uneven distribution of refrigerant to each of the flat pipes 62 located in the outlet section A1 is suppressed, improving heat exchange performance.

In the flow divider 80, each of the branch holes 110 is located above each of the connecting holes 111 in the three flow paths: the first flow path F1, the second flow path F2, and the third flow path F3.
As a result, the refrigerant, after branching out at each of the branch holes 110, flows into the outlet section A1 without rising against gravity. Therefore, the outdoor heat exchanger 50 can circulate the refrigerant more smoothly.

In the flow divider 80, the height difference between the inlet 81 and the outlet 83, to which each of the first, second, and third flow paths F1, F2, and F3 connects, is suppressed. As a result, the refrigerant flowing through each of the three flow paths (first, second, and third) is affected by gravity in approximately the same way, rising along the vertical direction of the header pipe 54 and being able to flow out through each of the outlet 83. Therefore, in the outdoor heat exchanger 50, the unevenness of the refrigerant flow in the outlet section A1 can be reduced, and the refrigerant can be distributed uniformly through the multiple flat pipes 62.

For example, when an air conditioning system is operated at partial load, resulting in a low refrigerant circulation rate and slow refrigerant flow rate, even during partial load operation of an air conditioning system with particularly low refrigerant circulation rates, the refrigerant can flow to the top of each flow path. This suppresses uneven distribution of the refrigerant to each of the flat pipes 62 located in the outlet section A1, thereby improving heat exchange performance.

In the outdoor heat exchanger 50, when functioning as an evaporator, as heat exchange of the refrigerant progresses, the liquid refrigerant vaporizes into a gaseous refrigerant, making it prone to pressure rise and increasing pressure loss. In this embodiment, more flattened pipes 62 are provided in the outlet section A1 than in the inlet section A2. This allows the refrigerant to flow more smoothly into the outlet section A1 in the outdoor heat exchanger 50, suppressing increased refrigerant pressure loss and improving heat exchange performance.

As described above, in each of the first flow path F1, the second flow path F2, and the third flow path F3, the upper ends of the first rising hole 85, the second rising hole 87, and the third rising hole 89 are positioned to overlap with the upper of the two inlet holes 81 that form each flow path.
As a result, the refrigerant that has risen through the first rising hole 85, the second rising hole 87, and the third rising hole 89 flows in accordance with gravity through each of the diversion holes 97 and is distributed to each of the two inlet holes 81 in each of the respective flow paths. Therefore, the refrigerant that has risen through the first rising hole 85, the second rising hole 87, and the third rising hole 89 is distributed in accordance with gravity through each of the two inlet holes 81 in the first flow path F1, the second flow path F2, and the third flow path F3 without resisting gravity.

[1-3. Effects, etc.]
As described above, in this embodiment, the outdoor heat exchanger 50 comprises a pair of header pipes 52 and 54, and a plurality of flat pipes 62 connected to each of the header pipes 52 and 54. When the outdoor heat exchanger 50 functions as an evaporator, there is an inflow section A2 through which refrigerant flows from the plurality of flat pipes 62 into the header pipe 54, and an outflow section A1 through which refrigerant flows out from the header pipe 54 into the plurality of flat pipes 62. The inflow section A2 is located below the outflow section A1. The header pipe 54 is provided with a first plate material 82, a second plate material 84, and at least one third plate material 86 extending from the inflow section A2 to the outflow section A1.
The first plate material 82 is provided with a plurality of inlet holes 81 in the inlet section A2, which have the same shape as the cross-section of the flat pipe 62, for forming a refrigerant inlet from the flat pipe 62, and a plurality of outlet holes 83 in the outlet section A1, which have the same shape as the cross-section of the flat pipe 62, for forming a refrigerant outlet to the flat pipe 62. The second plate material 84 is provided with a first rise hole 85, a second rise hole 87, and a third rise hole 89, which form a refrigerant rise channel from the inlet section A2 to the outlet section A1.
The third plate material 86 is provided with at least one branch hole 110 in the outflow section A1 that branches the refrigerant in at least two directions, and is provided with a wall surface facing the direction of flow of the refrigerant flowing through the branch hole 110. The branch hole 110 is provided at a height equal to or greater than the height position in the direction of gravity of the plurality of outflow holes 83 connected to the downstream side of the refrigerant flow of the branch hole 110.

As a result, the refrigerant flowing from the multiple flat pipes 62 passes through the inlet hole 81 and, as it flows through the third plate material 86 located in the inlet section A2, it collides with the wall surface and branches in two directions. The refrigerant after branching then flows out into the flat pipes 62 through the multiple outlet holes 83 without rising.

Therefore, the refrigerant flowing from the inlet 81 flows into each channel and, without merging, flows through its respective channel to the outlet section A1, thereby suppressing uneven flow due to density differences within the header pipe 54. Furthermore, in the outdoor heat exchanger 50, uneven distribution to the multiple flattened pipes 62 in the outlet section A1 is suppressed, improving heat exchange performance.

Furthermore, the refrigerant that has risen to the height where the branching hole 110 is located via the first rising hole 85, the second rising hole 87, and the third rising hole 89 can be prevented from flowing further upward after branching. Therefore, when the refrigerant branches, the circulation volume decreases, the flow velocity slows down, making it difficult for it to rise further. This prevents it from flowing to the outlet hole 83 further up after branching, thus preventing uneven flow through the multiple flat pipes 62. In addition, in the outdoor heat exchanger 50, even during partial load operation when the refrigerant circulation volume is low, the refrigerant can be flowed uniformly through the multiple flat pipes 62, improving heat exchange performance.

As in this embodiment, each of the branch holes 110 may be formed extending horizontally from the flow divider 80.

This prevents the refrigerant from branching in the direction of gravity at the branching port 110. Therefore, even during the minimum operation of the air conditioner, when the refrigerant circulation rate is lowest and the flow velocity is particularly slow and the denser liquid refrigerant is less likely to rise, the outdoor heat exchanger 50 can suppress the branching of the denser liquid refrigerant downwards and the less denser gaseous refrigerant upwards. Furthermore, in the outdoor heat exchanger 50, the refrigerant can be uniformly distributed to each of the outlet ports 83 located above and below each flow path, allowing for uniform distribution of the refrigerant through the multiple flattened pipes 62 and improving heat exchange performance.

As in this embodiment, the number of flat pipes 62 present in the outflow section A1 may be greater than the number of flat pipes 62 present in the inflow section A2.
As a result, the refrigerant that has flowed through the outdoor heat exchanger 50 and undergone heat exchange can flow more smoothly to the outlet section A1. Therefore, the heat exchange performance of the outdoor heat exchanger 50 is improved.

(Other embodiments)
As described above, Embodiment 1 has been explained as an example of the technology disclosed in this application. However, the technology in this disclosure is not limited to this and can be applied to embodiments that have been modified, replaced, added, or omitted. Furthermore, it is possible to create new embodiments by combining the components described in Embodiment 1 above.
Therefore, other embodiments are illustrated below.

Figure 7 is a schematic longitudinal cross-sectional view showing the internal structure of an outdoor heat exchanger 150 according to a modified example of the present disclosure.
In Embodiment 1, an outdoor heat exchanger 50 was described in which the refrigerant makes one round trip from header pipe 52 to header pipe 54. However, the invention is not limited to this, and an outdoor heat exchanger 150 in which the refrigerant makes multiple round trips, as shown in Figure 7, may be provided with multiple flow dividers 80. Such an outdoor heat exchanger 150 is provided with multiple outlet sections A1 and multiple inlet sections A2. In this case, it is desirable that the number of multiple flat pipes 62 present in each of the outlet section A1 and inlet section A2 increases as the refrigerant moves downstream in the flow path inside the outdoor heat exchanger 150.

In the above-described embodiment 1, the third plate material 86 is said to include a wall plate material 100, a diversion plate material 102, and a branch plate material 104. However, other plate materials may also be included. In this case, the plate material may be provided with through holes having a similar function to the branch holes 110, or communication holes having substantially the same function as the upper outlet communication holes 95 and diversion holes 97, depending on the number of inlet holes 81 and outlet holes 83.

Furthermore, since the embodiments described above are for illustrative purposes only, various modifications, substitutions, additions, and omissions may be made within the scope of the claims or their equivalents.

This disclosure is applicable to heat exchangers comprising flattened tubes and header pipes. Specifically, this disclosure is applicable to heat exchangers mounted on outdoor units, etc.

1 Outdoor unit 50, 150 Outdoor heat exchanger 52, 54 Header pipe 62 Flat pipe 70 Fixing member 80 Flow divider 81 Inlet hole 82 First plate material (first plate material)
83 Outlet hole 84 Second plate (second plate)
85. First ascending hole (ascending hole)
86. Third board material (third board material)
87. Second ascending hole (ascending hole)
89. Third ascending hole (ascending hole)
90 Lower inflow communication hole (communication hole)
91 Lower inflow communication hole (communication hole)
95 Upper outflow communication hole (communication hole)
97 Diversion hole (communication hole)
100 Wall plate material 101 Wall inflow hole (communication hole)
102 Diversion board material 103 Wall surface outflow hole (communication hole)
104 Branch plate material 110 Branch hole (branch section)
111 Connecting hole (communication hole)
A1 Outflow section A2 Inflow section

Claims (3)

In a heat exchanger comprising a pair of header pipes and a plurality of flattened tubes connected to each of the header pipes,
When the heat exchanger functions as an evaporator, an inflow section is provided through which refrigerant flows from the plurality of flattened tubes into the interior of the header pipe, and an outflow section is provided through which refrigerant flows out from the interior of the header pipe into the plurality of flattened tubes.
The aforementioned inflow section is located below the aforementioned outflow section.
The header pipe is provided with a first plate, a second plate, and at least one third plate, extending from the inlet section to the outlet section.
The first plate material is provided with a plurality of inlet holes in the inlet section having the same shape as the cross-section of the flat pipe for forming a refrigerant inlet from the flat pipe, and a plurality of outlet holes in the outlet section having the same shape as the cross-section of the flat pipe for forming a refrigerant outlet to the flat pipe.
The second plate material is provided with a plurality of rising holes that form a refrigerant rising channel from the inlet section to the outlet section.
The third plate material is provided with a plurality of communication holes that sequentially connect the inlet hole, the rise hole, and the outlet hole.
The plurality of communication holes provided in the outflow section are provided with at least one branching section that branches the refrigerant in at least two directions, and the third plate material is provided with a wall surface facing the flow direction of the refrigerant flowing through the branching section.
The heat exchanger is characterized in that the branch section is provided at a height equal to or greater than the height position in the direction of gravity of the plurality of outlet holes connected to the downstream side of the refrigerant flow of the branch section. The heat exchanger according to claim 1, characterized in that the branching section branches horizontally. The heat exchanger according to claim 1 or 2, characterized in that the number of flattened pipes in the outflow section is greater than the number of flattened pipes in the inflow section.