WO2022244091A1 - Heat exchanger and refrigeration cycle device - Google Patents

Abstract

A heat exchanger according to an embodiment of the present invention has a plurality of heat exchange tubes and headers. The heat exchange tubes are formed with refrigerant channels through which a refrigerant flows. The headers are provided at the ends of the heat exchange tubes. At least one of the headers is formed with a confluence/distribution channel. The confluence/distribution channel merges the refrigerant from two or more of the plurality of heat exchange tubes and distributes the refrigerant to the other two or more heat exchange tubes.

Description

Heat exchanger and refrigeration cycle equipment

Embodiments of the present invention relate to heat exchangers and refrigeration cycle devices.

A header-type heat exchanger has a plurality of heat exchange tubes and a header. The heat exchange tubes have coolant channels. Headers are provided at the ends of the heat exchange tubes. The header has channels through which the coolant flows.
For example, when heat exchange tubes are arranged in a plurality of rows, heat load differences may occur among the plurality of heat exchange tubes. In this case, there is a possibility that the heat exchange efficiency of the heat exchanger may be lowered due to an excessive heat load on some of the heat exchange tubes.

JP-A-8-313115

The problem to be solved by the present invention is to provide a heat exchanger and a refrigeration cycle device that can improve heat exchange efficiency.

The heat exchanger of the embodiment has a plurality of heat exchange tubes and headers. The heat exchange tube is formed with a refrigerant channel through which a refrigerant flows. The headers are provided at the ends of the heat exchange tubes. At least one of the headers is formed with a confluence/distribution channel. The confluence/distribution channel merges the refrigerant from two or more of the plurality of heat exchange tubes and distributes it to the other two or more of the heat exchange tubes.

BRIEF DESCRIPTION OF THE DRAWINGS The schematic block diagram of the refrigerating-cycle apparatus of embodiment. The perspective view of the heat exchanger of 1st Embodiment. 2 is an exploded perspective view of the heat exchanger of the first embodiment; FIG. FIG. 4 is a plan view of an intermediate plate of the first header of the heat exchanger of the first embodiment; The top view of the intermediate plate of the 1st header of the heat exchanger of 2nd Embodiment. The top view of the intermediate plate of the 1st header of the heat exchanger of 3rd Embodiment. The top view of the intermediate plate of the 1st header of the heat exchanger of 4th Embodiment. FIG. 11 is an enlarged plan view of the intermediate plate of the first header of the heat exchanger of the fourth embodiment; The top view of the intermediate plate of the 1st header of the heat exchanger of 5th Embodiment. The top view of the intermediate plate of the 1st header of the heat exchanger of 6th Embodiment. The top view of the intermediate plate of the 1st header of the heat exchanger of 7th Embodiment. The top view of the intermediate plate of the 1st header of the heat exchanger of 8th Embodiment. The top view of the intermediate plate of the 1st header of the heat exchanger of 9th Embodiment. The top view of the intermediate plate of the 1st header of the heat exchanger of a comparative form. FIG. 4 is an enlarged plan view of the intermediate plate of the first header of the heat exchanger of the comparative form;

A heat exchanger and a refrigeration cycle device according to embodiments will be described below with reference to the drawings.

(First embodiment)
FIG. 1 is a schematic configuration diagram of a refrigeration cycle apparatus according to an embodiment.
As shown in FIG. 1, the refrigeration cycle device 1 includes a compressor 2, a four-way valve 3, an outdoor heat exchanger (heat exchanger) 4, an expansion device 5, and an indoor heat exchanger (heat exchanger) 6. And prepare. Components of the refrigeration cycle apparatus 1 are connected by piping 7 . In FIG. 1, the flow direction of the refrigerant (heat medium) during the cooling operation is indicated by solid arrows. The flow direction of the refrigerant during heating operation is indicated by a dashed arrow.

The compressor 2 includes a compressor body 2A and an accumulator 2B. The compressor main body 2A compresses the low-pressure gaseous refrigerant taken thereinto into a high-temperature, high-pressure gaseous refrigerant. The accumulator 2B separates the gas-liquid two-phase refrigerant and supplies the gas refrigerant to the compressor body 2A.

The four-way valve 3 reverses the flow direction of the refrigerant to switch between cooling operation and heating operation. During cooling operation, the refrigerant flows through the compressor 2, the four-way valve 3, the outdoor heat exchanger 4, the expansion device 5, and the indoor heat exchanger 6 in this order. At this time, the outdoor heat exchanger 4 functions as a condenser. The indoor heat exchanger 6 functions as an evaporator.

During heating operation, the refrigerant flows through the compressor 2, the four-way valve 3, the indoor heat exchanger 6, the expansion device 5, and the outdoor heat exchanger 4 in this order. At this time, the indoor heat exchanger 6 functions as a condenser. The outdoor heat exchanger 4 functions as an evaporator.

The condenser converts the high-temperature, high-pressure gaseous refrigerant discharged from the compressor 2 into a high-pressure liquid refrigerant by radiating heat to the outside air and condensing it. The expansion device 5 reduces the pressure of the high-pressure liquid refrigerant sent from the condenser to convert it into a low-temperature, low-pressure gas-liquid two-phase refrigerant. The evaporator absorbs heat from the outside air and evaporates the low-temperature, low-pressure gas-liquid two-phase refrigerant sent from the expansion device 5, thereby converting it into a low-pressure gaseous refrigerant.

In the refrigeration cycle device 1, the refrigerant, which is the working fluid, circulates while changing its phase between gas refrigerant and liquid refrigerant. The refrigerant releases heat during the phase change from gas refrigerant to liquid refrigerant. The refrigerant absorbs heat during the phase change from the liquid refrigerant to the gas refrigerant. The refrigerating cycle device 1 performs heating, cooling, defrosting, etc. by utilizing the heat radiation or heat absorption of the refrigerant.

FIG. 2 is a perspective view of the heat exchanger of the first embodiment. As shown in FIG. 2, this heat exchanger is used as one or both of the outdoor heat exchanger 4 and the indoor heat exchanger 6 (see FIG. 1) of the refrigeration cycle apparatus 1. Hereinafter, a case where the heat exchanger of the embodiment is used as the outdoor heat exchanger 4 (see FIG. 1) of the refrigeration cycle device 1 will be described as an example.

The positional relationship of the heat exchanger 4 is provisionally defined in line with FIGS. The X, Y and Z directions are defined as follows. The Z direction is the longitudinal direction (extending direction) of the first header and the second header. For example, the Z direction is the vertical direction. The +Z direction is the upward direction (height direction). The X direction is the central axis direction (extending direction) of the heat exchange tubes. For example, the X direction is horizontal. The +X direction is the direction from the second header to the first header. The Y direction is the direction perpendicular to the X and Z directions. The Y direction is horizontal. A YZ plane is a plane formed by the Y direction and the Z direction.

The heat exchanger 4 has a first header 10 , a second header 20 and a plurality of heat exchange tubes (heat transfer tubes) 30 .
The first header 10 is connected to the +X direction end of the heat exchange tube 30 . The second header 20 is connected to the end of the heat exchange tube 30 in the -X direction.

The first header 10 and the second header 20 are formed in a flat plate shape parallel to the YZ plane. In this embodiment, the first header 10 and the second header 20 are rectangular when viewed from the X direction. The shape of the first header 10 and the second header 20 is a rectangular shape whose longitudinal direction is along the Z direction. The first header 10 and the second header 20 are made of a material with high thermal conductivity and low specific gravity. Metals such as aluminum and aluminum alloys are examples of "materials with high thermal conductivity and low specific gravity".

FIG. 3 is an exploded perspective view of the heat exchanger of the first embodiment. As shown in FIG. 3 , the first header 10 includes an inner end plate (second end plate) 11 , an intermediate plate 14 and an outer end plate (first end plate) 17 . The inner end plate 11 is superimposed on the surface of the intermediate plate 14 on the −X direction side. The outer end plate 17 overlaps the surface of the intermediate plate 14 on the +X direction side.

4 is a plan view of the intermediate plate 14. FIG. As shown in FIG. 4, the intermediate plate 14 has a plurality of spatial channels 16 (16A, 16B, 16G, 16H) and a spatial channel . The spatial channels 16 and 116 serve as coolant channels. The spatial flow paths 16 and 116 are formed by through-holes passing through the intermediate plate 14 in the thickness direction. The openings of the spatial channels 16, 116 are closed by the inner end plate 11 and the outer end plate 17 (see FIG. 3). Spatial channel 116 is an example of a confluence/distribution channel.

The plurality of spatial channels 16 include a first spatial channel 16A, a second spatial channel 16B, a third spatial channel 16G and a fourth spatial channel 16H. The spatial flow path 16 has an oval shape when viewed from the X direction. "Oval shape" is a shape composed of two straight lines parallel to each other and two curved lines. A curve is a curved convex shape (eg, semicircular, elliptical arc, etc.) that connects the ends of two straight lines, respectively. The longitudinal direction of the spatial flow channel 16 is parallel to the Y direction. The plurality of spatial channels 16 are formed apart from each other. The plurality of spatial channels 16 have the same shape.

The first spatial flow channel 16A and the second spatial flow channel 16B are formed side by side in the Y direction with an interval in the Y direction. The second spatial flow channel 16B is located on the +Y direction side with respect to the first spatial flow channel 16A.

The spatial channel 116 is positioned lower than the first spatial channel 16A and the second spatial channel 16B. The spatial flow channel 116 is located away from the first spatial flow channel 16A and the second spatial flow channel 16B in the -Z direction. The spatial flow channel 116 has an oval shape when viewed from the X direction. The longitudinal direction of the spatial flow channel 116 is parallel to the Y direction. The long diameter of the spatial flow channel 116 is larger than the long diameter of the spatial flow channel 16 .

The third spatial flow channel 16G and the fourth spatial flow channel 16H are positioned lower than the spatial flow channel 116. The third spatial flow channel 16G and the fourth spatial flow channel 16H are positioned away from the spatial flow channel 116 in the -Z direction. The third spatial flow channel 16G and the fourth spatial flow channel 16H are formed side by side in the Y direction with an interval in the Y direction. The fourth spatial flow channel 16H is located on the +Y direction side with respect to the third spatial flow channel 16G.

In the inner end plate 11, one through hole 41 is formed at each position corresponding to the spatial flow path 16 (16A, 16B, 16G, 16H). The through hole 41 is slit-shaped along the Y direction. The +X direction end of the heat exchange tube 30 is inserted into the through hole 41 . The +X direction end of the heat exchange tube 30 opens into the spatial flow path 16 . Therefore, each spatial channel 16 communicates with the refrigerant channel 34 of one heat exchange tube 30 .

The through holes 41 formed in the inner end plate 11 at positions corresponding to the spatial flow paths 16A, 16B, 16G and 16H are called through holes 41A, 41B, 41G and 41H, respectively.

Four through holes 41 are formed in the inner end plate 11 at positions corresponding to the spatial flow paths 116 . The +X direction end of the heat exchange tube 30 is inserted into the through hole 41 . The +X direction end of the heat exchange tube 30 opens into the spatial flow path 116 . Therefore, the spatial channel 116 communicates with the refrigerant channels 34 of the four heat exchange tubes 30 .

The four through-holes 41 formed in the spatial flow path 116 are through- holes 41C, 41D, 41E, and 41F, respectively. The through holes 41C and 41D are formed side by side in the Y direction with a space therebetween. The through hole 41D is located on the +Y direction side with respect to the through hole 41C. The through holes 41E and 41F are located away from the through holes 41C and 41D in the -Z direction. The through- holes 41E and 41F are formed side by side in the Y-direction with an interval in the Y-direction. The through hole 41F is positioned on the +Y direction side with respect to the through hole 41E.

The through holes 41A, 41C, 41E, and 41G are arranged in this order at intervals in the Z direction. The through holes 41B, 41D, 41F, and 41H are arranged in this order at intervals in the Z direction. The heat exchange tubes 30 inserted into the through holes 41A-41H are referred to as heat exchange tubes 30A-30H, respectively.

As shown in FIG. 3, two through holes 42 are formed in the outer end plate 17 . Tubular first refrigerant ports 51 are inserted into the through-holes 42 (see FIG. 2). One end of the first coolant port 51 opens to the third spatial flow channel 16G. The other end of the first coolant port 51 opens into the fourth spatial flow channel 16H. These openings serve as inlets for introducing the refrigerant into the heat exchanger 4 or outlets for leading the refrigerant out of the heat exchanger 4 .

Two through holes 43 are formed in the outer end plate 17 . Tubular second refrigerant ports 52 are inserted into the through-holes 43 (see FIG. 2). One end of the second coolant port 52 opens into the first spatial flow channel 16A. The other end of the second coolant port 52 opens into the second spatial flow channel 16B. These openings serve as inlets for introducing the refrigerant into the heat exchanger 4 or outlets for leading the refrigerant out of the heat exchanger 4 .

The second header 20 has a pair of small headers 20A and 20B. The small headers 20A and 20B are arranged side by side in the Y direction. Each of the small headers 20A, 20B has an inner end plate 21, an intermediate plate 24, and an outer end plate 27. The inner end plate 21 overlaps the surface of the intermediate plate 24 on the +X direction side. The outer end plate 27 is superimposed on the surface of the intermediate plate 24 on the -X direction side.

The intermediate plate 24 has a plurality of spatial channels (not shown). These spatial channels serve as coolant channels. These spatial flow paths are formed by through holes penetrating through the intermediate plate 24 in the thickness direction. The openings of these spatial channels are closed by the inner end plate 21 and the outer end plate 27 .

The heat exchange tube 30 is formed in a flat tubular shape. That is, the heat exchange tube 30 has a larger dimension in the Y direction than the dimension in the Z direction. The shape of the cross section (YZ cross section) perpendicular to the length direction of the heat exchange tube 30 is an elliptical shape. The heat exchange tubes 30 extend in the X direction. A refrigerant channel 34 is formed inside the heat exchange tube 30 . The heat exchange tube 30 is made of a material with high thermal conductivity and low specific gravity. Metals such as aluminum and aluminum alloys are examples of "materials with high thermal conductivity and low specific gravity".

At least some of the plurality of heat exchange tubes 30 are arranged in parallel at intervals in the Z direction. Specifically, the four heat exchange tubes 30 (30A, 30C, 30E, 30G) connected to the through holes 41A, 41C, 41E, 41G of the first header 10 are arranged side by side at intervals in the Z direction. there is That is, the four heat exchange tubes 30 (30A, 30C, 30E, 30G) are arranged in multiple stages (four stages). The four heat exchange tubes 30 (30B, 30D, 30F, 30H) connected to the through holes 41B, 41D, 41F, 41H of the first header 10 are arranged side by side at intervals in the Z direction. That is, the four heat exchange tubes 30 (30B, 30D, 30F, 30H) are arranged in multiple stages (four stages).

The eight heat exchange tubes 30 are arranged in two rows. The eight heat exchange tubes 30 are arranged in a 2×4 matrix when viewed from the X direction. The heat exchange tubes 30A, 30C, 30E, and 30G are referred to as the heat exchange tubes 30 of the first row. The heat exchange tubes 30B, 30D, 30F, and 30H are called the heat exchange tubes 30 of the second row.
Note that the number of rows formed by the plurality of heat exchange tubes 30 is not limited to two. The number of rows formed by the plurality of heat exchange tubes 30 may be plural (any number equal to or greater than 2).

The -X direction end of the heat exchange tube 30 is inserted into the through hole 45 formed in the second header 20 . As a result, the −X direction end of the refrigerant channel 34 of the heat exchange tube 30 opens into the spatial channel of the second header 20 . Therefore, the spatial flow paths of the second header 20 communicate with the refrigerant flow paths 34 of the heat exchange tubes 30 .

The gap between the first header 10 and the heat exchange tube 30 and the gap between the second header 20 and the heat exchange tube 30 are sealed by brazing or the like.

Between the vertically adjacent heat exchange tubes 30, outside air flow paths are formed along the Y direction. The heat exchanger 4 circulates outside air through an outside air flow path using a fan (not shown) or the like. The heat exchanger 4 exchanges heat between the outside air flowing through the outside air passage and the refrigerant flowing through the refrigerant passage 34 . Heat exchange is performed indirectly through the heat exchange tubes 30 .

When the refrigeration cycle device 1 shown in FIG. 1 performs heating operation, the heat exchanger 4 functions as an evaporator. In this case, the heat exchanger 4 converts the low-temperature, low-pressure gas-liquid two-phase refrigerant sent from the expansion device 5 into a low-pressure gaseous refrigerant by absorbing heat from the outside air and vaporizing it.

As shown in FIG. 4, for example, the coolant flows from the two first coolant ports 51 (see FIG. 2) into the third spatial flow channel 16G and the fourth spatial flow channel 16H of the first header 10, respectively. As shown in FIG. 3, the refrigerant flows through the heat exchange tubes 30G and 30H in the −X direction and into different spatial flow paths of the second header 20, respectively. The refrigerant flows through the heat exchange tubes 30</b>E and 30</b>F in the +X direction, and flows into the spatial flow paths 116 of the first header 10 .

As shown in FIG. 4, the refrigerant that has flowed in from the heat exchange tubes 30E and the refrigerant that has flowed in from the heat exchange tubes 30F join in the spatial flow path 116. As shown in FIG. Refrigerant in the spatial flow channel 116 is distributed to the heat exchange tubes 30C and the heat exchange tubes 30D.

As shown in FIG. 3, the refrigerant distributed to the heat exchange tubes 30C and 30D flows through the heat exchange tubes 30C and 30D in the -X direction and flows into different spatial channels of the second header 20, respectively. The refrigerant flows in the +X direction through the plurality of heat exchange tubes 30A and 30B, and flows into the first spatial flow channel 16A and the second spatial flow channel 16B of the first header 10, respectively. The refrigerant flows out of the system from the second refrigerant port 52 (see FIG. 2).

In this example, refrigerant is introduced from the first refrigerant port 51 (see FIG. 2), passes through the heat exchange tubes 30, travels between the first header 10 and the second header 20, and flows through the second refrigerant port 52 (see FIG. 2). 2).

In the heat exchanger 4 , the first header 10 has a spatial channel (joint/distribution channel) 116 . The spatial flow path 116 joins the refrigerant from the two heat exchange tubes 30 (30E, 30F) and distributes it to the other two heat exchange tubes 30 (30C, 30D). In the heat exchanger 4 , the refrigerant flowing through the first row of heat exchange tubes 30 and the refrigerant flowing through the second row of heat exchange tubes 30 can be mixed and redistributed within the spatial flow channels 116 .

There may be a difference in heat load between the heat exchange tubes 30 in the first row and the heat exchange tubes 30 in the second row. The difference in heat load can be reduced. Therefore, it is possible to prevent the heat exchange efficiency from being lowered due to the difference in heat load. Therefore, the heat exchange efficiency in the heat exchanger 4 can be improved.

For comparison, assume a heat exchanger in which the first header is provided with an external pipeline (joint branch pipeline) for mixing and redistributing the refrigerant. A heat exchanger with this structure is inferior in storability because the external pipe line protrudes from the first header. In contrast, in the heat exchanger 4 of the embodiment, since the refrigerant is mixed and redistributed within the first header 10, no external pipe line is required. Therefore, the heat exchanger 4 shown in FIG. 2 can be made compact and is excellent in storability. The heat exchanger 4 also has the advantage of being lightweight due to the lack of external lines.

In this embodiment, the refrigerants from two heat exchange tubes are merged and distributed to the other two heat exchange tubes, but the number of refrigerants to be merged is not limited to two, and may be plural (any number equal to or greater than two). It's okay. The number of heat exchange tubes for distributing the refrigerant is not limited to two, and may be plural (any number equal to or greater than two). That is, the confluence distribution channel merges the refrigerant supplied from two or more of the plurality of heat exchange tubes and distributes it to the other two or more heat exchange tubes.
The number of confluence/distribution channels formed in the first header is not limited to one, and may be plural (any number equal to or greater than two). The confluence/distribution channel may be formed in the intermediate plate of the second header. The number of confluence/distribution channels formed in the second header may be one or more (any number equal to or greater than two). The confluence/distribution channel is formed in at least one of the first header and the second header. The confluence/distribution channel may be formed in one of the first header and the second header, or may be formed in both.

(Second embodiment)
FIG. 5 is a plan view of the intermediate plate 214 of the first header 210 of the heat exchanger of the second embodiment. Configurations common to other embodiments are denoted by the same reference numerals, and descriptions thereof are omitted.

As shown in FIG. 5, the intermediate plate 214 has spatial channels 16 and spatial channels 216 . The heat exchanger of the second embodiment has the same configuration as the heat exchanger of the first embodiment shown in FIG. Spatial channel 216 is an example of a confluence/distribution channel.

The spatial flow path 216 has an oval shape when viewed from the X direction. The longitudinal direction of the spatial flow channel 216 is parallel to the Y direction. Protrusions 217 are formed at both ends of the spatial flow channel 216 . The pair of protruding portions 217 protrude toward each other along the Y direction. The projecting portion 217 is formed substantially in the center of the spatial flow channel 216 in the height direction. The projecting portion 217 has a U-shape formed by combining a pair of straight portions and a curved portion. The pair of linear portions are parallel and face each other. The curved portion has a curved convex shape (for example, a semicircular shape). A narrow portion 218 is provided between the tip of one protrusion 217 and the tip of the other protrusion 217 . In the narrowed portion 218, the passage of the coolant is narrowed.

The narrowed portion 218 preferably satisfies the following equation.
D1>2300μA1/W1
(D1 is the hydraulic equivalent diameter [m] of the narrow portion 218. μ is the viscosity of the refrigerant [Pa s]. A1 is the cross-sectional area [m ² ] of the narrowest portion of the narrow portion 218. W1 is the mass flow rate [kg/s] of the refrigerant flowing through the narrow portion 218.)
The cross-sectional area of the narrow portion 218 is the area of the flow path in the cross section perpendicular to the flow direction of the coolant in the narrow portion 218 . The flow direction of the coolant in the narrow portion 218 is the +Z direction. A cross section perpendicular to the flow direction of the coolant in the narrow portion 218 is along the horizontal plane.

When the narrowed portion 218 satisfies this formula, the refrigerant flowing through the narrowed portion 218 tends to become turbulent, so that the non-uniform flow of the gas-liquid two-phase refrigerant in the space flow path 216 can be suppressed.

The refrigerant that has flowed in from the heat exchange tubes 30E and the refrigerant that has flowed in from the heat exchange tubes 30F join in the spatial flow path 216. As shown by the arrow in FIG. 5, the refrigerant rises in the narrow portion 218 in the +Z direction (opposite to the direction of gravity), collides with the upper surface of the spatial flow path 216, and splits into left and right, and heat-exchanges with the heat exchange tube 30C. and tube 30D.

In this heat exchanger, since the first header 210 has the spatial flow paths 216 , the refrigerant flowing through the heat exchange tubes 30 in the first row and the refrigerant flowing through the heat exchange tubes 30 in the second row flow through the spatial flow paths 216 . can be mixed and redistributed within Therefore, the heat exchange efficiency in the heat exchanger can be enhanced.

In this heat exchanger, a narrowed portion 218 is formed in the space channel 216 . Refrigerants tend to become turbulent because they are diffused when they are released after being collected once by passing through a narrow portion. Therefore, the drift of the gas-liquid two-phase refrigerant in the space channel 216 can be suppressed.

(Third Embodiment)
FIG. 6 is a plan view of the intermediate plate 314 of the first header 310 of the heat exchanger of the third embodiment. Configurations common to other embodiments are denoted by the same reference numerals, and descriptions thereof are omitted.
As shown in FIG. 6, intermediate plate 314 has spatial channels 16 and spatial channels 316 . Spatial flow channel 316 is an example of a confluence/distribution flow channel.

The spatial flow path 316 has an oval shape. The spatial flow channel 316 has a pair of straight portions 316a and a pair of curved portions 316b. The pair of linear portions 316a are parallel and face each other. One curved portion 316b connects one ends of the two straight portions 316a. The other curved portion 316b connects the other ends of the two straight portions 316a. The curved portion 316b has a curved convex shape (for example, a semicircular shape). The longitudinal direction of the spatial channel 316 is inclined with respect to the Y direction. In the spatial flow channel 316, the curved portion 316b on the upstream side of the outside air flow in the above-described outside air flow channel (the outside air flow channel formed between the adjacent heat exchange tubes 30) is larger than the curved portion 316b on the downstream side. incline so that it is positioned higher than the

A protruding portion 317 is formed on each of the pair of linear portions 316a. The pair of protruding portions 317 protrude toward each other along the minor axis direction of the spatial flow channel 316 . The projecting portion 317 is formed substantially in the center in the length direction of the straight portion 316a. The projecting portion 317 has a U-shape combining a pair of straight portions and a curved portion. The pair of linear portions are parallel and face each other. The curved portion has a curved convex shape (for example, a semicircular shape). A narrow portion 318 is provided between the tip of one protrusion 317 and the tip of the other protrusion 317 .

The narrowed portion 318 preferably satisfies the following equation.
D2>2300μA2/W2
(D2 is the hydraulic equivalent diameter [m] of the narrow portion 318. μ is the viscosity of the refrigerant [Pa s]. A2 is the cross-sectional area [m ² ] of the narrowest portion of the narrow portion 318. W2 is the mass flow rate [kg/s] of the refrigerant flowing through the narrow portion 218.)
The cross-sectional area of the narrow portion 318 is the area of the flow path in the cross section perpendicular to the flow direction of the coolant in the narrow portion 318 .
When the narrowed portion 318 satisfies this formula, the refrigerant flowing through the narrowed portion 318 tends to be turbulent, so that the flow deviation of the gas-liquid two-phase refrigerant in the space flow path 316 can be suppressed.

The coolant flows from the first coolant port into the second spatial flow channel 16B and the fourth spatial flow channel 16H of the first header 10, respectively. The refrigerants flow through the heat exchange tubes 30B and 30H in the −X direction, respectively, and flow into different spatial flow paths of the second header 20, respectively. The refrigerant flows through the heat exchange tubes 30D and 30F in the +X direction, and flows into the spatial flow paths 316 of the first header 10. As shown in FIG.

The refrigerant that has flowed in from the heat exchange tubes 30D and the refrigerant that has flowed in from the heat exchange tubes 30F join in the spatial flow path 316. As indicated by the arrow in FIG. 6, the refrigerant flows obliquely downward, passes through the narrowed portion 318, collides with the inner surface of the curved portion 316b, and is divided into upper and lower portions, and is distributed to the heat exchange tubes 30C and 30E. . Since the refrigerant passing through the narrow portion 318 flows obliquely downward, the flow velocity tends to be higher due to the influence of gravity than when the refrigerant flows upward (see FIG. 5).

The refrigerant distributed to the heat exchange tubes 30C, 30E flows through the heat exchange tubes 30C, 30E in the -X direction, and flows into different spatial channels of the second header 20, respectively. The refrigerant flows through the plurality of heat exchange tubes 30A and 30G in the +X direction, and flows into the first spatial flow channel 16A and the third spatial flow channel 16G of the first header 10, respectively. Coolant flows out of the second coolant port.

In this heat exchanger, since the first header 310 has the spatial flow paths 316 , the refrigerant flowing through the heat exchange tubes 30 in the first row and the refrigerant flowing through the heat exchange tubes 30 in the second row flow through the spatial flow paths 316 . can be mixed and redistributed within Therefore, the heat exchange efficiency in the heat exchanger can be enhanced.

In this heat exchanger, a narrowed portion 318 is formed in the spatial flow channel 316, and the spatial flow channel 316 is inclined. Therefore, the refrigerant passes through the narrow portion 318 with momentum due to the influence of gravity. In this heat exchanger, since the refrigerant is passed through a narrow portion with force, the refrigerant is once concentrated and then released to diffuse. Therefore, the refrigerant tends to become turbulent. Therefore, it is possible to suppress drift in the gas-liquid two-phase refrigerant in the space channel 316 .

Although the spatial flow channel 316 is formed to be inclined in this embodiment, the spatial flow channel 316 may have its major axis direction parallel to the Y direction.

(Fourth embodiment)
FIG. 7 is a plan view of the intermediate plate 414 of the first header 410 of the heat exchanger of the fourth embodiment. FIG. 8 is an enlarged plan view of intermediate plate 414 . Configurations common to other embodiments are denoted by the same reference numerals, and descriptions thereof are omitted.

As shown in FIG. 7, the intermediate plate 414 has a plurality of spatial channels 16 (16A to 16H) and the confluence/distribution channels 12. The spatial flow path 16 is formed by a through hole penetrating through the intermediate plate 414 in the thickness direction. The plurality of spatial channels 16 include first spatial channels 16A to eighth spatial channels 16H. The spatial flow channels 16 (16A to 16H) have an oval shape when viewed from the X direction. The longitudinal direction of the spatial flow channel 16 is parallel to the Y direction. The plurality of spatial channels 16 are formed apart from each other. The plurality of spatial channels 16 have the same shape.

The first spatial flow channel 16A and the second spatial flow channel 16B are formed side by side in the Y direction with an interval in the Y direction. The second spatial flow channel 16B is located on the +Y direction side with respect to the first spatial flow channel 16A.

The third spatial flow channel 16C and the fourth spatial flow channel 16D are positioned lower than the first spatial flow channel 16A and the second spatial flow channel 16B, respectively. The third spatial flow channel 16C and the fourth spatial flow channel 16D are located away from the first spatial flow channel 16A and the second spatial flow channel 16B in the -Z direction. The third spatial flow channel 16C and the fourth spatial flow channel 16D are formed side by side in the Y direction with an interval in the Y direction. The fourth spatial flow channel 16D is located on the +Y direction side with respect to the third spatial flow channel 16C.

The fifth spatial flow channel 16E and the sixth spatial flow channel 16F are positioned lower than the third spatial flow channel 16C and the fourth spatial flow channel 16D, respectively. The fifth spatial flow channel 16E and the sixth spatial flow channel 16F are located away from the third spatial flow channel 16C and the fourth spatial flow channel 16D in the -Z direction. The fifth spatial flow channel 16E and the sixth spatial flow channel 16F are formed side by side in the Y direction with an interval in the Y direction. The sixth spatial flow channel 16F is located on the +Y direction side with respect to the fifth spatial flow channel 16E.

The seventh spatial flow channel 16G and the eighth spatial flow channel 16H are positioned lower than the fifth spatial flow channel 16E and the sixth spatial flow channel 16F, respectively. The seventh spatial flow channel 16G and the eighth spatial flow channel 16H are located away from the fifth spatial flow channel 16E and the sixth spatial flow channel 16F in the -Z direction. The seventh spatial flow channel 16G and the eighth spatial flow channel 16H are formed side by side in the Y direction with an interval in the Y direction. The eighth spatial flow channel 16H is positioned on the +Y direction side with respect to the seventh spatial flow channel 16G.

The spatial flow channels 16A, 16C, 16E, and 16G are arranged side by side in the Z direction. The spatial flow channels 16B, 16D, 16F, and 16H are arranged side by side in the Z direction. The eight spatial channels 16 are arranged in two rows. The eight spatial channels 16 are arranged in a 2×4 matrix. The spatial channels 16A, 16C, 16E, and 16G are referred to as the spatial channels 16 of the first row. The spatial channels 16B, 16D, 16F, and 16H are referred to as the spatial channels 16 of the second row.
The pitch P1 is the height difference between the central axes of the vertically adjacent heat exchange tubes 30 .
Note that the number of rows formed by the plurality of spatial flow channels 16 is not limited to two. The number of rows formed by the plurality of spatial flow channels 16 may be plural (any number equal to or greater than 2).

The confluence/distribution channel 12 is formed by a through-hole that penetrates the intermediate plate 414 in the thickness direction. The confluence distribution channel 12 distributes the coolant from the seventh spatial channel 16G and the eighth spatial channel 16H to the fifth spatial channel 16E and the sixth spatial channel 16F.

The confluence/distribution channel 12 has a plurality of lead-out channels 61 , one confluence channel 62 , and a plurality of branch channels 63 . The number of lead-out channels 61 is two. The number of branch flow paths 63 is two. Note that the number of lead-out channels and branch channels is not limited to two, and may be any number equal to or greater than two.

A portion including the base ends of the branch flow paths 63A and 63B is the direction changing portion 615. The direction changing portion 615 is a curved channel including the base ends of the branch channels 63A and 63B. The direction changing part 615 changes the flow direction of the coolant from the confluence channel 62 .

The two outlet channels 61 are called a first outlet channel 61A and a second outlet channel 61B, respectively. The first lead-out channel 61A extends in the +Y direction with the +Y direction end of the seventh spatial channel 16G as its base end. The first outlet channel 61A guides the coolant from the seventh spatial channel 16G. The second lead-out channel 61B extends in the -Y direction with the -Y direction end of the eighth spatial channel 16H as its base end. The second outlet channel 61B guides the coolant from the eighth spatial channel 16H. The first outlet channel 61A and the second outlet channel 61B are formed at the same height position. The first outlet channel 61A and the second outlet channel 61B are connected at the tip.

The confluence channel 62 extends straight in the +Z direction, which is the direction opposite to the direction of gravity, with the connecting point between the tips of the first outlet channel 61A and the second outlet channel 61B as the base end. The confluence channel 62 is a channel along the vertical direction. The confluence channel 62 is located closer to the +Y direction than the spatial channels 16 (16A, 16C, 16E, 16G) in the first row. The confluence channel 62 is located closer to the -Y direction than the second row of spatial channels 16 (16B, 16D, 16F, 16H). The confluence channel 62 joins the refrigerant from two or more spatial channels 16 out of the plurality of spatial channels 16 .

In FIG. 7, the confluence channel 62 is formed from both the first row of spatial channels 16 (16A, 16C, 16E, 16G) and the second row of spatial channels 16 (16B, 16D, 16F, 16H). It is formed at an intermediate position separated by the same distance. The length L1 of the confluence channel 62 is greater than the vertical pitch P1 of the heat exchange tubes 30 . Since the length L1 is greater than the pitch P1, the confluence channel 62 has a sufficient length. Therefore, the gas-liquid two-phase refrigerant can be sufficiently mixed in the confluence passage 62, and the drift of the refrigerant can be suppressed. Therefore, the unevenness in the amount of refrigerant flowing into the plurality of branched flow paths 63 can be reduced.

Since the length L1 of the confluence channel 62 is greater than the pitch P1 of the heat exchange tubes 30, the +Z direction end (tip) of the confluence channel 62 is higher than the heat exchange tubes 30 connected to the spatial flow channels 16E and 16F. in position. The +Z-direction end (tip) of the confluence channel 62 is desirably positioned higher than the spatial channels 16E and 16F.

The branch channel 63 distributes the refrigerant from the confluence channel 62 to the other two or more spatial channels 16 (two or more of the spatial channels 16 other than the spatial channels 16G and 16H). The two branched flow paths 63 are referred to as a first branched flow path 63A and a second branched flow path 63B, respectively. The first branched flow path 63A and the second branched flow path 63B are flow paths formed by branching the confluence flow path 62 into two.

The first branch flow path 63A is a linear flow path that extends obliquely downward with the end (tip) of the confluence flow path 62 in the +Z direction as the base end. The first branch flow path 63A is inclined downward toward the -Y direction. The first branch channel 63A reaches the fifth spatial channel 16E. The first branch channel 63A can guide the coolant to the fifth spatial channel 16E. The fifth spatial channel 16E is the spatial channel 16 of the distribution destination.

The second branch flow path 63B is a linear flow path extending obliquely downward from the +Z direction end (tip) of the confluence flow path 62 as a base end. The second branch channel 63B is inclined so as to descend in the +Y direction. The second branch channel 63B reaches the sixth spatial channel 16F. The second branch channel 63B can guide the coolant to the sixth spatial channel 16F. The sixth spatial channel 16F is the spatial channel 16 of the distribution destination.
The inclination angle of the first branched flow path 63A with respect to the merged flow path 62 and the inclination angle of the second branched flow path 63B with respect to the merged flow path 62 are equal.

In the inner end plate 11, one through-hole 41 (41A-41H) is formed at each position corresponding to the spatial flow path 16 (16A-16H) (see FIG. 4). The +X direction end of the heat exchange tube 30 is inserted into the through hole 41 . The +X direction end of the heat exchange tube 30 opens into the spatial flow path 16 . Therefore, the spatial channel 16 communicates with the refrigerant channel 34 of the heat exchange tube 30 .

When the refrigeration cycle device 1 shown in FIG. 1 performs heating operation, the heat exchanger 4 functions as an evaporator. In this case, the heat exchanger 4 converts the low-temperature, low-pressure gas-liquid two-phase refrigerant sent from the expansion device 5 into a low-pressure gaseous refrigerant by absorbing heat from the outside air and vaporizing it.

As shown in FIG. 7, at least part of the refrigerant that has flowed from the heat exchange tube 30 (30G) into the seventh spatial flow channel 16G flows into the confluence flow channel 62 through the first outlet flow channel 61A. At least part of the refrigerant that has flowed from the heat exchange tube 30 (30H) into the eighth spatial flow channel 16H flows into the confluence flow channel 62 through the second outlet flow channel 61B. The coolant that has flowed in from the seventh spatial flow channel 16G and the coolant that has flowed in from the eighth spatial flow channel 16H join together in the confluence flow channel 62 .

The coolant in the confluence channel 62 moves in the direction opposite to the direction of gravity (in the direction of the arrow shown in FIG. 8), collides with the upper surface of the direction changing portion 615, and flows through the two branch channels 63 into the fifth spatial channel 16E and the It is distributed to the sixth spatial flow channel 16F. Since the refrigerant is evenly distributed by the direction changing portion 615, it is possible to suppress uneven flow in the gas-liquid two-phase refrigerant. Therefore, the unevenness in the amount of refrigerant flowing into the plurality of branch flow paths 63 can be reduced.

As shown in FIG. 8, let the length of the branch flow path 63 be L [m]. Let D [m] be the hydraulic equivalent diameter of the branch flow path 63 . Let ρ [kg/m ³ ] be the density of the refrigerant. Let μ [Pa·s] be the viscosity of the refrigerant. Let W [kg/s] be the mass flow rate of the refrigerant in the confluence channel 62 . The mass flux G of the refrigerant in the confluence channel 62 is represented by "G=W/A" [kg/s/m ² ]. A is the cross-sectional area [m ² ] of the confluence channel 62 . The cross-sectional area of the channel is the area of the cross section orthogonal to the length direction of the channel.

The length L of the first branch channel 63A is also called _LA . The length L of the second branch channel _63B is also called LB. The hydraulic equivalent diameter D of the first branch flow path 63A is also called _DA . The hydraulic equivalent diameter _D of the second branch flow path 63B is also referred to as DB.
In addition, the lengths of the two branch flow paths 63 may be the same as each other, or may be different from each other. The hydraulic equivalent diameters of the two branch flow paths 63 may be the same or different.

The pressure loss ΔP of the branch flow path 63 is expressed by the following formula (1) (Darcy-Weisbach's formula).

"λ" is represented by the following equation (2) (Blazius equation).

　

By substituting formula (2) into formula (1), the following formula (3) is obtained.

From the equation (3), it can be seen that the pressure loss ΔP of the branch flow path 63 is greatly affected by Fp shown in the following equation (4).

The deviation (absolute value) of Fp of the two branched flow paths 63 is preferably 20% or less. For example, the Fp of the first branched channel 63 of the two branched channels 63 is Fp1. Let Fp2 be the Fp of the second branch flow path 63 . Let Fpav be the average of Fp1 and Fp2. |Fp1-Fpav|/Fpav×100 and |Fp2-Fpav|/Fpav×100 are both preferably 20 (%) or less. When the deviation (absolute value) of Fp is 20% or less, the unevenness in the amount of refrigerant flowing into the two branch flow paths 63 can be reduced.

In this heat exchanger, the first header 410 has the confluence distribution flow path 12, so that the refrigerant flowing through the first row of heat exchange tubes 30 and the refrigerant flowing through the second row of heat exchange tubes 30 are merged and distributed. It can be mixed and redistributed within channel 12 . Although there may be a difference in heat load between the heat exchange tubes 30 in the first row and the heat exchange tubes 30 in the second row, this heat exchanger can mix and redistribute the refrigerant. The difference in heat load can be reduced. Therefore, it is possible to suppress a decrease in heat exchange efficiency due to a difference in heat load. Therefore, the heat exchange efficiency in the heat exchanger can be enhanced.

(Fifth embodiment)
FIG. 9 is a plan view of the intermediate plate 514 of the first header 510 of the heat exchanger of the fifth embodiment. Configurations common to other embodiments are denoted by the same reference numerals, and descriptions thereof are omitted. As shown in FIG. 9, the intermediate plate 514 has a plurality of spatial channels 16 (16A-16H) and a confluence/distribution channel 512. As shown in FIG.

The confluence/distribution channel 512 has multiple (two) lead-out channels 561 , one confluence channel 62 , and multiple (two) branch channels 563 . The two outlet channels 561 are referred to as a first outlet channel 561A and a second outlet channel 561B, respectively. The first lead-out channel 561A extends in the +Y direction with the +Y direction end of the seventh spatial channel 16G as its base end. The second lead-out channel 561B extends in the -Y direction with the -Y direction end of the eighth spatial channel 16H as its base end. The first outlet flow path 561A and the second outlet flow path 561B are connected at their distal ends.

The confluence channel 62 extends straight in the +Z direction, which is the direction opposite to the direction of gravity, with the connection point between the tips of the first outlet channel 561A and the second outlet channel 561B as the base end. The confluence channel 62 has a smaller cross-sectional area than the outlet channel 561 .

The two branched flow paths 563 are called a first branched flow path 563A and a second branched flow path 563B, respectively. The first branched flow path 563A and the second branched flow path 563B are flow paths formed by branching the confluence flow path 62 into two.

The first branch channel 563A is L-shaped. The first branch channel 563A extends in the +Z direction with the end (tip) of the confluence channel 62 in the +Z direction as its base end, and changes direction in the -Y direction at the tip. The first branch channel 563A reaches the first spatial channel 16A. The first branch channel 563A can guide the coolant to the first spatial channel 16A (distribution destination spatial channel).

The second branch channel 563B is L-shaped. The second branch channel 563B extends in the +Y direction with the +Z direction end (tip) of the confluence channel 62 as the base end, and changes direction to the -Z direction at the tip. The second branch channel 563B reaches the sixth spatial channel 16F. The second branch channel 563B can guide the refrigerant to the sixth spatial channel 16F (distribution destination spatial channel).

In this heat exchanger, the first header 510 has the confluence distribution flow path 512, so that the refrigerant flowing through the first row of heat exchange tubes 30 and the refrigerant flowing through the second row of heat exchange tubes 30 are merged and distributed. It can be mixed and redistributed within channel 512 . Therefore, the heat exchange efficiency in the heat exchanger can be enhanced.

(Sixth embodiment)
FIG. 10 is a plan view of the intermediate plate 614 of the first header 610 of the heat exchanger of the sixth embodiment. Configurations common to other embodiments are denoted by the same reference numerals, and descriptions thereof are omitted. As shown in FIG. 10, the intermediate plate 614 has a plurality of spatial channels 16 (16A-16H) and a confluence/distribution channel 612. As shown in FIG.

The confluence/distribution channel 612 has multiple (two) lead-out channels 561 , one confluence channel 62 , and multiple (two) branch channels 663 . The number of branch channels 663 is two. The confluence channel 62 has a smaller cross-sectional area than the plurality of outlet channels 561 . The two branched channels 663 are referred to as a first branched channel 663A and a second branched channel 663B, respectively. The first branched flow path 663A and the second branched flow path 663B are flow paths formed by branching the confluence flow path 62 into two.

The first branch channel 663A extends obliquely upward with the end (tip) of the confluence channel 62 in the +Z direction as its base end, and reaches the first spatial channel 16A. The first branch channel 663A inclines upward in the -Y direction. The first branch channel 663A can guide the coolant to the first spatial channel 16A (distribution destination spatial channel).

The second branch channel 663B extends obliquely downward from the +Z direction end (tip) of the confluence channel 62 and reaches the sixth spatial channel 16F. The second branch flow path 663B is inclined downward toward the +Y direction. The second branch channel 663B can guide the refrigerant to the sixth spatial channel 16F (distribution destination spatial channel).

The first branched flow path 663A and the second branched flow path 663B have a cross-sectional area larger than that of the confluence flow path 62. Therefore, the refrigerant in the confluence flow path 62 is diffused by being released into flow paths having a large cross-sectional area when being distributed to the first branch flow path 663A and the second branch flow path 663B. Therefore, the refrigerant tends to become turbulent. Therefore, it is possible to suppress drift in the gas-liquid two-phase refrigerant.

In this heat exchanger, the first header 610 has the confluence distribution flow path 612, so that the refrigerant flowing through the first row of heat exchange tubes 30 and the refrigerant flowing through the second row of heat exchange tubes 30 are merged and distributed. It can be mixed and redistributed within channel 612 . Therefore, the heat exchange efficiency in the heat exchanger can be enhanced.

(Seventh embodiment)
FIG. 11 is a plan view of the intermediate plate 714 of the first header 710 of the heat exchanger of the seventh embodiment. Configurations common to other embodiments are denoted by the same reference numerals, and descriptions thereof are omitted. As shown in FIG. 11, the intermediate plate 714 has a plurality of spatial channels 16 (16A-16H) and a confluence/distribution channel 712. As shown in FIG.

The confluence/distribution channel 712 has multiple (two) lead-out channels 561 , one confluence channel 62 , and multiple (two) branch channels 763 . The confluence channel 62 extends straight in the +Z direction, which is the opposite direction to the direction of gravity, from the connecting point between the tips of the first outlet channel 561A and the second outlet channel 561B as the base end. The two branched channels 763 are referred to as a first branched channel 763A and a second branched channel 763B, respectively.

The first branch channel 763A is L-shaped. The first branch channel 763A extends in the -Y direction with the +Z direction end (tip) of the confluence channel 62 as the base end, changes direction at the tip to the +Z direction, and changes direction to the -Y direction at the tip. . The first branch channel 763A reaches the first spatial channel 16A. The first branch channel 763A can guide the refrigerant to the first spatial channel 16A (distribution destination spatial channel).

The second branch channel 763B is L-shaped. The second branch channel 763B extends in the +Y direction with the +Z direction end (tip) of the confluence channel 62 as the base end, and changes direction to the -Z direction at the tip. The second branch channel 763B reaches the sixth spatial channel 16F. The second branch channel 763B can guide the refrigerant to the sixth spatial channel 16F (distribution destination spatial channel).

A portion including the base ends of the branch flow paths 763A and 763B is the direction changing portion 715 . The direction changing portion 715 changes the flow direction of the coolant from the confluence flow path 62 . The direction changing portion 715 is formed along the Y direction. The direction changing portion 715 is longer than the Y-direction inner diameter D ₆₂ at the +Z-direction end (tip) of the confluence channel 62 . The formation direction of the direction changing portion 715 is orthogonal to the extension direction (Z direction) of the +Z direction end (tip) of the confluence channel 62 . The configuration of the branch flow paths 763A, 763B other than the direction changing portion 715 is the same as that of the branch flow paths 563A, 563B shown in FIG.

The coolant in the confluence channel 62 moves in the direction opposite to the direction of gravity (in the direction of the arrow shown in FIG. 11), collides with the upper surface of the direction changing portion 715, and flows through the two branch channels 763 into the first spatial channel 16A and the first spatial channel 16A. It is distributed to the sixth spatial flow channel 16F.

In this heat exchanger, since the direction changing portion 715 is orthogonal to the confluence flow path 62, the refrigerant flow can be directed to the two branch flow paths 763 without bias. Therefore, the refrigerant can be evenly distributed to the first branched flow path 763A and the second branched flow path 763B. Therefore, the unevenness in the amount of refrigerant flowing into the first branched flow path 763A and the second branched flow path 763B can be reduced.

Since the direction changing portion 715 is longer than the inner diameter D ₆₂ in the Y direction at the end (tip) in the +Z direction of the confluence channel 62, the refrigerant in the confluence channel 62 is allowed to reach the upper surface of the direction changing portion 715 having a sufficient length. hit. Thereby, the refrigerant flow can be evenly distributed to the two branch flow paths 763 .

(Eighth embodiment)
FIG. 12 is a plan view of the intermediate plate 814 of the first header 810 of the heat exchanger of the eighth embodiment. Configurations common to other embodiments are denoted by the same reference numerals, and descriptions thereof are omitted. As shown in FIG. 12, the intermediate plate 814 has a plurality of spatial channels 16 (16A-16H) and a confluence/distribution channel 812. As shown in FIG.

The confluence/distribution channel 812 has multiple (two) lead-out channels 561 , one confluence channel 62 , and multiple (two) branch channels 863 . The confluence channel 62 extends straight in the +Z direction, which is the opposite direction to the direction of gravity, from the connecting point between the tips of the first outlet channel 561A and the second outlet channel 561B as the base end. The two branched channels 863 are referred to as a first branched channel 863A and a second branched channel 863B, respectively.

The first branch flow path 863A extends in the -Y direction with the +Z direction end (tip) of the confluence flow path 62 as the base end, extends obliquely upward at the tip, and reaches the first spatial flow path 16A. The second branch flow channel 863B extends in the +Y direction from the +Z direction end (tip) of the confluence flow channel 62 as a base end, extends obliquely downward at the tip, and reaches the sixth spatial flow channel 16F.

A portion including the base ends of the branch flow paths 863A and 863B is the direction changing portion 815 . The direction changing portion 815 changes the flow direction of the coolant from the confluence channel 62 . The direction changing portion 815 is formed along the Y direction. The direction changing portion 815 is longer than the Y-direction inner diameter D ₆₂ at the +Z-direction end (tip) of the confluence channel 62 . The formation direction of the direction changing portion 815 is orthogonal to the extension direction (Z direction) of the +Z direction end (tip) of the confluence channel 62 . The configuration of the branch flow paths 863A, 863B other than the direction changing portion 815 is the same as that of the branch flow paths 663A, 663B shown in FIG.

In this heat exchanger, since the direction changing portion 815 is orthogonal to the confluence flow path 62, the flow direction of the refrigerant can be evenly directed to the first branch flow path 863A and the second branch flow path 863B. Therefore, the unevenness in the amount of refrigerant flowing into the first branched flow path 863A and the second branched flow path 863B can be reduced.

Since the direction changing portion 815 is longer than the inner diameter D ₆₂ in the Y direction at the +Z-direction end (tip) of the confluence channel 62, the coolant in the confluence channel 62 is allowed to reach the upper surface of the direction changing portion 815 having a sufficient length. hit. Thereby, the refrigerant flow can be evenly distributed to the two branch flow paths 863 .

(Ninth embodiment)
FIG. 13 is a plan view of the intermediate plate 914 of the first header 910 of the heat exchanger of the ninth embodiment. Configurations common to other embodiments are denoted by the same reference numerals, and descriptions thereof are omitted. As shown in FIG. 13, the intermediate plate 914 may have the same configuration as the intermediate plate 414 shown in FIG. 7 except that two gaps 920 are formed.

The gap 920 is linear and passes between the branch channel 63 and the spatial channel 16 closest to the branch channel 63 . The void 920 is formed by a through-hole penetrating through the intermediate plate 414 in the thickness direction. The two gaps 920 are referred to as a first gap 920A and a second gap 920B, respectively.

At least part of the first gap 920A is formed between the first branch channel 63A and the third spatial channel 16C. For example, the first gap 920A is formed parallel to the first branch flow path 63A. At least part of the second gap portion 920B is formed between the second branch channel 63B and the fourth spatial channel 16D. For example, the second gap 920B is formed parallel to the second branch flow path 63B.

In this heat exchanger, the gap 920 can suppress thermal interference from the spatial flow paths 16C and 16D. Therefore, the deviation of the flow rate of the refrigerant due to the phase change of the refrigerant in the branch flow path 63 can be reduced.

(comparative form)
FIG. 14 is a plan view of the intermediate plate 1014 of the first header 1010 of the heat exchanger of the comparative form. 15 is an enlarged plan view of intermediate plate 1014. FIG.
As shown in FIG. 14, the intermediate plate 1014 has a plurality of spatial channels 16 (16A-16H) and distribution channels 1012. As shown in FIG. The distribution channel 1012 has an outlet channel 1061 and two branch channels 1063 (1063A, 1063B). The outlet channel 1061 includes a first partial channel 1061A along the Y direction and a second partial channel 1061B along the Z direction. The lead-out channel 1061 is L-shaped. The first partial flow path 1061A is shorter than the pitch of the heat exchange tubes 30 (see P1 shown in FIG. 7).
As shown in FIG. 15, in this heat exchanger, there is a possibility that the liquid phase M1 and the gas phase M2 of the refrigerant may become unbalanced at the bent portion of the L-shaped outlet channel 1061 . Since the first partial channel 1061A is short, mixing of the liquid phase M1 and the gas phase M2 tends to be insufficient. Therefore, the bias between the liquid phase M1 and the gas phase M2 is maintained, and the amount of refrigerant distributed to the two branch flow paths 1063 may become uneven.

According to at least one embodiment described above, the header has a confluence/distribution channel. The confluence/distribution channel merges the refrigerants from the plurality of heat exchange tubes and distributes them to the other plurality of heat exchange tubes. In the heat exchanger of the embodiment, the refrigerant flowing through the plurality of heat exchange tubes can be mixed and redistributed within the converging distribution channel. A difference in heat load may occur between the plurality of heat exchange tubes, but in the heat exchanger of the embodiment, since the refrigerant can be mixed and redistributed, the difference in heat load can be reduced. Therefore, it is possible to suppress a decrease in heat exchange efficiency due to a difference in heat load. Therefore, the heat exchange efficiency in the heat exchanger can be enhanced.

Although several embodiments of the invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, replacements, and modifications can be made without departing from the scope of the invention. These embodiments and their modifications are included in the scope and spirit of the invention, as well as the scope of the invention described in the claims and equivalents thereof.

1 refrigeration cycle device 4 outdoor heat exchanger (heat exchanger)
10 First header (header)
12, 512, 612, 712, 812 Combined distribution channel 16 Space channel 30 Heat exchange tube 34 Refrigerant channel 62 Combined channel 63, 563, 663, 763, 863 Branch channel 63A, 563A, 663A, 763A, 863A First branch flow path (branch flow path)
63B, 563B, 663B, 763B, 863B Second branch channel (branch channel)
116, 216, 316 Spatial channel (confluence and distribution channel)
218, 318 Narrow portion 615, 715, 815 Direction changing portion 920 Gap portion L1 Length of merged flow path P1 Pitch of heat exchange tubes

Claims (7)

1. a plurality of heat exchange tubes formed with refrigerant flow paths through which the refrigerant flows;
   headers provided at the ends of the heat exchange tubes;
   with
   At least one of the headers is formed with a confluence/distribution flow path that merges the refrigerant from two or more of the plurality of heat exchange tubes and distributes the refrigerant to two or more of the other heat exchange tubes.
   Heat exchanger.
2. The confluence/distribution channel has a narrow portion through which the refrigerant flows,
   2. The heat exchanger of claim 1, wherein the constriction satisfies the formula:
   D1>2300μA1/W1
   (D1 is the hydraulic equivalent diameter [m] of the narrow portion. μ is the viscosity of the refrigerant [Pa·s]. A1 is the cross-sectional area [m ² ] of the narrow portion. W1 is , is the mass flow rate [kg/s] of the refrigerant flowing through the narrow portion.)
3. At least some of the plurality of heat exchange tubes are arranged in multiple stages,
   a plurality of spatial channels communicating with the refrigerant channels of the heat exchange tubes are formed in the header;
   The confluence/distribution channel includes a confluence channel for merging the refrigerant from two or more of the plurality of spatial channels, and a plurality of branch channels branched from the confluence channel,
   the branch channel distributes the refrigerant from the confluence channel to two or more of the other spatial channels;
   3. The heat exchanger according to claim 1, wherein said confluence channel is formed along the vertical direction, and the length of said confluence channel is longer than the pitch of said heat exchange tubes arranged in a plurality of stages.
4. the portion including the base end of the branch flow path is a direction changing portion that changes the flow direction of the refrigerant from the confluence flow path,
   The direction changing part is orthogonal to the extending direction at the tip of the merged flow path,
   4. The heat exchanger according to claim 3, wherein the length of said direction changing portion is longer than the inner diameter at the tip of said confluence flow path.
5. 5. The heat exchanger according to claim 3, wherein the deviation (absolute value) of Fp shown below in the plurality of branch flow paths is 20% or less.
   

   

   (L indicates the length [m] of the branch flow path. G indicates the mass flux [kg/s/m ² ] of the refrigerant in the combined flow path. D is the hydraulic equivalent diameter of the branch flow path. [m] is shown.)
6. The heat exchanger according to any one of claims 3 to 5, wherein the header has a gap formed between the branch channel and the spatial channel.
7. A refrigeration cycle apparatus having the heat exchanger according to any one of claims 1 to 6.

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