Heat exchanger and refrigeration cycle device

Abstract

To provide a heat exchanger capable of enhancing heat exchange efficiency, and to provide a refrigeration cycle device.SOLUTION: A heat exchanger includes a plurality of heat exchange tubes and a header. The heat exchange tube is formed with a refrigerant flow channel where a refrigerant flows. The header is disposed in the end of the heat exchange tube. A plurality of space flow channels, a confluent flow channel and a plurality of branch flow channels are formed in one or more headers. The plurality of space flow channels are communicated with the heat exchange tube. The confluent flow channel makes the refrigerants joining together flow. The plurality of branch flow channels are branched from the confluent flow channel. The plurality of branch flow channels are communicated with the plurality of space flow channels. The confluent flow channel is formed along the vertical direction. The branch flow channel extends obliquely downward from the tip of the confluent flow channel to the space flow channel.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] An embodiment of the present invention relates to a heat exchanger and a refrigeration cycle apparatus. [Background technology]

[0002] A header-type heat exchanger has a plurality of heat exchange tubes and a header. The heat exchange tubes have a refrigerant flow path. The header is provided at the end of the heat exchange tubes. The header has a flow path through which the refrigerant flows. For example, when heat exchange tubes are arranged in multiple rows, the heat loads on the multiple heat exchange tubes may differ, and in this case, the heat exchange efficiency of the heat exchanger may decrease due to excessive heat loads on some of the heat exchange tubes. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 8-313115 Summary of the Invention [Problem to be solved by the invention]

[0004] An object of the present invention is to provide a heat exchanger and a refrigeration cycle device that can improve heat exchange efficiency. [Means for solving the problem]

[0005] The heat exchanger of the embodiment has a plurality of heat exchange tubes and a header. The heat exchange tubes are formed with refrigerant flow paths through which a refrigerant flows. The header is provided at an end of the heat exchange tubes. At least one of the headers is formed with a plurality of spatial flow paths, a merging flow path, and a plurality of branch flow paths. The spatial flow paths are in communication with the heat exchange tubes. The merging flow path is From two or more of the spatial channelsThe merged refrigerant flows through the branch flow paths. The branch flow paths branch off from the merge flow path. The branch flow paths communicate with the spatial flow paths. The merge flow path is formed along the up-down direction. The branch flow paths extend obliquely downward from the tip of the merge flow path toward the spatial flow path. [Brief explanation of the drawings]

[0006] [Figure 1] 1 is a schematic configuration diagram of a refrigeration cycle device according to an embodiment; [Figure 2] FIG. 1 is a perspective view of a heat exchanger according to a first embodiment. [Figure 3] FIG. 2 is an exploded perspective view of the heat exchanger according to the first embodiment. [Figure 4] FIG. 3 is a plan view of an intermediate plate of a first header of the heat exchanger according to the first embodiment. [Figure 5] FIG. 10 is a plan view of an intermediate plate of a first header of a heat exchanger according to a second embodiment. [Figure 6] FIG. 11 is a plan view of an intermediate plate of a first header of a heat exchanger according to a third embodiment. [Figure 7] FIG. 10 is a plan view of an intermediate plate of a first header of a heat exchanger according to a fourth embodiment. [Figure 8] FIG. 10 is an enlarged plan view of an intermediate plate of a first header of a heat exchanger according to a fourth embodiment. [Figure 9] FIG. 11 is a plan view of an intermediate plate of a first header of a heat exchanger according to a fifth embodiment. [Figure 10] FIG. 13 is a plan view of an intermediate plate of a first header of a heat exchanger according to a sixth embodiment. [Figure 11] FIG. 13 is a plan view of an intermediate plate of a first header of a heat exchanger according to a seventh embodiment. [Figure 12] FIG. 13 is a plan view of an intermediate plate of a first header of a heat exchanger according to an eighth embodiment. [Figure 13] FIG. 13 is a plan view of an intermediate plate of a first header of the heat exchanger of the ninth embodiment. [Figure 14] FIG. 10 is a plan view of an intermediate plate of a first header of a heat exchanger according to a comparative example. [Figure 15] FIG. 10 is an enlarged plan view of an intermediate plate of a first header of a heat exchanger of a comparative example. DETAILED DESCRIPTION OF THE INVENTION

[0007] Hereinafter, a heat exchanger and a refrigeration cycle device according to an embodiment will be described with reference to the drawings.

[0008] (First embodiment) FIG. 1 is a schematic diagram of a refrigeration cycle device according to an embodiment. As shown in Fig. 1, the refrigeration cycle apparatus 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. The components of the refrigeration cycle apparatus 1 are connected by piping 7. In Fig. 1, the flow direction of the refrigerant (heat medium) during cooling operation is indicated by solid arrows, and the flow direction of the refrigerant during heating operation is indicated by dashed arrows.

[0009] The compressor 2 comprises a compressor main body 2A and an accumulator 2B. The compressor main body 2A compresses the low-pressure gas refrigerant taken in to produce high-temperature, high-pressure gas refrigerant. The accumulator 2B separates the gas-liquid two-phase refrigerant and supplies the gas refrigerant to the compressor main body 2A.

[0010] The four-way valve 3 reverses the flow direction of the refrigerant to switch between cooling and heating operation. During cooling operation, the refrigerant flows through the compressor 2, four-way valve 3, outdoor heat exchanger 4, expansion device 5, and indoor heat exchanger 6 in this order. At this time, the outdoor heat exchanger 4 functions as a condenser, and the indoor heat exchanger 6 functions as an evaporator.

[0011] During heating operation, the refrigerant flows through the compressor 2, four-way valve 3, indoor heat exchanger 6, expansion device 5, and outdoor heat exchanger 4 in this order. At this time, the indoor heat exchanger 6 functions as a condenser, and the outdoor heat exchanger 4 functions as an evaporator.

[0012] The condenser converts the high-temperature, high-pressure gas refrigerant discharged from the compressor 2 into high-pressure liquid refrigerant by condensing it through heat transfer to the outside air. The expansion device 5 reduces the pressure of the high-pressure liquid refrigerant sent from the condenser, converting it into low-temperature, low-pressure two-phase gas-liquid refrigerant. The evaporator converts the low-temperature, low-pressure two-phase gas-liquid refrigerant sent from the expansion device 5 into low-pressure gas refrigerant by absorbing heat from the outside air and vaporizing it.

[0013] In the refrigeration cycle device 1, the refrigerant, which is the working fluid, circulates while changing phase between gaseous and liquid refrigerants. The refrigerant releases heat during the phase change from gaseous to liquid refrigerant. The refrigerant absorbs heat during the phase change from liquid to gaseous refrigerant. The refrigeration cycle device 1 performs heating, cooling, defrosting, etc. by utilizing the heat release or absorption of the refrigerant.

[0014] 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 apparatus 1 will be described as an example.

[0015] The positional relationship of the heat exchanger 4 will be provisionally defined based on Figures 2 and 3. The X, Y, and Z directions are defined as follows: The Z direction is the longitudinal direction (extension 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 (extension direction) of the heat exchange tube. For example, the X direction is the horizontal direction. 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 the horizontal direction. The YZ plane is the plane formed by the Y and Z directions.

[0016] 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 −X direction end of the heat exchange tube 30.

[0017] The first header 10 and the second header 20 are formed in the shape of a flat plate 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 first header 10 and the second header 20 are shaped like a rectangle with the longitudinal direction along the Z direction. The first header 10 and the second header 20 are formed from a material with high thermal conductivity and low specific gravity. Examples of "materials with high thermal conductivity and low specific gravity" include metals such as aluminum and aluminum alloys.

[0018] 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 placed on the surface of the intermediate plate 14 on the -X direction side. The outer end plate 17 is placed on the surface of the intermediate plate 14 on the +X direction side.

[0019] FIG. 4 is a plan view of the intermediate plate 14. As shown in FIG. 4, the intermediate plate 14 has a plurality of spatial flow paths 16 (16A, 16B, 16G, 16H) and a spatial flow path 116. The spatial flow paths 16, 116 serve as flow paths for the refrigerant. The spatial flow paths 16, 116 are formed by through holes that penetrate the intermediate plate 14 in the thickness direction. The openings of the spatial flow paths 16, 116 are closed by the inner end plate 11 and the outer end plate 17 (see FIG. 3). The spatial flow path 116 is an example of a confluence / division flow path.

[0020] The multiple 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 channels 16 are elliptical when viewed from the X direction. The "elliptical shape" is a shape formed by two straight lines that are parallel to and face each other, and two curved lines. The curved lines are curved convex shapes (e.g., semicircular, elliptical arc, etc.) that connect the ends of the two straight lines. The major axis direction of the spatial channels 16 is parallel to the Y direction. The multiple spatial channels 16 are formed at a distance from each other. The multiple spatial channels 16 have the same shape.

[0021] The first spatial flow path 16A and the second spatial flow path 16B are formed side by side in the Y direction with an interval in between them. The second spatial flow path 16B is located on the +Y direction side of the first spatial flow path 16A.

[0022] The spatial flow path 116 is located at a lower position than the first spatial flow path 16A and the second spatial flow path 16B. The spatial flow path 116 is located away from the first spatial flow path 16A and the second spatial flow path 16B on the -Z direction side. The spatial flow path 116 has an elliptical shape when viewed from the X direction. The major axis direction of the spatial flow path 116 is parallel to the Y direction. The major axis of the spatial flow path 116 is larger than the major axis of the spatial flow path 16.

[0023] The third spatial flow path 16G and the fourth spatial flow path 16H are located at a lower position than the spatial flow path 116. The third spatial flow path 16G and the fourth spatial flow path 16H are located away from the spatial flow path 116 on the -Z direction side. The third spatial flow path 16G and the fourth spatial flow path 16H are formed side by side in the Y direction with an interval between them in the Y direction. The fourth spatial flow path 16H is located on the +Y direction side of the third spatial flow path 16G.

[0024] The inner end plate 11 has one through hole 41 formed at a position corresponding to each of the spatial channels 16 (16A, 16B, 16G, 16H). The through holes 41 are slit-shaped along the Y direction. The +X-direction ends of the heat exchange tubes 30 are inserted into the through holes 41. The +X-direction ends of the heat exchange tubes 30 open to the spatial channels 16. Therefore, each spatial channel 16 communicates with the refrigerant channel 34 of one heat exchange tube 30.

[0025] 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 referred to as through holes 41A, 41B, 41G, and 41H, respectively.

[0026] Four through holes 41 are formed in the inner end plate 11 at positions corresponding to the spatial flow paths 116. The +X-direction ends of the heat exchange tubes 30 are inserted into the through holes 41. The +X-direction ends of the heat exchange tubes 30 open to the spatial flow paths 116. Therefore, the spatial flow paths 116 communicate with the refrigerant flow paths 34 of the four heat exchange tubes 30.

[0027] The four through holes 41 formed in the spatial flow path 116 are through holes 41C, 41D, 41E, and 41F. The through holes 41C and 41D are formed side by side in the Y direction with a gap between them. The through hole 41D is located on the +Y direction side of the through hole 41C. The through holes 41E and 41F are located away from the through holes 41C and 41D on the -Z direction side. The through holes 41E and 41F are formed side by side in the Y direction with a gap between them. The through hole 41F is located on the +Y direction side of the through hole 41E.

[0028] 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 to 41H are referred to as heat exchange tubes 30A to 30H, respectively.

[0029] 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, respectively (see Fig. 2). One end of the first refrigerant port 51 opens to the third spatial flow path 16G. The other end of the first refrigerant port 51 opens to the fourth spatial flow path 16H. These openings serve as an inlet port for introducing the refrigerant into the heat exchanger 4 and an outlet port for discharging the refrigerant from the heat exchanger 4.

[0030] Two through holes 43 are formed in the outer end plate 17. Tubular second refrigerant ports 52 are inserted into the through holes 43, respectively (see FIG. 2). One end of the second refrigerant port 52 opens to the first spatial flow path 16A. The other end of the second refrigerant port 52 opens to the second spatial flow path 16B. These openings serve as an inlet port for introducing the refrigerant into the heat exchanger 4 and an outlet port for discharging the refrigerant from the heat exchanger 4.

[0031] The second header 20 has a pair of small headers 20A, 20B. The small headers 20A, 20B are arranged side by side in the Y direction. The small headers 20A, 20B each have an inner end plate 21, an intermediate plate 24, and an outer end plate 27. The inner end plate 21 is placed on the surface of the intermediate plate 24 on the +X direction side. The outer end plate 27 is placed on the surface of the intermediate plate 24 on the -X direction side.

[0032] The intermediate plate 24 has a plurality of spatial flow paths (not shown). These spatial flow paths serve as paths for the refrigerant. These spatial flow paths are formed by through holes that penetrate the intermediate plate 24 in the thickness direction. The openings of these spatial flow paths are closed by the inner end plate 21 and the outer end plate 27.

[0033] The heat exchange tube 30 is formed in a flattened tubular shape. That is, the dimension of the heat exchange tube 30 in the Y direction is larger than the dimension in the Z direction. The cross section (YZ cross section) of the heat exchange tube 30 perpendicular to the longitudinal direction is oval. The heat exchange tube 30 extends in the X direction. A refrigerant flow path 34 is formed inside the heat exchange tube 30. The heat exchange tube 30 is made of a material that has high thermal conductivity and a low specific gravity. Examples of "materials that have high thermal conductivity and a low specific gravity" include metals such as aluminum and aluminum alloys.

[0034] At least some of the heat exchange tubes 30 are arranged in parallel with gaps 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 with gaps in the Z direction. That is, the four heat exchange tubes 30 (30A, 30C, 30E, 30G) are arranged in multiple tiers (four tiers). 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 with gaps in the Z direction. That is, the four heat exchange tubes 30 (30B, 30D, 30F, 30H) are arranged in multiple tiers (four tiers).

[0035] The eight heat exchange tubes 30 are arranged in two rows. When viewed from the X direction, the eight heat exchange tubes 30 are arranged in a 2 x 4 matrix. The heat exchange tubes 30A, 30C, 30E, and 30G are referred to as the heat exchange tubes 30 in the first row. The heat exchange tubes 30B, 30D, 30F, and 30H are referred to as the heat exchange tubes 30 in the second row. The number of rows formed by the heat exchange tubes 30 is not limited to 2. The number of rows formed by the heat exchange tubes 30 may be any number (2 or more).

[0036] The −X direction ends of the heat exchange tubes 30 are inserted into the through holes 45 formed in the second header 20. As a result, the −X direction ends of the refrigerant flow paths 34 of the heat exchange tubes 30 open to the spatial flow paths 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.

[0037] The gap between the first header 10 and the heat exchange tubes 30 and the gap between the second header 20 and the heat exchange tubes 30 are sealed by brazing or the like.

[0038] An outside air flow path is formed along the Y direction between adjacent heat exchange tubes 30 in the vertical direction. The heat exchanger 4 circulates outside air through the outside air flow path using a blower fan (not shown) or the like. The heat exchanger 4 exchanges heat between the outside air flowing through the outside air flow path and the refrigerant flowing through the refrigerant flow path 34. The heat exchange is performed indirectly via the heat exchange tubes 30.

[0039] 1 performs heating operation, the heat exchanger 4 functions as an evaporator. In this case, the heat exchanger 4 absorbs heat from the outside air to vaporize the low-temperature, low-pressure gas-liquid two-phase refrigerant fed from the expansion device 5, thereby converting it into a low-pressure gas refrigerant.

[0040] As shown in Fig. 4, for example, the refrigerant flows from the two first refrigerant ports 51 (see Fig. 2) into the third spatial flow path 16G and the fourth spatial flow path 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 then flows into different spatial flow paths of the second header 20. The refrigerant flows through the heat exchange tubes 30E and 30F in the +X direction, and then flows into the spatial flow path 116 of the first header 10.

[0041] 4, the refrigerant flowing in from the heat exchange tube 30E and the refrigerant flowing in from the heat exchange tube 30F join together in the spatial flow path 116. The refrigerant in the spatial flow path 116 is distributed to the heat exchange tube 30C and the heat exchange tube 30D.

[0042] 3, the refrigerant distributed to the heat exchange tubes 30C, 30D flows through the heat exchange tubes 30C, 30D in the −X direction and each flows into a different spatial flow path in the second header 20. The refrigerant flows through the heat exchange tubes 30A, 30B in the +X direction and each flows into the first spatial flow path 16A and the second spatial flow path 16B of the first header 10. The refrigerant flows out of the system from the second refrigerant port 52 (see FIG. 2).

[0043] In this example, the refrigerant is introduced through the first refrigerant port 51 (see Figure 2), passes through the heat exchange tubes 30, travels back and forth between the first header 10 and the second header 20, and flows out through the second refrigerant port 52 (see Figure 2).

[0044] In the heat exchanger 4, the first header 10 has spatial flow paths (confluence / distribution flow paths) 116. The spatial flow paths 116 converge refrigerant from two heat exchange tubes 30 (30E, 30F) and distribute the refrigerant 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 paths 116.

[0045] Although a difference in heat load may occur between the first row of heat exchange tubes 30 and the second row of heat exchange tubes 30, the heat exchanger 4 can mix and redistribute the refrigerant, thereby reducing the difference in heat load. This prevents the heat exchange efficiency from decreasing due to the difference in heat load, thereby improving the heat exchange efficiency in the heat exchanger 4.

[0046] For comparison, a heat exchanger is assumed in which an external pipe line (confluence / branch pipe line) for mixing and redistributing the refrigerant is provided in the first header. A heat exchanger with this structure is inferior in terms of storage capacity because the external pipe line protrudes from the first header. In contrast, the heat exchanger 4 of the embodiment does not require an external pipe line because the refrigerant is mixed and redistributed within the first header 10. Therefore, the heat exchanger 4 shown in FIG. 2 can be made compact and is excellent in terms of storage capacity. Another advantage of the heat exchanger 4 is that it is lightweight because it does not have an external pipe line.

[0047] In this embodiment, the refrigerant from two heat exchange tubes is joined and distributed to the other two heat exchange tubes, but the number of refrigerants that are joined is not limited to two and may be multiple (any number greater than or equal to two).The number of heat exchange tubes that distribute the refrigerant is also not limited to two and may be multiple (any number greater than or equal to two).In other words, the joining and distribution flow path joins the refrigerant supplied from two or more of the multiple heat exchange tubes and distributes it to the other two or more heat exchange tubes. The number of converging / distributing channels formed in the first header is not limited to one, and may be multiple (any number greater than or equal to two). The converging / distributing channel may be formed in the intermediate plate of the second header. The number of converging / distributing channels formed in the second header may be one or multiple (any number greater than or equal to two). The converging / distributing channel is formed in at least one of the first header and the second header. The converging / distributing channel may be formed in either the first header or the second header, or may be formed in both.

[0048] (Second embodiment) 5 is a plan view of the intermediate plate 214 of the first header 210 of the heat exchanger of the second embodiment. Components common to other embodiments are given the same reference numerals and description thereof will be omitted.

[0049] As shown in Fig. 5, the intermediate plate 214 has spatial flow paths 16 and spatial flow paths 216. The heat exchanger of the second embodiment has the same configuration as the heat exchanger of the first embodiment shown in Fig. 4, except that it has spatial flow paths 216 instead of spatial flow paths 116. The spatial flow paths 216 are an example of a confluence / division flow path.

[0050] The spatial flow path 216 has an elliptical shape when viewed from the X direction. The major axis direction of the spatial flow path 216 is parallel to the Y direction. A protrusion 217 is formed at each end of the spatial flow path 216. The pair of protrusions 217 protrude in directions approaching each other along the Y direction. The protrusion 217 is formed at approximately the center in the height direction of the spatial flow path 216. The protrusion 217 has a U-shape combining a pair of straight portions and a curved portion. The pair of straight portions are parallel to and face each other. The curved portion is curved convexly (for example, semicircular). Between the tip of one protrusion 217 and the tip of the other protrusion 217 is a narrow portion 218. The narrow portion 218 narrows the refrigerant flow path.

[0051] The narrowed portion 218 preferably satisfies the following formula: D1>2300μA1 / W1 (D1 is the hydraulic equivalent diameter [m] of the narrowed portion 218. μ is the viscosity of the refrigerant [Pa·s]. A1 is the cross-sectional area [m 2 W1 is the mass flow rate [kg / s] of the refrigerant flowing through the narrow portion 218. The cross-sectional area of ​​narrow portion 218 is the area of ​​the flow path in a cross section perpendicular to the flow direction of the refrigerant in narrow portion 218. The flow direction of the refrigerant in narrow portion 218 is the +Z direction. The cross section perpendicular to the flow direction of the refrigerant in narrow portion 218 is along a horizontal plane.

[0052] When the narrow portion 218 satisfies this formula, the refrigerant flowing through the narrow portion 218 tends to become turbulent, so that uneven flow of the refrigerant in a gas-liquid two-phase state within the spatial flow path 216 can be suppressed.

[0053] The refrigerant flowing in from the heat exchange tube 30E and the refrigerant flowing in from the heat exchange tube 30F join together in the spatial flow path 216. As shown by the arrows in Fig. 5, the refrigerant rises in the narrowed portion 218 in the +Z direction (opposite the direction of gravity), collides with the upper surface of the spatial flow path 216, splits into left and right, and is distributed to the heat exchange tube 30C and the heat exchange tube 30D.

[0054] In this heat exchanger, the first header 210 has spatial channels 216, which allows 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 to be mixed and redistributed within the spatial channels 216. This increases the heat exchange efficiency of the heat exchanger.

[0055] In this heat exchanger, a narrow portion 218 is formed in the spatial flow path 216. The refrigerant is first concentrated by passing through the narrow portion and then diffused by being released, which makes it more likely to become a turbulent flow. Therefore, it is possible to suppress uneven flow of the refrigerant in a gas-liquid two-phase state within the spatial flow path 216.

[0056] (Third embodiment) 6 is a plan view of an intermediate plate 314 of a first header 310 of a heat exchanger according to the third embodiment. Components common to other embodiments are given the same reference numerals and will not be described. 6, the intermediate plate 314 has spatial flow channels 16 and spatial flow channels 316. The spatial flow channels 316 are an example of confluence / division channels.

[0057] The spatial flow path 316 has an elliptical shape. The spatial flow path 316 has a pair of straight portions 316a and a pair of curved portions 316b. The pair of straight portions 316a are parallel to and face each other. One curved portion 316b connects one end of the two straight portions 316a. The other curved portion 316b connects the other end of the two straight portions 316a. The curved portions 316b are curved convexly (e.g., semicircular). The major axis direction of the spatial flow path 316 is inclined with respect to the Y direction. The spatial flow path 316 is inclined so that the curved portion 316b on the upstream side of the flow of outside air in the above-mentioned outside air flow path (the outside air flow path formed between adjacent heat exchanger tubes 30) is positioned higher than the curved portion 316b on the downstream side.

[0058] A protrusion 317 is formed on each of the pair of straight portions 316a. The pair of protrusions 317 protrude toward each other along the minor axis direction of the spatial flow path 316. The protrusion 317 is formed approximately in the center of the straight portion 316a in the longitudinal direction. The protrusion 317 has a U-shape that combines a pair of straight portions and a curved portion. The pair of straight portions are parallel to and face each other. The curved portion is curved convexly (for example, semicircular). Between the tip of one protrusion 317 and the tip of the other protrusion 317 is a narrow portion 318.

[0059] The narrowed portion 318 preferably satisfies the following formula: D2>2300μA2 / W2 (D2 is the hydraulic equivalent diameter [m] of the narrowed portion 318. μ is the viscosity of the refrigerant [Pa·s]. A2 is the cross-sectional area [m 2 W2 is the mass flow rate [kg / s] of the refrigerant flowing through the narrow portion 218. The cross-sectional area of ​​the narrowed portion 318 is the area of ​​the flow path in the cross section perpendicular to the direction of the flow of the refrigerant in the narrowed portion 318. When the narrow portion 318 satisfies this formula, the refrigerant flowing through the narrow portion 318 tends to become turbulent, so that uneven flow of the refrigerant in a gas-liquid two-phase state within the spatial flow path 316 can be suppressed.

[0060] The refrigerant flows from the first refrigerant ports into the second spatial flow passage 16B and the fourth spatial flow passage 16H of the first header 10. The refrigerant flows through the heat exchange tubes 30B and 30H in the −X direction and enters different spatial flow passages in the second header 20. The refrigerant flows through the heat exchange tubes 30D and 30F in the +X direction and enters the spatial flow passage 316 of the first header 10.

[0061] The refrigerant flowing in from the heat exchange tube 30D and the refrigerant flowing in from the heat exchange tube 30F join together in the spatial flow path 316. As shown by the arrows in Figure 6, the refrigerant flows diagonally downward and passes through the narrowed portion 318, where it collides with the inner surface of the curved portion 316b, splits into upper and lower portions, and is distributed to the heat exchange tubes 30C and 30E. Because the refrigerant passing through the narrowed portion 318 flows diagonally downward, its flow rate is likely to be higher due to the influence of gravity than when it flows upward (see Figure 5).

[0062] The refrigerant distributed to the heat exchange tubes 30C, 30E flows through the heat exchange tubes 30C, 30E in the -X direction and each flows into a different spatial flow path in the second header 20. The refrigerant flows through the heat exchange tubes 30A, 30G in the +X direction and each flows into the first spatial flow path 16A and the third spatial flow path 16G of the first header 10. The refrigerant flows out from the second refrigerant port.

[0063] In this heat exchanger, the first header 310 has spatial channels 316, which allows 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 to be mixed and redistributed within the spatial channels 316. This increases the heat exchange efficiency of the heat exchanger.

[0064] In this heat exchanger, narrow portions 318 are formed in the spatial flow paths 316, and the spatial flow paths 316 are inclined. Therefore, the refrigerant passes through the narrow portions 318 with momentum due to the influence of gravity. In this heat exchanger, the refrigerant passes through the narrow portions with momentum, so the refrigerant is first concentrated and then released, causing it to diffuse. Therefore, the refrigerant is prone to turbulent flow. This makes it possible to suppress uneven flow of the refrigerant in a gas-liquid two-phase state within the spatial flow paths 316.

[0065] In this embodiment, the spatial flow path 316 is formed to be inclined, but the major axis direction of the spatial flow path 316 may be parallel to the Y direction.

[0066] (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 the intermediate plate 414. Components common to other embodiments are given the same reference numerals and will not be described.

[0067] As shown in FIG. 7, the intermediate plate 414 has a plurality of spatial channels 16 (16A to 16H) and confluence / division channels 12. The spatial channels 16 are formed by through holes that penetrate the intermediate plate 414 in the thickness direction. The plurality of spatial channels 16 include a first spatial channel 16A to an eighth spatial channel 16H. The spatial channels 16 (16A to 16H) have an elliptical shape when viewed from the X direction. The major axis direction of the spatial channels 16 is parallel to the Y direction. The plurality of spatial channels 16 are formed to be spaced apart from one another. The plurality of spatial channels 16 have the same shape.

[0068] The first spatial flow path 16A and the second spatial flow path 16B are formed side by side in the Y direction with an interval in between them. The second spatial flow path 16B is located on the +Y direction side of the first spatial flow path 16A.

[0069] The third spatial flow path 16C and the fourth spatial flow path 16D are located lower than the first spatial flow path 16A and the second spatial flow path 16B, respectively. The third spatial flow path 16C and the fourth spatial flow path 16D are located away from the first spatial flow path 16A and the second spatial flow path 16B on the -Z direction side. The third spatial flow path 16C and the fourth spatial flow path 16D are formed side by side in the Y direction with an interval between them in the Y direction. The fourth spatial flow path 16D is located on the +Y direction side of the third spatial flow path 16C.

[0070] The fifth spatial flow path 16E and the sixth spatial flow path 16F are located lower than the third spatial flow path 16C and the fourth spatial flow path 16D, respectively. The fifth spatial flow path 16E and the sixth spatial flow path 16F are located away from the third spatial flow path 16C and the fourth spatial flow path 16D on the -Z direction side. The fifth spatial flow path 16E and the sixth spatial flow path 16F are formed side by side in the Y direction with an interval between them. The sixth spatial flow path 16F is located on the +Y direction side of the fifth spatial flow path 16E.

[0071] The seventh spatial flow path 16G and the eighth spatial flow path 16H are located lower than the fifth spatial flow path 16E and the sixth spatial flow path 16F, respectively. The seventh spatial flow path 16G and the eighth spatial flow path 16H are located away from the fifth spatial flow path 16E and the sixth spatial flow path 16F in the -Z direction. The seventh spatial flow path 16G and the eighth spatial flow path 16H are formed side by side in the Y direction with an interval between them. The eighth spatial flow path 16H is located on the +Y direction side of the seventh spatial flow path 16G.

[0072] The spatial channels 16A, 16C, 16E, and 16G are arranged side by side in the Z direction. The spatial 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 side by side in a 2 x 4 matrix. The spatial channels 16A, 16C, 16E, and 16G are referred to as the spatial channels 16 in the first row. The spatial channels 16B, 16D, 16F, and 16H are referred to as the spatial channels 16 in the second row. The pitch P1 is the difference in height between the central axes of the heat exchange tubes 30 adjacent to each other in the vertical direction. The number of rows formed by the spatial channels 16 is not limited to 2. The number of rows formed by the spatial channels 16 may be any number (2 or more).

[0073] 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 refrigerant from the seventh spatial channel 16G and the eighth spatial channel 16H to the fifth spatial channel 16E and the sixth spatial channel 16F.

[0074] The confluence / distribution flow path 12 has a plurality of outlet flow paths 61, one confluence flow path 62, and a plurality of branch flow paths 63. The number of outlet flow paths 61 is two. The number of branch flow paths 63 is two. Note that the number of outlet flow paths and branch flow paths is not limited to two, and may be any number equal to or greater than two.

[0075] A portion including the base ends of branch flow paths 63A and 63B is direction change portion 615. Direction change portion 615 is a curved flow path including the base end portions of branch flow paths 63A and 63B. Direction change portion 615 changes the flow direction of the refrigerant from junction flow path 62.

[0076] The two outlet channels 61 are referred to as a first outlet channel 61A and a second outlet channel 61B. The first outlet channel 61A extends in the +Y direction from the +Y-direction end of the seventh spatial channel 16G as a base end. The first outlet channel 61A guides the refrigerant from the seventh spatial channel 16G. The second outlet channel 61B extends in the -Y direction from the -Y-direction end of the eighth spatial channel 16H as a base end. The second outlet channel 61B guides the refrigerant from the eighth spatial channel 16H. The first outlet channel 61A and the second outlet channel 61B are formed at the same height. The first outlet channel 61A and the second outlet channel 61B are connected at their tips.

[0077] The junction flow path 62 extends straight in the +Z direction, which is opposite to the direction of gravity, from the connection point between the tips of the first outlet flow path 61A and the second outlet flow path 61B as its base end. The junction flow path 62 is a flow path along the up-and-down direction. The junction flow path 62 is located closer to the +Y direction than the spatial flow paths 16 (16A, 16C, 16E, 16G) in the first row. The junction flow path 62 is located closer to the -Y direction than the spatial flow paths 16 (16B, 16D, 16F, 16H) in the second row. The junction flow path 62 merges refrigerant from two or more spatial flow paths 16 out of the multiple spatial flow paths 16.

[0078] In FIG. 7, the confluence flow path 62 is formed at an intermediate position, the same distance away from both the first row of spatial flow paths 16 (16A, 16C, 16E, 16G) and the second row of spatial flow paths 16 (16B, 16D, 16F, 16H). The length L1 of the confluence flow path 62 is greater than the pitch P1 of the heat exchange tubes 30 in the vertical direction. Since the length L1 is greater than the pitch P1, the confluence flow path 62 has a sufficient length. Therefore, the refrigerant in a gas-liquid two-phase state can be sufficiently mixed in the confluence flow path 62, and uneven flow of the refrigerant can be suppressed. Therefore, unevenness in the amount of refrigerant flowing into the multiple branch flow paths 63 can be reduced.

[0079] Since the length L1 of the junction flow path 62 is greater than the pitch P1 of the heat exchange tubes 30, the end (tip) in the +Z direction of the junction flow path 62 is located higher than the heat exchange tubes 30 connected to the spatial flow paths 16E, 16F. It is desirable that the end (tip) in the +Z direction of the junction flow path 62 be located higher than the spatial flow paths 16E, 16F.

[0080] The branch flow path 63 distributes the refrigerant from the junction flow path 62 to two or more other spatial flow paths 16 (two or more of the spatial flow paths 16 other than the spatial flow paths 16G and 16H). The two branch flow paths 63 are referred to as a first branch flow path 63A and a second branch flow path 63B, respectively. The first branch flow path 63A and the second branch flow path 63B are flow paths formed by branching the junction flow path 62 into two.

[0081] The first branch flow path 63A is a linear flow path that extends obliquely downward from the end (tip) of the junction flow path 62 in the +Z direction as its base end. The first branch flow path 63A is inclined downward as it goes in the -Y direction. The first branch flow path 63A reaches the fifth spatial flow path 16E. The first branch flow path 63A can guide the refrigerant to the fifth spatial flow path 16E. The fifth spatial flow path 16E is the spatial flow path 16 to which the refrigerant is distributed.

[0082] The second branch flow path 63B is a linear flow path that extends obliquely downward from the +Z direction end (tip) of the merging flow path 62 as its base end. The second branch flow path 63B is inclined downward as it goes in the +Y direction. The second branch flow path 63B reaches the sixth spatial flow path 16F. The second branch flow path 63B can guide the refrigerant to the sixth spatial flow path 16F. The sixth spatial flow path 16F is the spatial flow path 16 to which the refrigerant is distributed. The inclination angle of the first branch channel 63A relative to the junction channel 62 and the inclination angle of the second branch channel 63B relative to the junction channel 62 are equal.

[0083] The inner end plate 11 has one through-hole 41 (41A to 41H) formed at each position corresponding to the spatial flow paths 16 (16A to 16H) (see FIG. 4). The +X-direction ends of the heat exchange tubes 30 are inserted into the through-holes 41. The +X-direction ends of the heat exchange tubes 30 open to the spatial flow paths 16. Therefore, the spatial flow paths 16 communicate with the refrigerant flow paths 34 of the heat exchange tubes 30.

[0084] 1 performs heating operation, the heat exchanger 4 functions as an evaporator. In this case, the heat exchanger 4 absorbs heat from the outside air to vaporize the low-temperature, low-pressure gas-liquid two-phase refrigerant fed from the expansion device 5, thereby converting it into a low-pressure gas refrigerant.

[0085] 7, at least a portion of the refrigerant that flows from the heat exchange tube 30 (30G) into the seventh spatial flow path 16G flows into the confluence flow path 62 through the first outlet flow path 61A. At least a portion of the refrigerant that flows from the heat exchange tube 30 (30H) into the eighth spatial flow path 16H flows into the confluence flow path 62 through the second outlet flow path 61B. The refrigerant that flows from the seventh spatial flow path 16G and the refrigerant that flows from the eighth spatial flow path 16H are confluenced in the confluence flow path 62.

[0086] The refrigerant in the confluence flow path 62 moves in the direction opposite to the direction of gravity (the direction of the arrow shown in FIG. 8), collides with the upper surface of the direction changer 615, and is distributed to the fifth spatial flow path 16E and the sixth spatial flow path 16F by the two branch flow paths 63. The refrigerant is distributed without bias in pressure by the direction changer 615, so bias in the refrigerant in a gas-liquid two-phase state can be suppressed. Therefore, bias in the amount of refrigerant flowing into the multiple branch flow paths 63 can be reduced.

[0087] As shown in Fig. 8, the length of the branch flow path 63 is L [m]. The hydraulic equivalent diameter of the branch flow path 63 is D [m]. The density of the refrigerant is ρ [kg / m 3 ]. The viscosity of the refrigerant is μ [Pa·s]. The mass flow rate of the refrigerant in the confluence flow path 62 is W [kg / s]. The mass flux G of the refrigerant in the confluence flow path 62 is "G = W / A" [kg / s / m 2 A is the cross-sectional area [m2 The cross-sectional area of ​​a flow channel is the area of ​​a cross section perpendicular to the longitudinal direction of the flow channel.

[0088] The length L of the first branch flow path 63A is L A The length L of the second branch flow path 63B is L B The hydraulic equivalent diameter D of the first branch flow path 63A is D A The hydraulic equivalent diameter D of the second branch flow path 63B is D B It is also called. The lengths of the two branch flow paths 63 may be the same or different from each other. The hydraulic equivalent diameters of the two branch flow paths 63 may be the same or different from each other.

[0089] The pressure loss ΔP in the branch flow path 63 is expressed by the following formula (1) (Darcy-Weisbach formula).

[0090]

number

[0091] "λ" is expressed by the following formula (2) (Blasius' formula).

[0092]

number

[0093] Substituting equation (2) into equation (1) gives the following equation (3).

[0094]

number

[0095] From 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).

[0096]

number

[0097] The deviation (absolute value) of Fp between the two branch flow paths 63 is preferably 20% or less. For example, let Fp1 be the Fp of the first branch flow path 63 of the two branch flow paths 63. Let Fp2 be the Fp of the second branch flow path 63. Let Fpav be the average of Fp1 and Fp2. It is preferable that |Fp1-Fpav| / Fpav×100 and |Fp2-Fpav| / Fpav×100 are both 20% or less. When the deviation (absolute value) of Fp is 20% or less, the imbalance in the amount of refrigerant flowing into the two branch flow paths 63 can be reduced.

[0098] In this heat exchanger, the first header 410 has the confluence / distribution flow path 12, so 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 confluence / distribution flow path 12. Although a difference in heat load may occur between the first row of heat exchange tubes 30 and the second row of heat exchange tubes 30, this heat exchanger allows for the mixing and redistribution of refrigerant, thereby reducing the difference in heat load. This prevents the heat exchange efficiency from decreasing due to the difference in heat load. This increases the heat exchange efficiency of the heat exchanger.

[0099] (Fifth embodiment) 9 is a plan view of an intermediate plate 514 of a first header 510 of a heat exchanger according to the fifth embodiment. Components common to other embodiments are denoted by the same reference numerals and will not be described further. As shown in FIG. 9, the intermediate plate 514 has a plurality of spatial flow paths 16 (16A to 16H) and a confluence / distribution flow path 512.

[0100] The confluence / division channel 512 has a plurality (two) of outlet channels 561, one confluence channel 62, and a plurality (two) of branch channels 563. The two outlet channels 561 are referred to as a first outlet channel 561A and a second outlet channel 561B. The first outlet channel 561A extends in the +Y direction from the +Y direction end of the seventh spatial channel 16G as a base end. The second outlet channel 561B extends in the -Y direction from the -Y direction end of the eighth spatial channel 16H as a base end. The first outlet channel 561A and the second outlet channel 561B are connected at their tips.

[0101] The junction channel 62 extends straight in the +Z direction, which is the opposite direction to the direction of gravity, from the connection point between the tips of the first outlet channel 561A and the second outlet channel 561B as its base end. The junction channel 62 has a smaller cross-sectional area than the outlet channel 561.

[0102] The two branch flow paths 563 are respectively referred to as a first branch flow path 563A and a second branch flow path 563B. The first branch flow path 563A and the second branch flow path 563B are flow paths formed by branching the junction flow path 62 into two.

[0103] The first branch flow path 563A is L-shaped. The first branch flow path 563A extends in the +Z direction with the +Z direction end (tip) of the junction flow path 62 as its base end, and changes direction to the -Y direction at the tip. The first branch flow path 563A reaches the first spatial flow path 16A. The first branch flow path 563A can guide the refrigerant to the first spatial flow path 16A (spatial flow path to which the refrigerant is distributed).

[0104] The second branch flow path 563B is L-shaped. The second branch flow path 563B extends in the +Y direction from the +Z-direction end (tip) of the junction flow path 62 as its base end, and changes direction to the -Z direction at the tip. The second branch flow path 563B reaches the sixth spatial flow path 16F. The second branch flow path 563B can guide the refrigerant to the sixth spatial flow path 16F (spatial flow path to which the refrigerant is distributed).

[0105] 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 can be mixed and redistributed within the confluence / distribution flow path 512. This can improve the heat exchange efficiency in the heat exchanger.

[0106] (Sixth embodiment) 10 is a plan view of an intermediate plate 614 of a first header 610 of a heat exchanger according to the sixth embodiment. Components common to the other embodiments are denoted by the same reference numerals and will not be described further. As shown in FIG. 10, the intermediate plate 614 has a plurality of spatial flow paths 16 (16A to 16H) and a confluence / distribution flow path 612.

[0107] The confluence distribution channel 612 has a plurality (two) of outlet channels 561, one confluence channel 62, and a plurality (two) of 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 branch channels 663 are referred to as a first branch channel 663A and a second branch channel 663B, respectively. The first branch channel 663A and the second branch channel 663B are channels formed by branching the confluence channel 62 into two.

[0108] The first branch channel 663A extends obliquely upward from the +Z direction end (tip) of the junction channel 62 as a base end, and reaches the first spatial channel 16A. The first branch channel 663A is inclined so as to rise in the -Y direction. The first branch channel 663A can guide the refrigerant to the first spatial channel 16A (the spatial channel to which the refrigerant is distributed).

[0109] The second branch channel 663B extends obliquely downward from the +Z direction end (tip) of the junction channel 62 as a base end, and reaches the sixth spatial channel 16F. The second branch channel 663B is inclined downward as it goes in the +Y direction. The second branch channel 663B can guide the refrigerant to the sixth spatial channel 16F (distribution destination spatial channel).

[0110] The first branch flow path 663A and the second branch flow path 663B have a cross-sectional area larger than that of the merging flow path 62. Therefore, when the refrigerant in the merging flow path 62 is distributed to the first branch flow path 663A and the second branch flow path 663B, it is opened into a flow path with a larger cross-sectional area and diffuses. This makes the refrigerant more likely to flow turbulently. This makes it possible to suppress drift in the refrigerant in a gas-liquid two-phase state.

[0111] 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 can be mixed and redistributed within the confluence / distribution flow path 612. This can improve the heat exchange efficiency in the heat exchanger.

[0112] (Seventh embodiment) 11 is a plan view of an intermediate plate 714 of a first header 710 of a heat exchanger according to the seventh embodiment. Components common to other embodiments are denoted by the same reference numerals and will not be described further. As shown in FIG. 11, the intermediate plate 714 has a plurality of spatial flow paths 16 (16A to 16H) and a confluence / distribution flow path 712.

[0113] The confluence / distribution channel 712 has a plurality (two) of outlet channels 561, one confluence channel 62, and a plurality (two) of branch channels 763. The confluence channel 62 extends straight in the +Z direction, which is opposite to the direction of gravity, from a base end where the tips of the first outlet channel 561A and the second outlet channel 561B are connected. The two branch channels 763 are referred to as a first branch channel 763A and a second branch channel 763B, respectively.

[0114] The first branch flow path 763A is L-shaped. The first branch flow path 763A extends in the -Y direction with the +Z direction end (tip) of the junction flow path 62 as its base end, changes direction to the +Z direction at its tip, and changes direction to the -Y direction again at its tip. The first branch flow path 763A reaches the first spatial flow path 16A. The first branch flow path 763A can guide the refrigerant to the first spatial flow path 16A (the spatial flow path to which the refrigerant is distributed).

[0115] The second branch flow path 763B is L-shaped. The second branch flow path 763B extends in the +Y direction from the +Z direction end (tip) of the junction flow path 62 as its base end, and changes direction to the -Z direction at the tip. The second branch flow path 763B reaches the sixth spatial flow path 16F. The second branch flow path 763B can guide the refrigerant to the sixth spatial flow path 16F (spatial flow path to which the refrigerant is distributed).

[0116] The portion including the base ends of the branch flow paths 763A and 763B is a direction changer 715. The direction changer 715 changes the flow direction of the refrigerant from the merging flow path 62. The direction changer 715 is formed along the Y direction. The direction changer 715 has an inner diameter D in the Y direction at the end (tip) of the merging flow path 62 in the +Z direction. 62 The direction in which the direction change portion 715 is formed is perpendicular to the extending direction (Z direction) of the end (tip) of the junction flow path 62 in the +Z direction. The configuration of the branch flow paths 763A and 763B other than the direction change portion 715 is similar to that of the branch flow paths 563A and 563B shown in FIG.

[0117] The refrigerant in the confluence flow path 62 moves in the direction opposite to the direction of gravity (the direction of the arrow shown in Figure 11), collides with the upper surface of the direction change section 715, and is distributed to the first spatial flow path 16A and the sixth spatial flow path 16F by the two branch flow paths 763.

[0118] In this heat exchanger, because direction changer 715 is perpendicular to junction flow path 62, the flow of refrigerant can be directed evenly into two branch flow paths 763. Therefore, the refrigerant can be evenly distributed to first branch flow path 763A and second branch flow path 763B. Therefore, it is possible to reduce the unevenness in the amount of refrigerant flowing into first branch flow path 763A and second branch flow path 763B.

[0119] The direction changer 715 has an inner diameter D in the Y direction at the end (tip) in the +Z direction of the merging flow path 62. 62 Because of its longer length, the refrigerant in the confluence flow path 62 hits the upper surface of the direction change portion 715, which has a sufficient length. This allows the flow of the refrigerant to be evenly distributed to the two branch flow paths 763.

[0120] (Eighth embodiment) 12 is a plan view of an intermediate plate 814 of a first header 810 of a heat exchanger according to the eighth embodiment. Components common to other embodiments are denoted by the same reference numerals and will not be described further. As shown in FIG. 12, the intermediate plate 814 has a plurality of spatial flow paths 16 (16A to 16H) and a confluence / distribution flow path 812.

[0121] The confluence / distribution channel 812 has a plurality of (two) outlet channels 561, one confluence channel 62, and a plurality of (two) branch channels 863. The confluence channel 62 extends straight in the +Z direction, which is opposite to the direction of gravity, from a base end where the tips of the first outlet channel 561A and the second outlet channel 561B are connected. The two branch channels 863 are referred to as a first branch channel 863A and a second branch channel 863B, respectively.

[0122] The first branch flow path 863A extends in the -Y direction from the +Z direction end (tip) of the merging flow path 62 as a base end, extends obliquely upward at its tip, and reaches the first spatial flow path 16 A. The second branch flow path 863B extends in the +Y direction from the +Z direction end (tip) of the merging flow path 62 as a base end, extends obliquely downward at its tip, and reaches the sixth spatial flow path 16 F.

[0123] The portion including the base ends of the branch flow paths 863A and 863B is a direction changer 815. The direction changer 815 changes the flow direction of the refrigerant from the merging flow path 62. The direction changer 815 is formed along the Y direction. The direction changer 815 has an inner diameter D in the Y direction at the end (tip) of the merging flow path 62 in the +Z direction. 62 The direction in which the direction change portion 815 is formed is perpendicular to the extending direction (Z direction) of the end (tip) of the junction flow path 62 in the +Z direction. The configuration of the branch flow paths 863A and 863B other than the direction change portion 815 is similar to that of the branch flow paths 663A and 663B shown in FIG.

[0124] In this heat exchanger, since the direction changer 815 is perpendicular to the junction flow path 62, the flow direction of the refrigerant can be directed equally to the first branch flow path 863A and the second branch flow path 863B. Therefore, it is possible to reduce the imbalance in the amount of refrigerant flowing into the first branch flow path 863A and the second branch flow path 863B.

[0125] The direction changer 815 has an inner diameter D in the Y direction at the end (tip) in the +Z direction of the merging flow path 62. 62 Because it is longer, the refrigerant in the converging flow path 62 hits the upper surface of the direction changing portion 815, which has a sufficient length. This allows the flow of the refrigerant to be evenly distributed to the two branching flow paths 863.

[0126] (Ninth embodiment) Fig. 13 is a plan view of an intermediate plate 914 of a first header 910 of a heat exchanger according to the ninth embodiment. Components common to other embodiments are denoted by the same reference numerals and will not be described further. 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 in the intermediate plate 914.

[0127] The gap 920 is linear and passes between the branch flow path 63 and the spatial flow path 16 that is closest to the branch flow path 63. The gap 920 is formed by a through-hole that passes 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.

[0128] At least a portion of the first gap 920A is formed between the first branch flow path 63A and the third spatial flow path 16C. For example, the first gap 920A is formed parallel to the first branch flow path 63A. At least a portion of the second gap 920B is formed between the second branch flow path 63B and the fourth spatial flow path 16D. For example, the second gap 920B is formed parallel to the second branch flow path 63B.

[0129] In this heat exchanger, thermal interference from the spatial channels 16C and 16D can be suppressed by the gap 920. Therefore, the deviation in the flow rate of the refrigerant caused by the phase change of the refrigerant in the branch channel 63 can be reduced.

[0130] (Comparative form) Fig. 14 is a plan view of an intermediate plate 1014 of a first header 1010 of a heat exchanger of a comparative example. Fig. 15 is an enlarged plan view of the intermediate plate 1014. As shown in FIG. 14, the intermediate plate 1014 has a plurality of spatial channels 16 (16A to 16H) and a distribution channel 1012. 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 extending in the Y direction and a second partial channel 1061B extending in the Z direction. The outlet channel 1061 is L-shaped. The first partial channel 1061A is shorter than the pitch of the heat exchanger tubes 30 (see P1 in FIG. 7). 15, in this heat exchanger, the liquid phase M1 and the gas phase M2 of the refrigerant may become unbalanced at the bend in the L-shaped outlet flow path 1061. Because the first partial flow path 1061A is short, the liquid phase M1 and the gas phase M2 tend to be insufficiently mixed. As a result, the unbalanced liquid phase M1 and the gas phase M2 may be maintained, and the amount of the refrigerant distributed to the two branch flow paths 1063 may become unbalanced.

[0131] According to at least one of the embodiments described above, the header has a confluence / distribution flow path. The confluence / distribution flow path confluences refrigerant from multiple heat exchange tubes and distributes it to multiple other heat exchange tubes. In the heat exchanger of the embodiment, the refrigerant flowing through the multiple heat exchange tubes can be mixed and redistributed within the confluence / distribution flow path. Although differences in thermal load may occur between multiple heat exchange tubes, the heat exchanger of the embodiment can mix and redistribute the refrigerant, thereby reducing the differences in thermal load. Therefore, it is possible to prevent a decrease in heat exchange efficiency due to differences in thermal load. Therefore, it is possible to improve the heat exchange efficiency of the heat exchanger.

[0132] Although several embodiments of the present 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, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, as well as the inventions described in the claims and their equivalents. [Explanation of symbols]

[0133] 1 Refrigeration cycle device 4 Outdoor heat exchanger (heat exchanger) 10 First Header (Header) 12,512,612,712,812 Confluence and distribution channels 16 Spatial flow path 30 Heat exchange tubes 34 refrigerant flow path 62 Confluence 63,563,663,763,863 Branching 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 flow path (confluence and distribution flow path) 218,318 Narrow area 615,715,815 Direction change section 920 Cavity L1 Length of the confluence channel P1 Heat exchange tube pitch

Claims

1. a plurality of heat exchange tubes each having a refrigerant flow path formed therein through which a refrigerant flows; a header provided at an end of the heat exchange tube; Equipped with At least one of the headers includes: a plurality of spatial flow paths communicating with the heat exchange tubes; a confluence flow path through which the refrigerant flows, the refrigerant being converged from two or more of the spatial flow paths; a plurality of branch flow paths branched from the confluent flow path, the plurality of branch flow paths communicate with the plurality of spatial flow paths; The joining flow path is formed along the vertical direction, the branch flow path extends obliquely downward from a tip of the merging flow path toward the spatial flow path, heat exchanger.

2. At least some of the heat exchange tubes are arranged in multiple stages, The length of the confluence flow path is longer than the pitch of the heat exchange tubes arranged in multiple stages. The heat exchanger of claim 1 .

3. a portion including a base end of the branch flow path is a direction changing portion that changes the flow direction of the refrigerant from the merging flow path, the direction change portion is perpendicular to the extending direction of the tip of the merging flow path, The length of the direction change portion is longer than the inner diameter of the tip of the merging flow path.

3. The heat exchanger according to claim 1 or 2.

4. The deviation (absolute value) of the following Fp of the plurality of branch flow paths is 20% or less: The heat exchanger according to any one of claims 1 to 3. [Equation 1] (L represents the length [m] of the branch flow path. G represents the mass flux [kg / s / m ２ D indicates the hydraulic equivalent diameter [m] of the branch flow path.)

5. a gap is formed between the branch flow path and the spatial flow path of the header; A heat exchanger according to any one of claims 1 to 4.

6. A refrigeration cycle device comprising the heat exchanger according to any one of claims 1 to 5.

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