Heat exchanger, outdoor unit, and refrigeration cycle device

Abstract

The present invention provides a heat exchanger, an outdoor unit, and a refrigeration cycle device. The heat exchanger includes flat tubes, a header, and a refrigerant inlet. The header includes a first plate-shaped member, a second plate-shaped member, and a third plate-shaped member. The first plate-shaped member has a bulged portion forming a reservoir space. The second plate-shaped member has a first flow path and a second flow path. The first flow path extends so as to overlap with the reservoir space, and the second flow path extends so as not to overlap with the reservoir space. The upper portion of the first flow path is connected to the upper portion of the second flow path via a first connecting flow path, and the lower portion of the first flow path is connected to the lower portion of the second flow path via a second connecting flow path. The third plate-shaped member has a communication hole that connects the first flow path to the flat tubes.

Description

[0001] This invention patent application is a divisional application of the invention patent application with international application number PCT / JP2018 / 040101 (Chinese application number 201880098690.5), application date October 29, 2018, and invention name “Heat exchanger and refrigeration cycle device”. Technical Field

[0002] The present invention relates to a heat exchanger and a refrigeration cycle device including a plurality of flat tubes and a header. Background Art

[0003] Patent Document 1 describes a heat exchanger comprising: a plurality of horizontally extending flat tubes arranged vertically; and a pair of vertically extending header tanks connected to both ends of each flat tube. The header tanks consist of a connecting plate with elongated holes for inserting and connecting the flat tubes; a connecting plate with connecting holes corresponding to the elongated holes in the connecting plate; and a tank plate with a semi-cylindrical refrigerant passage.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Laid-Open No. 2004-69228 Summary of the Invention

[0007] Problems to be solved by the invention

[0008] When the heat exchanger described in Patent Document 1 functions as a refrigerant evaporator, a two-phase gas-liquid refrigerant flows into a header tank located on the inlet side of the heat exchanger. If the refrigerant inlet is located at the lower portion of the header tank, the gas-liquid refrigerant flowing into the header tank flows upward within the header tank and is distributed to the flat tubes. However, in this case, the liquid refrigerant, which has a higher density than the gas refrigerant, is retained in the upper portion of the header tank due to inertia. Therefore, the amount of refrigerant distributed to the flat tubes located further up the stack increases. This leads to variations in the amount of refrigerant distributed to each flat tube.

[0009] The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a heat exchanger and a refrigeration cycle device capable of distributing refrigerant more evenly to a plurality of flat tubes.

[0010] Solutions to Problems

[0011] The present invention relates to a heat exchanger, wherein the heat exchanger comprises: a plurality of flat tubes, which are arranged side by side in the vertical direction and allow refrigerant to circulate; a header, which extends in the vertical direction and is connected to one end of each of the plurality of flat tubes; and a refrigerant inlet, which is formed at the lower part of the header, the header comprising: a first plate-shaped member; a second plate-shaped member, which is arranged between the first plate-shaped member and the plurality of flat tubes; and a third plate-shaped member, which is arranged between the second plate-shaped member and the plurality of flat tubes, the first plate-shaped member having a bulging portion, which forms a storage tank space extending in the vertical direction and communicating with the refrigerant inlet, the second plate-shaped member having a first flow path and a second flow path, the first flow path being at a thickness of the second plate-shaped member. The 3rd plate-shaped member is provided with a first connecting channel and a second connecting channel, and the 3rd plate-shaped member is provided with a second connecting channel, the 3rd plate-shaped member is provided with a second connecting channel, and the 3rd plate-shaped member is provided with a second connecting channel.

[0012] A refrigeration cycle device according to the present invention includes the heat exchanger according to the present invention.

[0013] Effects of the Invention

[0014] According to the present invention, liquid refrigerant that reaches the upper portion of the first flow path without being distributed to any of the plurality of flat tubes within the gas-liquid two-phase refrigerant flowing through the first flow path passes through the first connecting flow path, the second flow path, and the second connecting flow path before returning to the lower portion of the first flow path. This prevents accumulation of liquid refrigerant in the upper portion of the first flow path. Consequently, according to the present invention, refrigerant can be distributed more evenly across the plurality of flat tubes. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is an exploded perspective view showing the configuration of a main part of the heat exchanger according to Embodiment 1 of the present invention.

[0016] Figure 2 This is a cross-sectional view showing the structure of the flat tube 70 of the heat exchanger according to Embodiment 1 of the present invention.

[0017] Figure 3 It is a cross-sectional view showing the structure of a header 60 of the heat exchanger according to Embodiment 1 of the present invention.

[0018] Figure 4 This is an exploded perspective view showing the configuration of a main part of a heat exchanger according to Embodiment 2 of the present invention.

[0019] Figure 5 It is a cross-sectional view showing the structure of a header 60 of a heat exchanger according to Embodiment 2 of the present invention.

[0020] Figure 6 This is an exploded perspective view showing the configuration of a main part of a heat exchanger according to Embodiment 3 of the present invention.

[0021] Figure 7 It is a cross-sectional view showing the structure of a header 60 of a heat exchanger according to Embodiment 3 of the present invention.

[0022] Figure 8 It is an exploded perspective view showing the main structure of a heat exchanger according to Embodiment 4 of the present invention.

[0023] Figure 9 This is a refrigerant circuit diagram showing the configuration of a refrigeration cycle device according to Embodiment 5 of the present invention.

[0024] Figure 10 This is a refrigerant circuit diagram showing the configuration of a refrigeration cycle device according to a modified example of Embodiment 5 of the present invention. DETAILED DESCRIPTION

[0025] Implementation method 1.

[0026] The heat exchanger according to Embodiment 1 of the present invention will be described. Figure 1 It is an exploded perspective view showing the main structure of the heat exchanger according to this embodiment. Figure 1 The up and down directions represent the vertical up and down directions. The heat exchanger involved in this embodiment is an air heat exchanger that performs heat exchange between air and refrigerant, and functions as at least an evaporator of a refrigeration cycle device. Figure 1 In the following drawings, the direction of air flow is indicated by a blank arrow. In the specification, the positional relationship between the components, the extending direction of the components, and the parallel direction of the components are, in principle, elements for setting the heat exchanger in a usable state.

[0027] like Figure 1As shown, the heat exchanger includes: a plurality of flat tubes 70 through which refrigerant circulates; a header 60 connected to one end of each of the flat tubes 70; and a refrigerant inlet 15 formed in the lower portion of the header 60. The flat tubes 70 extend horizontally. The flat tubes 70 are vertically aligned. The header 60 extends vertically along the alignment of the flat tubes 70. A gap 71, which serves as a flow path for air, is formed between two adjacent flat tubes 70. Heat transfer fins may also be provided between adjacent flat tubes 70. Although not shown, a cylindrical header, for example, is connected to the other end of each of the flat tubes 70. When the heat exchanger functions as an evaporator in a refrigeration cycle device, refrigerant flows from one end to the other end of each of the flat tubes 70. When the heat exchanger functions as a condenser of a refrigeration cycle device, in each of the plurality of flat tubes 70 , the refrigerant flows from the other end to the one end.

[0028] Figure 2 : is a cross-sectional view showing the structure of the flat tube 70 of the heat exchanger according to this embodiment. Figure 2 , a cross section perpendicular to the extending direction of the flat tube 70 is shown. Figure 2 As shown in FIG. 1 , the flat tube 70 has a cross-sectional shape that is flat in one direction, such as an oblong shape. The flat tube 70 has a first side end 70a, a second side end 70b, and a pair of flat surfaces 70c and 70d. Figure 2 In the cross section shown, the first side end portion 70a is connected to one end portion of the flat surface 70c and one end portion of the flat surface 70d. In this cross section, the second side end portion 70b is connected to the other end portion of the flat surface 70c and the other end portion of the flat surface 70d. The first side end portion 70a is a side end portion that is arranged on the upwind side, i.e., the leading edge side, in the flow of air passing through the heat exchanger. The second side end portion 70b is a side end portion that is arranged on the leeward side, i.e., the trailing edge side, in the flow of air passing through the heat exchanger. Hereinafter, the direction perpendicular to the extension direction of the flat tube 70 and along the flat surfaces 70c, 70d is sometimes referred to as the major diameter direction of the flat tube 70. Figure 2 In FIG, the long-axis direction of the flat tube 70 is the left-right direction. The long-axis dimension of the flat tube 70 in the long-axis direction is L1.

[0029] The flat tube 70 has a plurality of refrigerant passages 72 arranged along the major diameter between the first end portion 70a and the second end portion 70b. In other words, the flat tube 70 is a flat multi-hole tube having a plurality of refrigerant passages 72. Each of the plurality of refrigerant passages 72 is formed to extend parallel to the direction in which the flat tube 70 extends.

[0030] return Figure 1The header 60 includes a first plate-shaped member 10, a second plate-shaped member 20, a third plate-shaped member 30, a fourth plate-shaped member 40, and a fifth plate-shaped member 50. Each of the first plate-shaped member 10, the second plate-shaped member 20, the third plate-shaped member 30, the fourth plate-shaped member 40, and the fifth plate-shaped member 50 is formed from flat metal plates and has a strip-like shape extending in one direction. The outer edges of the first plate-shaped member 10, the second plate-shaped member 20, the third plate-shaped member 30, the fourth plate-shaped member 40, and the fifth plate-shaped member 50 have the same contour. The first plate-shaped member 10, the second plate-shaped member 20, the third plate-shaped member 30, the fourth plate-shaped member 40, and the fifth plate-shaped member 50 are arranged so that their respective plate thickness directions are parallel to the direction in which the flat tubes 70 extend, that is, their respective plate surfaces are perpendicular to the direction in which the flat tubes 70 extend.

[0031] The header 60 has a structure in which the first plate-shaped member 10, the second plate-shaped member 20, the third plate-shaped member 30, the fifth plate-shaped member 50, and the fourth plate-shaped member 40 are stacked in order from the position furthest from the flat tubes 70. The first plate-shaped member 10 is furthest from the flat tubes 70, while the fourth plate-shaped member 40, not the fifth plate-shaped member 50, is closest to the flat tubes 70. The second plate-shaped member 20 is positioned between the first plate-shaped member 10 and the flat tubes 70, adjacent to the first plate-shaped member 10. The third plate-shaped member 30 is positioned between the second plate-shaped member 20 and the flat tubes 70, adjacent to the second plate-shaped member 20. The fifth plate-shaped member 50 is positioned between the third plate-shaped member 30 and the flat tubes 70, adjacent to the third plate-shaped member 30. The fourth plate-shaped member 40 is positioned between the fifth plate-shaped member 50 and the flat tubes 70, adjacent to the fifth plate-shaped member 50. One end of each of the plurality of flat tubes 70 is connected to the fourth plate-shaped member 40. Adjacent members among the first plate-shaped member 10, the second plate-shaped member 20, the third plate-shaped member 30, the fifth plate-shaped member 50, and the fourth plate-shaped member 40 are joined by brazing. The first plate-shaped member 10, the second plate-shaped member 20, the third plate-shaped member 30, the fifth plate-shaped member 50, and the fourth plate-shaped member 40 are arranged so that their longitudinal directions extend in the vertical direction.

[0032] Figure 3 : is a cross-sectional view showing the structure of the header 60 of the heat exchanger according to this embodiment. Figure 3 , a cross section parallel to the extending direction and the major diameter direction of the flat tube 70 is shown. The thickness direction of each of the first plate-shaped member 10, the second plate-shaped member 20, the third plate-shaped member 30, the fifth plate-shaped member 50, and the fourth plate-shaped member 40 is Figure 3 The short side direction of each of the first plate-shaped member 10, the second plate-shaped member 20, the third plate-shaped member 30, the fifth plate-shaped member 50 and the fourth plate-shaped member 40 is Figure 3 Up and down direction.

[0033] As Figure 1 and Figure 3 shown, the first plate-like member 10 has a bulging portion 11 that bulges in a direction away from the flat tube 70. The bulging portion 11 extends from one end in the longitudinal direction of the first plate-like member 10 to the other end in the longitudinal direction along the longitudinal direction of the first plate-like member 10. The bulging portion 11 has a cross-sectional shape of a semi-circular shape, a semi-elliptical shape, or a semi-oval shape. The bulging portion 11 is formed at the center portion in the short side direction of the first plate-like member 10. In addition, the first plate-like member 10 has a pair of flat portions 12a and 12b formed in a flat plate shape on both sides of the bulging portion 11. Both the flat portions 12a and 12b extend from one end in the longitudinal direction of the first plate-like member 10 to the other end in the longitudinal direction along the longitudinal direction of the first plate-like member 10.

[0034] Inside the bulging portion 11, a storage space 13 extending in the vertical direction along the longitudinal direction of the first plate-like member 10 is formed. The storage space 13 has a cross-sectional shape of a semi-circular shape, a semi-elliptical shape, or a semi-oval shape. That is, the storage space 13 is a space formed in a semi-cylindrical shape, a semi-elliptical cylindrical shape, or a semi-oval cylindrical shape. The storage space 13 communicates with the refrigerant inlet 15. The width direction of the storage space 13 is parallel to the short side direction of the first plate-like member 10. The width dimension W1 of the storage space 13 in the width direction is smaller than the major diameter dimension L1 of the flat tube 70 (W1 < L1). By setting the shape of the storage space 13 to a semi-cylindrical shape, a semi-elliptical cylindrical shape, or a semi-oval cylindrical shape, the internal volume of the storage space 13 can be reduced compared to a cylindrical storage space. In addition, by setting the width dimension W1 of the storage space 13 to be smaller than the major diameter dimension L1 of the flat tube 70, the internal volume of the storage space 13 can be further reduced. Therefore, for a refrigeration cycle device equipped with the heat exchanger of the present embodiment, the amount of refrigerant can be reduced.

[0035] When viewed in the plate thickness direction of the first plate-like member 10, the storage space 13 extends crossing the plurality of flat tubes 70 respectively. In addition, when viewed in the plate thickness direction of the first plate-like member 10, the center portion in the width direction of the storage space 13 overlaps with the center portion in the major diameter direction of each flat tube 70. The upper end portion of the storage space 13 is closed by a closing member 14. A refrigerant inlet 15 is provided at the lower end portion of the storage space 13. The refrigerant inlet 15 is configured to allow the gas-liquid two-phase refrigerant to flow upward into the storage space 13 when the heat exchanger functions as an evaporator. In addition, when the heat exchanger functions as a condenser, the liquid refrigerant in the storage space 13 flows downward through the refrigerant inlet 15.

[0036] The second plate-shaped member 20 has a first flow path 21 and a second flow path 22. The first flow path 21 penetrates the second plate-shaped member 20 in the plate thickness direction of the second plate-shaped member 20 and extends in the vertical direction along the longitudinal direction of the second plate-shaped member 20. The upper end of the first flow path 21 does not reach the upper end of the second plate-shaped member 20 and is closed by an upper frame portion 26 that is part of the second plate-shaped member 20. The lower end of the first flow path 21 does not reach the lower end of the second plate-shaped member 20 and is closed by a lower frame portion 27 that is part of the second plate-shaped member 20. The first flow path 21 is configured so as to overlap with the storage tank space 13 when viewed in the plate thickness direction of the second plate-shaped member 20. The first flow path 21 may also be configured so that the entire first flow path 21 overlaps with the storage tank space 13 when viewed in the plate thickness direction of the second plate-shaped member 20. In addition, the width dimension of the first flow path 21 may be the same as the width dimension W1 of the storage tank space 13. The first flow path 21, together with the storage space 13, functions as an ascending flow path for upwardly circulating the gas-liquid two-phase refrigerant flowing in from the refrigerant inlet 15. When viewed along the thickness direction of the second plate-shaped member 20, the widthwise center of the first flow path 21 overlaps with the longitudinal center of each flat tube 70.

[0037] The second flow path 22 penetrates the second plate-like member 20 in the plate thickness direction of the second plate-like member 20 and extends in the up-down direction along the first flow path 21. The upper end of the second flow path 22 does not reach the upper end of the second plate-like member 20 and is closed by the upper frame portion 26. The lower end of the second flow path 22 does not reach the lower end of the second plate-like member 20 and is closed by the lower frame portion 27. The second flow path 22 is configured so as not to overlap with the storage tank space 13 when viewed in the plate thickness direction of the second plate-like member 20. The flow path width of the second flow path 22 in the short side direction of the second plate-like member 20 is the same as or smaller than the flow path width of the first flow path 21 in this direction. The second flow path 22 functions as a descending flow path for causing the liquid refrigerant to flow downward. In Figure 1 as well as Figure 3 In the illustrated header 60 , the second flow passage 22 is arranged on the leeward side of the first flow passage 21 , but the second flow passage 22 may be arranged on the upwind side of the first flow passage 21 .

[0038] The first flow path 21 and the second flow path 22 are separated by a partition member 25 extending in the vertical direction. The partition member 25 is formed as a separate member from the second plate-shaped member 20 using a metal flat plate having the same thickness as the second plate-shaped member 20. The partition member 25 may also be formed integrally with the first plate-shaped member 10 or the third plate-shaped member 30, which is a member adjacent to the second plate-shaped member 20.

[0039] The second plate-shaped member 20 also includes a first connecting flow path 23 formed between the upper end of the partition member 25 and the upper frame portion 26, and a second connecting flow path 24 formed between the lower end of the partition member 25 and the lower frame portion 27. Both the first connecting flow path 23 and the second connecting flow path 24 penetrate the second plate-shaped member 20 in the thickness direction and extend along the short side of the second plate-shaped member 20. The first connecting flow path 23 connects the upper portion of the first flow path 21 with the upper portion of the second flow path 22. When viewed in the thickness direction of the second plate-shaped member 20, the first connecting flow path 23 is located above the topmost flat tube 70 among the plurality of flat tubes 70. The second connecting flow path 24 is formed below the first connecting flow path 23 and connects the lower portion of the first flow path 21 with the lower portion of the second flow path 22. When viewed in the thickness direction of the second plate-shaped member 20 , the second connecting flow path 24 is located below the lowermost flat tube 70 among the plurality of flat tubes 70 . Figure 1 The width of the first connecting flow path 23 in the vertical direction is equal to or greater than the width of the second connecting flow path 24 in the same direction. The first connecting flow path 23 and the second connecting flow path 24, together with the first flow path 21 and the second flow path 22, constitute a circulation flow path through which the refrigerant circulates. Thus, refrigerant that rises in the first flow path 21 or the storage tank space 13 and reaches the upper end of the first flow path 21 returns to the lower portion of the first flow path 21 via the first connecting flow path 23, the second flow path 22, and the second connecting flow path 24.

[0040] At least one of the first connecting flow path 23 and the second connecting flow path 24 may be formed in the third plate-shaped member 30. In this case, since the partition member 25 and the second plate-shaped member 20 can be integrated, the number of components of the header 60 can be reduced. In other words, the first connecting flow path 23 and the second connecting flow path 24 are formed in the second plate-shaped member 20 or the third plate-shaped member 30, respectively.

[0041] The third plate-shaped member 30 has a single communicating hole 31. The communicating hole 31 penetrates the third plate-shaped member 30 in the thickness direction of the third plate-shaped member 30 and extends in the vertical direction along the length of the third plate-shaped member 30. The upper end of the communicating hole 31 does not reach the upper end of the third plate-shaped member 30 and is closed by an upper frame portion 32, which is part of the third plate-shaped member 30. The lower end of the communicating hole 31 does not reach the lower end of the third plate-shaped member 30 and is closed by a lower frame portion 33, which is part of the third plate-shaped member 30. The communicating hole 31 is arranged so as to overlap with the first flow path 21 of the second plate-shaped member 20 when viewed in the thickness direction of the third plate-shaped member 30. The communicating hole 31 may also be arranged so that the entire communicating hole 31 overlaps with the first flow path 21 when viewed in the thickness direction of the third plate-shaped member 30. Alternatively, the width dimension of the communicating hole 31 may be the same as the width dimension of the first flow path 21. When viewed along the thickness direction of the third plate-shaped member 30, the widthwise center of the communication hole 31 overlaps the longitudinal center of each flat tube 70. The first flow path 21 of the second plate-shaped member 20 communicates with the plurality of flat tubes 70 via the communication hole 31.

[0042] The third plate-shaped member 30 also includes a flat-plate-shaped closing portion 34. The closing portion 34 corresponds to the portion of the third plate-shaped member 30 that overlaps with the second flow path 22 of the second plate-shaped member 20 when viewed along the thickness direction of the third plate-shaped member 30. The closing portion 34 closes off the gap between the second flow path 22 and each of the plurality of flat tubes 70. The closing portion 34 prevents the plurality of flat tubes 70 from directly communicating with the second flow path 22 without passing through the first flow path 21.

[0043] The fourth plate-shaped member 40 has a plurality of insertion holes 41 into which one end of each of the plurality of flat tubes 70 is inserted. Each of the plurality of insertion holes 41 extends through the fourth plate-shaped member 40 in the thickness direction of the fourth plate-shaped member 40. The plurality of insertion holes 41 are arranged vertically along the length of the fourth plate-shaped member 40. The insertion holes 41 have an opening shape that is flat, similar to the outer circumference of the flat tubes 70. The open ends of the insertion holes 41 are brazed to the outer circumference of the flat tubes 70 over their entire circumference.

[0044] The fifth plate-shaped member 50, positioned between the third plate-shaped member 30 and the fourth plate-shaped member 40, has a plurality of through-holes 51. Each through-hole 51 extends through the fifth plate-shaped member 50 in the thickness direction. The through-holes 51 are independently provided corresponding to the plurality of flat tubes 70. The through-holes 51 are arranged vertically along the length of the fifth plate-shaped member 50. The through-holes 51 have an opening shape that is flat, similar to the outer circumference of the flat tubes 70. The opening area of ​​each through-hole 51 is equal to or larger than the opening area of ​​each insertion hole 41 of the fourth plate-shaped member 40. When viewed along the extension direction of the flat tubes 70, the opening ends of the through-holes 51 overlap with or are located outside the outer circumference of the flat tubes 70. Within each through-hole 51, an insertion space 52 corresponding to each flat tube 70 is formed. One end of the flat tube 70 passes through the insertion hole 41 of the fourth plate-shaped member 40 and reaches the insertion space 52. The open ends of the multiple refrigerant passages 72 formed at one end of the flat tube 70 all face the insertion space 52. The multiple refrigerant passages 72 of the flat tube 70 communicate with the first flow path 21 and the tank space 13 via the insertion space 52 and the communication hole 31, respectively. Here, in the case where the flat tube 70 does not pass through the insertion hole 41 of the fourth plate-shaped member 40 and one end of the flat tube 70 is located midway in the insertion hole 41, the insertion space facing the open ends of the multiple refrigerant passages 72 is formed within the insertion hole 41. In this case, the fifth plate-shaped member 50 can be omitted from the configuration of the header 60.

[0045] Next, the operation of the heat exchanger according to this embodiment will be described, using as an example the operation of the heat exchanger functioning as an evaporator of a refrigeration cycle device. A gas-liquid two-phase refrigerant, decompressed by a decompression device, flows into the heat exchanger functioning as an evaporator. The gas-liquid two-phase refrigerant flowing into the heat exchanger first flows from the refrigerant inlet 15 into the storage space 13 of the header 60. The gas-liquid two-phase refrigerant flowing into the storage space 13 flows upward through the storage space 13 and the first flow path 21, which serve as an ascending flow path, and is distributed to the plurality of flat tubes 70 via the communication holes 31 and the respective insertion spaces 52.

[0046] At this time, a portion of the liquid refrigerant in the gas-liquid two-phase refrigerant circulating in the storage tank space 13 and the first flow path 21 reaches the upper end of the storage tank space 13 and the upper end of the first flow path 21 without being distributed to any of the multiple flat tubes 70 due to inertial force. The liquid refrigerant that has reached the upper end of the storage tank space 13 and the upper end of the first flow path 21 flows into the second flow path 22 through the first connecting flow path 23. The liquid refrigerant that has flowed into the second flow path 22 flows downward in the second flow path 22, passes through the second connecting flow path 24, and returns to the lower part of the first flow path 21. The liquid refrigerant that has returned to the lower part of the first flow path 21 merges with the gas-liquid two-phase refrigerant that has flowed into the storage tank space 13 from the refrigerant inlet 15, and again flows upward in the storage tank space 13 and the first flow path 21, being distributed to the multiple flat tubes 70.

[0047] The gas-liquid two-phase refrigerant distributed to the flat tubes 70 flows through any of the plurality of refrigerant passages 72, exchanges heat with the air, and evaporates into gas refrigerant. This gas refrigerant flows through a header pipe provided at the other end of the flat tubes 70 to the compressor side of the refrigerant circuit.

[0048] In this way, liquid refrigerant that reaches the upper end of the sump space 13 and the upper end of the first flow path 21 returns to the lower portion of the first flow path 21 via the first connecting flow path 23, the second flow path 22, and the second connecting flow path 24. Consequently, the amount of liquid refrigerant stagnating at the upper end of the sump space 13 and the upper end of the first flow path 21 is reduced. Consequently, the amount of refrigerant distributed toward the upper flat tubes 70 is reduced, allowing for more even distribution of refrigerant across the plurality of flat tubes 70.

[0049] As described above, the heat exchanger according to this embodiment includes: a plurality of flat tubes 70 arranged vertically side by side and through which refrigerant circulates; a header 60 extending vertically and connected to one end of each of the plurality of flat tubes 70; and a refrigerant inlet 15 formed in the lower portion of the header 60. The header 60 includes: a first plate-shaped member 10; a second plate-shaped member 20 disposed between the first plate-shaped member 10 and the plurality of flat tubes 70; and a third plate-shaped member 30 disposed between the second plate-shaped member 20 and the plurality of flat tubes 70. The first plate-shaped member 10 includes a bulged portion 11 that defines a vertically extending reservoir space 13 that communicates with the refrigerant inlet 15. The second plate-shaped member 20 includes a first flow path 21 and a second flow path 22. The first flow path 21 penetrates the second plate-shaped member 20 in the thickness direction of the second plate-shaped member 20. In addition, the first flow path 21 extends in the vertical direction so as to overlap with the storage tank space 13 when viewed along the plate thickness direction of the second plate-shaped member 20. The second flow path 22 penetrates the second plate-shaped member 20 in the plate thickness direction of the second plate-shaped member 20. In addition, the second flow path 22 extends in the vertical direction along the first flow path 21 so as not to overlap with the storage tank space 13 when viewed along the plate thickness direction of the second plate-shaped member 20. The upper portion of the first flow path 21 and the upper portion of the second flow path 22 are connected via the first connecting flow path 23. The lower portion of the first flow path 21 and the lower portion of the second flow path 22 are connected via the second connecting flow path 24 formed at a position lower than the first connecting flow path 23. The third plate-shaped member 30 has at least one connecting hole 31 that penetrates the third plate-shaped member 30 in the plate thickness direction of the third plate-shaped member 30 and connects the first flow path 21 with the plurality of flat tubes 70 respectively.

[0050] According to this configuration, the liquid refrigerant that reaches the upper portion of the first flow path 21 without being distributed to any of the plurality of flat tubes 70 among the gas-liquid two-phase refrigerant flowing upward in the first flow path 21 passes through the first connecting flow path 23, the second flow path 22, and the second connecting flow path 24 and returns to the lower portion of the first flow path 21. Thus, the liquid refrigerant is prevented from stagnating at the upper end portion of the first flow path 21. Therefore, according to the above configuration, the refrigerant can be distributed more evenly to the plurality of flat tubes 70. Thus, the heat exchanger performance of the heat exchanger can be improved. As a result, since the operating efficiency of the refrigeration cycle device equipped with the heat exchanger can be improved, energy saving of the refrigeration cycle device can be achieved.

[0051] Furthermore, in the above configuration, both the first flow path 21 and the second flow path 22 are formed in the second plate-shaped member 20. This allows the first flow path 21 and the second flow path 22 to be arranged in a planar shape, thereby preventing an increase in the thickness of the header 60 in the plate thickness direction. Consequently, the above configuration allows for a smaller heat exchanger and improved heat exchange performance.

[0052] Implementation method 2.

[0053] A heat exchanger according to Embodiment 2 of the present invention will be described. Figure 4 It is an exploded perspective view showing the main structure of the heat exchanger according to this embodiment. Figure 5 : is a cross-sectional view showing the structure of the header 60 of the heat exchanger according to this embodiment. Figure 5 In the figure, it is shown that Figure 3 Note that, components having the same functions and effects as those in the first embodiment are denoted by the same reference numerals and their descriptions are omitted.

[0054] like Figure 4 as well as Figure 5 As shown, in this embodiment, the bulged portion 11 of the first plate-shaped member 10 is formed at a position more upwind than the center portion in the short-side direction of the first plate-shaped member 10. Therefore, when viewed along the thickness direction of the first plate-shaped member 10, the center portion in the width direction of the storage tank space 13 is located more upwind than the center portion in the long-diameter direction of each flat tube 70.

[0055] The first flow passage 21 of the second plate-shaped member 20 and the communication hole 31 of the third plate-shaped member 30 are both arranged to overlap with the tank space 13. Therefore, when viewed along the thickness direction of the second plate-shaped member 20, the widthwise center of the first flow passage 21 is positioned upwind of the longitudinal center of each flat tube 70. Similarly, when viewed along the thickness direction of the third plate-shaped member 30, the widthwise center of the communication hole 31 is positioned upwind of the longitudinal center of each flat tube 70.

[0056] The heat transfer rate between the refrigerant and the air is highest in the flat tubes 70 at the first side end 70a, which is the upwind side and serves as the leading edge of the flat tubes 70. Therefore, by allowing a large amount of refrigerant to flow through the refrigerant passages 72 located closer to the first side end 70a, heat exchange between the refrigerant and the air is promoted, thereby improving the heat exchange efficiency when the heat exchanger functions as an evaporator.

[0057] As described above, in the heat exchanger according to this embodiment, the plurality of flat tubes 70 are flat multi-hole tubes each having a plurality of refrigerant passages 72 formed therein. The storage space 13 is formed on the upwind side relative to the center of each of the plurality of flat tubes 70 in the direction of the major diameter, as viewed along the thickness of the first plate-shaped member 10. This configuration allows a large amount of refrigerant to flow through the refrigerant passages 72 located on the upwind side of each of the plurality of flat tubes 70, thereby improving the heat exchanger performance of the heat exchanger. As a result, the operating efficiency of a refrigeration cycle device equipped with the heat exchanger can be improved, thereby achieving energy conservation in the refrigeration cycle device.

[0058] Implementation method 3.

[0059] A heat exchanger according to Embodiment 3 of the present invention will be described. Figure 6 It is an exploded perspective view showing the main structure of the heat exchanger according to this embodiment. Figure 7 : is a cross-sectional view showing the structure of the header 60 of the heat exchanger according to this embodiment. Figure 7 In the figure, it is shown that Figure 3 Note that, components having the same functions and effects as those in the first embodiment are denoted by the same reference numerals and their descriptions are omitted.

[0060] like Figure 6 as well as Figure 7 As shown, the third plate-shaped member 30 of this embodiment has a plurality of communicating holes 35 each having a circular opening shape. The plurality of communicating holes 35 are provided corresponding to each of the plurality of flat tubes 70. The plurality of communicating holes 35 penetrate the third plate-shaped member 30 in the plate thickness direction of the third plate-shaped member 30. The plurality of communicating holes 35 are arranged in the vertical direction along the longitudinal direction of the third plate-shaped member 30. The plurality of communicating holes 35 are arranged so as to overlap with the first flow path 21 of the second plate-shaped member 20 when viewed in the plate thickness direction of the third plate-shaped member 30. In addition, the plurality of communicating holes 35 are arranged so as to correspond to the plurality of insertion spaces 52 of the fifth plate-shaped member 50 when viewed in the plate thickness direction of the third plate-shaped member 30. Furthermore, the plurality of communicating holes 35 are arranged so as to overlap with the plurality of flat tubes 70 when viewed in the plate thickness direction of the third plate-shaped member 30.

[0061] The flow path cross-sectional area of ​​each of the plurality of communication holes 35 is smaller than the flow path cross-sectional area of ​​each of the plurality of flat tubes 70, that is, the sum of the flow path cross-sectional areas of the plurality of refrigerant passages 72 formed in each flat tube 70. Furthermore, the flow path cross-sectional area of ​​each of the plurality of communication holes 35 is smaller than the opening area of ​​each of the plurality of through holes 51.

[0062] The multiple communication holes 35 each function as a throttle hole with high flow resistance in the refrigerant flow path between the first flow path 21 and each of the multiple flat tubes 70. When the heat exchanger functions as an evaporator, each communication hole 35 functions as a throttle hole, thereby increasing the pressure in the reservoir space 13 and the first flow path 21. This increases the pressure difference between the reservoir space 13 and the first flow path 21 and the pressure in each of the multiple insertion spaces 52. Consequently, the pressure difference between the reservoir space 13 and the first flow path 21 and the pressure in the upper insertion spaces 52, and the pressure difference between the reservoir space 13 and the first flow path 21 and the pressure in the lower insertion spaces 52, become more uniform. As a result, the refrigerant in the reservoir space 13 and the first flow path 21 is evenly distributed to each insertion space 52 and, as a result, to each of the flat tubes 70.

[0063] As described above, in the heat exchanger according to this embodiment, at least one communicating hole includes a plurality of communicating holes 35. The flow path cross-sectional area of ​​each of the plurality of communicating holes 35 is smaller than the flow path cross-sectional area of ​​each of the plurality of flat tubes 70. This configuration increases the pressure in the reservoir space 13 and the first flow path 21, thereby evenly distributing the refrigerant to the plurality of flat tubes 70. This improves the heat exchanger performance of the heat exchanger. Consequently, the operating efficiency of a refrigeration cycle device equipped with the heat exchanger can be improved, thereby achieving energy conservation in the refrigeration cycle device.

[0064] Implementation method 4.

[0065] A heat exchanger according to a fourth embodiment of the present invention will be described. Figure 8 1 is an exploded perspective view showing the main structure of the heat exchanger according to the present embodiment. Components having the same functions and effects as those in any of Embodiments 1 to 3 are denoted by the same reference numerals and their descriptions are omitted.

[0066] like Figure 8 As shown, the first plate-shaped member 10 of the present embodiment has a bulging portion 11 formed at a position slightly upwind, similarly to the second embodiment. As a result, the center portion of the width direction of the storage tank space 13 is arranged at a position slightly upwind than the center portion of the long diameter direction of each flat tube 70 when viewed along the plate thickness direction of the first plate-shaped member 10. In addition, in the third plate-shaped member 30 of the present embodiment, a plurality of connecting holes 35 each having a circular opening shape are formed, similarly to the third embodiment. The plurality of connecting holes 35 are formed at a position slightly upwind of the third plate-shaped member 30 in such a manner as to overlap with the storage tank space 13 and the first flow path 21 when viewed along the plate thickness direction of the third plate-shaped member 30. The flow path cross-sectional area of ​​each of the plurality of connecting holes 35 is smaller than the flow path cross-sectional area of ​​each of the plurality of flat tubes 70.

[0067] This embodiment has a structure that combines the structures of Embodiment 2 and Embodiment 3. Therefore, according to this embodiment, the effects of both Embodiment 2 and Embodiment 3 can be obtained. That is, according to this embodiment, a large amount of refrigerant can be circulated to the refrigerant passages 72 on the upwind side of each of the plurality of flat tubes 70, as in Embodiment 2, thereby promoting heat exchange between the refrigerant and the air. In addition, according to this embodiment, the pressure of the storage tank space 13 and the first flow path 21 can be increased, as in Embodiment 3, thereby evenly distributing the refrigerant to the plurality of flat tubes 70. Therefore, according to this embodiment, the heat exchange performance of the heat exchanger can be further improved.

[0068] Implementation method 5.

[0069] A refrigeration cycle device according to Embodiment 5 of the present invention will be described. Figure 9 : is a refrigerant circuit diagram showing the structure of the refrigeration cycle device involved in this embodiment. In this embodiment, an air-conditioning device is shown as an example of the refrigeration cycle device, but the refrigeration cycle device of this embodiment can also be applied to a water heater, etc. Figure 9 As shown, the refrigeration cycle device includes a refrigerant circuit 100, which is connected in a ring shape via refrigerant piping to a compressor 101, a four-way valve 102, an indoor heat exchanger 103, a pressure reducing device 104, and an outdoor heat exchanger 105. The refrigeration cycle device also includes an outdoor unit 106 and an indoor unit 107. The outdoor unit 106 houses the compressor 101, the four-way valve 102, the outdoor heat exchanger 105, the pressure reducing device 104, and an outdoor air blower 108 that supplies outdoor air to the outdoor heat exchanger 105. The indoor unit 107 houses the indoor heat exchanger 103 and an indoor air blower 109 that supplies air to the indoor heat exchanger 103. The outdoor unit 106 and the indoor unit 107 are connected via two extension pipes 110 and 111, which form part of the refrigerant piping.

[0070] The compressor 101 is a fluid machine that compresses and discharges the sucked refrigerant. The four-way valve 102 is a device that switches the refrigerant flow path between cooling and heating operations, controlled by a control device (not shown). The indoor heat exchanger 103 performs heat exchange between the refrigerant circulating inside and the indoor air supplied by the indoor blower 109. The indoor heat exchanger 103 functions as a condenser during heating operation and as an evaporator during cooling operation. The pressure reducing device 104 is a device that reduces the pressure of the refrigerant. An electronic expansion valve whose opening is adjusted by the control device can be used as the pressure reducing device 104. The outdoor heat exchanger 105 performs heat exchange between the refrigerant circulating inside and the air supplied by the outdoor blower 108. The outdoor heat exchanger 105 functions as an evaporator during heating operation and as a condenser during cooling operation.

[0071] The heat exchanger according to any one of Embodiments 1 to 4 is used for at least one of the outdoor heat exchanger 105 and the indoor heat exchanger 103. The header 60 is preferably located at a position in the heat exchanger where a large amount of liquid refrigerant is present. Specifically, the header 60 is preferably located on the inlet side of the heat exchanger functioning as an evaporator, or on the outlet side of the heat exchanger functioning as a condenser, in the refrigerant flow of the refrigerant circuit 100.

[0072] Figure 10 : is a refrigerant circuit diagram showing the configuration of a refrigeration cycle device according to a modified example of this embodiment. Figure 10As shown, in this modified example, the outdoor heat exchanger 105 is divided into a heat exchange portion 105a and a heat exchange portion 105b. The heat exchange portions 105a and 105b are connected in series along the flow of the refrigerant. Furthermore, the indoor heat exchanger 103 is divided into a heat exchange portion 103a and a heat exchange portion 103b. The heat exchange portions 103a and 103b are connected in series along the flow of the refrigerant.

[0073] In this variation, the header 60 is also preferably positioned at a location within the heat exchanger where the liquid refrigerant is relatively abundant. Specifically, the header 60 is preferably positioned on the inlet side of the heat exchange sections 105a, 105b, 103a, and 103b that function as evaporators, in the refrigerant flow of the refrigerant circuit 100. In other words, the header 60 is preferably positioned on the outlet side of the heat exchange sections 105a, 105b, 103a, and 103b that function as condensers, in the refrigerant flow of the refrigerant circuit 100.

[0074] As described above, the refrigeration cycle device according to this embodiment includes the heat exchanger according to any one of Embodiments 1 to 4. Preferably, the header 60 is disposed on the inlet side of the heat exchanger, which functions as an evaporator. With this configuration, the refrigeration cycle device can achieve the same effects as those of any one of Embodiments 1 to 4.

[0075] The above-mentioned embodiments 1 to 5 can be implemented in combination with each other.

[0076] Description of Reference Signs

[0077] 10 1st plate-shaped member, 11 bulging portion, 12a, 12b flat portions, 13 storage tank space, 14 closing member, 15 refrigerant inlet, 20 2nd plate-shaped member, 21 1st flow path, 22 2nd flow path, 23 1st connecting flow path, 24 2nd connecting flow path, 25 partition member, 26 upper frame portion, 27 lower frame portion, 30 3rd plate-shaped member, 31 communicating hole, 32 upper frame portion, 33 lower frame portion, 34 closing portion, 35 communicating hole, 40 4th plate-shaped member, 41 insertion hole, 50 5th plate-shaped member, 51 through hole, 52 Insertion space, 60 header, 70 flat tube, 70a first side end, 70b second side end, 70c, 70d flat surfaces, 71 gap, 72 refrigerant passage, 100 refrigerant circuit, 101 compressor, 102 four-way valve, 103 indoor heat exchanger, 103a, 103b heat exchange parts, 104 pressure reducing device, 105 outdoor heat exchanger, 105a, 105b heat exchange parts, 106 outdoor unit, 107 indoor unit, 108 outdoor fan, 109 indoor fan, 110, 111 extension piping.

Claims

1. A heat exchanger, wherein: The heat exchanger has: a plurality of flat tubes arranged vertically parallel to each other and allowing refrigerant to flow therethrough; and A header connected to one end of each of the plurality of flat tubes in the extending direction. The above-mentioned header has: an ascending flow path for circulating the refrigerant upward; a downflow path for circulating the refrigerant downward; a first connecting flow path connecting an upper portion of the ascending flow path and an upper portion of the descending flow path; and a second connecting flow path connecting the lower portion of the ascending flow path and the lower portion of the descending flow path; In the header, a circulation flow path is formed for returning the refrigerant ascending in the ascending flow path through the first connecting flow path, the descending flow path, and the second connecting flow path to the ascending flow path. The circulation flow path is formed by a plurality of plate-shaped members arranged in the extending direction.

2. The heat exchanger according to claim 1, wherein The plurality of plate-like members include: a first plate-shaped member having a refrigerant inlet formed therein; a second plate-shaped member having a first flow path functioning as the ascending flow path, a second flow path functioning as the descending flow path, the first connecting flow path, and the second connecting flow path formed therein; and A third plate-shaped member is formed with at least one communication hole for communicating the first flow path with each of the plurality of flat tubes.

3. The heat exchanger according to claim 2, wherein: The at least one communicating hole has a plurality of communicating holes, The plurality of communication holes are provided at positions corresponding to the plurality of flat tubes, respectively.

4. The heat exchanger according to claim 2, wherein: The at least one communicating hole has a plurality of communicating holes, A flow path cross-sectional area of ​​each of the plurality of communication holes is smaller than a flow path cross-sectional area of ​​each of the plurality of flat tubes.

5. The heat exchanger according to any one of claims 1 to 4, wherein The ascending flow path is arranged on the windward side of a center portion in the major diameter direction of each of the plurality of flat tubes in the flow of air passing through the heat exchanger.

6. The heat exchanger according to any one of claims 1 to 4, wherein A flow path width of the first connecting flow path in the up-down direction is larger than a flow path width of the second connecting flow path in the up-down direction.

7. The heat exchanger according to any one of claims 1 to 4, wherein The first connecting flow channel is located above the uppermost flat tube among the plurality of flat tubes.

8. The heat exchanger according to any one of claims 1 to 4, wherein The second connecting flow path is located below the flat tubes in the lowest layer among the plurality of flat tubes.

9. An outdoor unit, wherein: This outdoor unit includes the heat exchanger according to any one of claims 1 to 4.

10. A refrigeration cycle device, wherein: This refrigeration cycle device includes the heat exchanger according to any one of claims 1 to 4.

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