Heat exchanger and refrigerant circulation device

Abstract

In a heat exchanger (100), a refrigerant flows in the longitudinal direction (DL) between a second flow hole (120b) on the upper side and a second flow hole (120b) on the lower side. A heat exchanger (100) is provided with a first heat transfer plate (110) and a second heat transfer plate (120) in which N flow path regions (F1-F5) arranged adjacent to each other in the longitudinal direction (DL) are formed. The number and cross-sectional area of flow paths in the first flow path region (F1) are different from the number and cross-sectional area of flow paths in the Nth flow path region (F5). The first flow path region (F1) is the first flow path region from the upper second flow hole (120b) side in the longitudinal direction (DL) among the N flow path regions. The Nth flow path region (F5) is the Nth flow path region from the upper second flow hole (120b) side in the longitudinal direction (DL) among the N flow path regions.

Description

Technical Field

[0001] The invention relates to a heat exchanger and a refrigeration cycle device. Background Art

[0002] Conventionally, a heat exchanger including a heat transfer member having a plurality of heat exchange flow paths for performing heat exchange on a fluid and branch flow paths for distributing the fluid to each heat exchange path is used. Summary of the invention

[0003] Problems to be solved by the invention

[0004] Patent document 1 (Japanese Patent Publication No. 2016-90157) discloses a plate-fin heat exchanger having a metal plate, which is formed with a plurality of heat exchange channels and a pair of branch channels connected to both ends of the heat exchange channels. In such a conventional heat exchanger, the fluid introduced into the heat exchanger is diverted to all the heat exchange channels through the branch channels near the inlet of the heat exchanger, and merges through the branch channels near the outlet of the heat exchanger. Therefore, the number and cross-sectional area of ​​the heat exchange channels are mostly constant from near the inlet to near the outlet of the heat exchanger. In this case, in the heat exchange channel near the inlet for the flow of gaseous fluid, the pressure loss sometimes increases, resulting in a decrease in the performance of the heat exchanger. In addition, in the heat exchange channel near the outlet for the flow of liquid fluid, the flow rate of the fluid sometimes decreases, resulting in a decrease in the heat transfer efficiency.

[0005] Means for solving problems

[0006] The heat exchanger of the first aspect is a heat exchanger in which a fluid flows between a first opening and a second opening along a first direction. The heat exchanger has a component formed with N (N is an integer greater than or equal to 2) flow path areas arranged adjacently along a first direction between the first opening and the second opening. The N flow path areas each have a flow path for fluid flow. The number and cross-sectional area of ​​the flow paths in the first flow path area are different from the number and cross-sectional area of ​​the flow paths in the Nth flow path area. The first flow path area is the first one from the first opening side in the first direction among the N flow path areas. The Nth flow path area is the Nth one from the first opening side in the first direction among the N flow path areas.

[0007] In the heat exchanger of the first aspect, a flow path for fluid flow is formed in such a way that an appropriate flow rate of the fluid is achieved according to the phase change (density change) of the fluid flowing inside the heat exchanger. Therefore, it is possible to suppress the situation where the pressure loss in the flow path near the inlet for the gaseous fluid to flow increases, thereby reducing the performance of the heat exchanger. In addition, it is possible to suppress the situation where the flow rate of the fluid in the flow path near the outlet for the liquid fluid to flow decreases, thereby reducing the heat transfer efficiency.

[0008] The heat exchanger of the second aspect is that, in the heat exchanger of the first aspect, the number of flow paths in the i-th flow path region is less than the number of flow paths in the j-th flow path region, and the cross-sectional area of ​​the flow paths in the i-th flow path region is larger than the cross-sectional area of ​​the flow paths in the j-th flow path region. The i-th flow path region is the i-th from the first opening side in the first direction among the N flow path regions. The j-th flow path region is the j-th from the first opening side in the first direction among the N flow path regions (i, j are integers satisfying 1≤i<j≤N).

[0009] In the heat exchanger of the second aspect, the flow path cross-sectional area gradually decreases from the gas side (inlet side) toward the liquid side (outlet side), so the pressure loss on the gas side is reduced, and the flow rate of the fluid on the liquid side is ensured. In addition, the number of flow paths gradually increases from the gas side toward the liquid side, so even if the flow path cross-sectional area decreases from the gas side toward the liquid side, the reduction in the heat transfer area of ​​the fluid can be suppressed.

[0010] A heat exchanger according to a third aspect is the heat exchanger according to the first aspect or the second aspect, wherein the number of flow paths in the first flow path region is one.

[0011] The heat exchanger of the fourth aspect is the heat exchanger of the third aspect, wherein the distance L1 and the distance L0 satisfy the relationship of 0.2×L0≤L1≤0.8×L0. The distance L1 is the distance between the boundary between the second flow path region and the first flow path region and the first opening in the first direction. The distance L0 is the distance between the first opening and the second opening in the first direction. The second flow path region is the second one from the first opening side in the first direction among the N flow path regions.

[0012] The heat exchanger of the fifth aspect is the heat exchanger of the fourth aspect, wherein the distance L2 and the distance L0 satisfy the relationship of 0.2×L0≤L2≤0.8×L0. The distance L2 is the distance in the first direction between the boundary of two flow path areas adjacent in the first direction among the N flow path areas and the first opening. The distance L0 is the distance in the first direction between the first opening and the second opening.

[0013] The heat exchanger of the sixth aspect is a heat exchanger according to any one of the first to fifth aspects, wherein the flow path branches at the boundary between the kth flow path region and the k+1th flow path region, and the number of flow paths in the k+1th flow path region is 2 to 4 times the number of flow paths in the kth flow path region. The kth flow path region is the kth (k is an integer satisfying 1≤k≤N-1) from the first opening side in the first direction among the N flow path regions. The k+1th flow path region is the k+1th from the first opening side in the first direction among the N flow path regions.

[0014] A heat exchanger according to a seventh aspect is the heat exchanger according to any one of the first to sixth aspects, wherein a length of each of the N flow path regions in the first direction is 10% to 50% of a distance between the first opening and the second opening in the first direction.

[0015] A heat exchanger according to an eighth aspect is the heat exchanger according to any one of the first to seventh aspects, comprising a plurality of members stacked in a second direction intersecting the first direction. The N flow path regions are formed between members adjacent to each other in the second direction.

[0016] The heat exchanger of the ninth aspect is the heat exchanger of the eighth aspect, wherein N flow path regions having flow paths for a first medium as a fluid to flow and N flow path regions having flow paths for a second medium as a fluid to flow are alternately stacked in the second direction. The first medium flows in the flow path from the first opening toward the second opening. The second medium flows in the flow path from the second opening toward the first opening.

[0017] A refrigeration cycle device according to a tenth aspect includes the heat exchanger according to any one of the first to ninth aspects. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic configuration diagram of a refrigeration cycle device 1 including a heat exchanger 100 .

[0019] Figure 2 It is an exploded perspective view of the heat exchanger 100 .

[0020] Figure 3 is a cross-sectional view of the heat exchanger 100 .

[0021] Figure 4 It is a top view of the first heat transfer plate 110 .

[0022] Figure 5 It is a top view of the second heat transfer plate 120 .

[0023] Figure 6 It is a top view of the second heat transfer plate 120 .

[0024] Figure 7 1 is a plan view of the second heat transfer plate 120 in Modification A.

[0025] Figure 8 1 is a plan view of the second heat transfer plate 120 in Modification B. DETAILED DESCRIPTION

[0026] (1) Refrigeration cycle device 1

[0027] A refrigeration cycle device 1 including a heat exchanger 100 according to an embodiment of the present disclosure will be described. The refrigeration cycle device 1 is a binary refrigeration device that performs cooling of an air-conditioning target space (not shown) such as a room of a building by executing a vapor compression cycle.

[0028] like Figure 1 As shown, the refrigerant cycle device 1 has a heat source side cycle 10 and a utilization side cycle 20. The heat source side cycle 10 is a vapor compression cycle that circulates the refrigerant. The refrigerant is, for example, R1234ze. The utilization side cycle 20 is a vapor compression cycle that circulates a heat medium that is a fluid having a lower boiling point than the refrigerant. The heat medium is, for example, carbon dioxide. Heat exchange between the refrigerant and the heat medium is performed in a heat exchanger 100.

[0029] (1-1) Heat exchanger 100

[0030] The heat exchanger 100 is a cascade condenser that performs heat exchange between a refrigerant and a heat medium. The heat exchanger 100 functions as an evaporator of the refrigerant and as a condenser of the heat medium. The heat exchanger 100 includes a first inlet pipe 150a, a first outlet pipe 150b, a second inlet pipe 160a, a second outlet pipe 160b, a first flow path 111, and a second flow path 121.

[0031] The first flow path 111 is a flow path for the refrigerant to flow. The first flow path 111 is formed between the first inlet pipe 150a and the first outlet pipe 150b. The second flow path 121 is a flow path for the heat medium to flow. The second flow path 121 is formed between the second inlet pipe 160a and the second outlet pipe 160b. The detailed structure of the heat exchanger 100 will be described later.

[0032] (1-2) Heat source side cycle 10

[0033] The heat source side cycle 10 is composed of a heat source side compressor 11, a heat source side heat exchanger 12, a heat source side expansion valve 13, and a first inlet pipe 150a, a first outlet pipe 150b, and a first flow path 111 of the heat exchanger 100. The heat source side cycle 10 is installed outside the air-conditioned space.

[0034] The heat source side compressor 11 sucks the low-pressure gas phase refrigerant in the heat source side cycle 10 from the first suction part 11a, compresses it and discharges it from the first discharge part 11b as the high-pressure gas phase refrigerant. The heat source side heat exchanger 12 functions as a condenser and performs heat exchange between the refrigerant and the outside air (the air outside the air-conditioned space). The heat source side expansion valve 13 adjusts the flow rate of the refrigerant circulating in the heat source side cycle 10. The heat source side expansion valve 13 functions as a decompression device that decompresses the refrigerant.

[0035] The first discharge portion 11b of the heat source side compressor 11 is connected to one end of the heat source side heat exchanger 12. The other end of the heat source side heat exchanger 12 is connected to one end of the heat source side expansion valve 13. The other end of the heat source side expansion valve 13 is connected to the first inlet pipe 150a of the heat exchanger 100. The first outlet pipe 150b of the heat exchanger 100 is connected to the first suction portion 11a of the heat source side compressor 11.

[0036] (1-3) Using side circulation 20

[0037] The utilization side cycle 20 is constituted by a utilization side compressor 21, a utilization side heat exchanger 22, a utilization side expansion valve 23, and the second inlet pipe 160a, the second outlet pipe 160b, and the second flow path 121 of the heat exchanger 100. The utilization side cycle 20 is installed in the air-conditioned space.

[0038] The utilization side compressor 21 sucks the low-pressure gas phase heat medium in the utilization side cycle 20 from the second suction part 21a, compresses it and discharges it from the second discharge part 21b as a high-pressure gas phase heat medium. The utilization side heat exchanger 22 functions as an evaporator and performs heat exchange between the heat medium and the air in the air-conditioned space. The utilization side expansion valve 23 adjusts the flow rate of the heat medium circulating in the utilization side cycle 20. The utilization side expansion valve 23 functions as a decompression device that decompresses the heat medium.

[0039] The second discharge portion 21b of the utilization side compressor 21 is connected to the second inlet pipe 160a of the heat exchanger 100. The second outlet pipe 160b of the heat exchanger 100 is connected to one end of the utilization side expansion valve 23. The other end of the utilization side expansion valve 23 is connected to one end of the utilization side heat exchanger 22. The other end of the utilization side heat exchanger 22 is connected to the first suction portion 11a of the utilization side compressor 21.

[0040] (1-4) Action

[0041] The operation of the heat source side cycle 10 and the utilization side cycle 20 in the operation of the refrigeration cycle device 1 will be described. When the refrigeration cycle device 1 starts to operate, the control unit (not shown) drives the heat source side compressor 11 and the utilization side compressor 21, and sets the opening of the heat source side expansion valve 13 and the utilization side expansion valve 23 to an appropriate opening corresponding to the air conditioning load.

[0042] (1-4) Operation of heat source side cycle 10

[0043] The heat source side compressor 11 inhales the low-pressure gas phase refrigerant in the heat source side cycle 10 from the first suction part 11a, and discharges it from the first discharge part 11b as the high-pressure gas phase refrigerant. The high-pressure gas phase refrigerant reaches the heat source side heat exchanger 12. The heat source side heat exchanger 12 condenses the high-pressure gas phase refrigerant to become a high-pressure liquid phase refrigerant. At this time, the refrigerant releases heat to the outside air. The high-pressure liquid phase refrigerant reaches the heat source side expansion valve 13. The heat source side expansion valve 13 set to an appropriate opening decompresses the high-pressure liquid phase refrigerant to form a low-pressure gas-liquid two-phase refrigerant. The low-pressure gas-liquid two-phase refrigerant enters the first flow path 111 through the first inlet pipe 150a of the heat exchanger 100. The heat exchanger 100 evaporates the low-pressure gas-liquid two-phase refrigerant to become a low-pressure gas phase refrigerant. At this time, the refrigerant absorbs heat from the heat medium passing through the second flow path 121 of the heat exchanger 100. The low-pressure gas-phase refrigerant flows out of the first flow path 111 through the first outlet pipe 150 b , and is sucked into the heat-source-side compressor 11 through the first suction portion 11 a .

[0044] (1-4) Using the side loop 20

[0045] The utilization side compressor 21 sucks the low-pressure gas phase heat medium in the utilization side cycle 20 from the second suction part 21a, and discharges it from the second discharge part 21b as a high-pressure gas phase heat medium. The high-pressure gas phase heat medium enters the second flow path 121 through the second inlet pipe 160a of the heat exchanger 100. The heat exchanger 100 condenses the high-pressure gas phase heat medium to become a high-pressure liquid phase heat medium. At this time, the heat medium releases heat to the refrigerant passing through the first flow path 111 of the heat exchanger 100. The high-pressure liquid phase heat medium leaves the second flow path 121 through the second outlet pipe 160b and reaches the utilization side expansion valve 23. The utilization side expansion valve 23 set to an appropriate opening reduces the pressure of the high-pressure liquid phase heat medium to make it a low-pressure gas-liquid two-phase heat medium. The low-pressure gas-liquid two-phase heat medium reaches the utilization side heat exchanger 22. The utilization side heat exchanger 22 evaporates the low-pressure gas-liquid two-phase heat medium to become a low-pressure gas phase heat medium. At this time, the heat medium absorbs heat from the air in the air-conditioned space. The heat medium in the low-pressure gas phase leaves the use-side heat exchanger 22 and is sucked into the use-side compressor 21 from the second suction portion 21a.

[0046] (2) Heat exchanger 100

[0047] (2-1) Overall structure

[0048] like Figure 2 As shown, the heat exchanger 100 is a plate heat exchanger including a plurality of first heat transfer plates 110, a plurality of second heat transfer plates 120, a first frame 130, and a second frame 140. The heat exchanger 100 has a first flow path 111 and a second flow path 121 formed therein.

[0049] The first heat transfer plate 110 and the second heat transfer plate 120 are metal plate-shaped members having the same rectangular shape. Figure 2 As shown, the first heat transfer plate 110 , the second heat transfer plate 120 , the first frame 130 , and the second frame 140 are formed in a rectangular shape extending along the longitudinal direction DL.

[0050] The plurality of first heat transfer plates 110 and the plurality of second heat transfer plates 120 are alternately stacked between the first frame 130 and the second frame 140. The number of each of the plurality of first heat transfer plates 110 and the plurality of second heat transfer plates 120 is not limited, and is appropriately set according to the required performance. The material and size of the first frame 130, the first heat transfer plate 110, the second heat transfer plate 120, and the second frame 140 are not limited, and are appropriately set according to the required performance. The first frame 130, the first heat transfer plate 110, the second heat transfer plate 120, and the second frame 140 are integrally joined, for example, by brazing.

[0051] In the following description, the direction in which the first heat transfer plate 110 and the second heat transfer plate 120 are stacked is referred to as a stacking direction DS, and the direction perpendicular to the length direction DL and the stacking direction DS is referred to as a width direction DW. Figure 2 As shown in FIG. 1 , directions such as “up”, “down”, “left”, “right”, “front” and “rear” are defined. The length direction DL is the up-down direction. The width direction DW is the left-right direction. The stacking direction DS is the front-rear direction.

[0052] (2-2) Detailed structure

[0053] (2-2-1) First heat transfer plate 110

[0054] The first heat transfer plate 110 is a corrugated fin having a corrugated cross section. Figure 2 and Figure 3 As shown, the corrugated surface of the first heat transfer plate 110 is formed so as to draw a herringbone pattern with the top portion convex upward in a plan view.

[0055] The first heat transfer plate 110 forms a first flow path 111 and a second flow path 121 together with the adjacently stacked second heat transfer plate 120. The first heat transfer plate 110 has a first joint region 110a, two first flow holes 110b, two first through holes 110c, a first front surface 110sa, and a first rear surface 110sb.

[0056] The first joining region 110a is a region for mutually joining the first heat transfer plate 110 and the second heat transfer plate 120. The first joining region 110a is a band-shaped region in which an edge of a predetermined width is bent toward the front side.

[0057] The first flow hole 110b is a circular hole that introduces the refrigerant into the first flow path 111 or guides the refrigerant out of the first flow path 111. The first flow hole 110b is formed on the upper left side and the lower right side of the first heat transfer plate 110.

[0058] The first through hole 110 c is a circular hole that allows the heat medium to pass in the stacking direction DS. The first through hole 110 c is formed on the upper right side and the lower left side of the first heat transfer plate 110 .

[0059] The first front surface 110sa is a surface on the front side of the first heat transfer plate 110. The first front surface 110sa is a surface facing a second rear surface 120sb of the second heat transfer plate 120 described later when the first heat transfer plate 110 and the second heat transfer plate 120 are stacked.

[0060] The first rear surface 110sb is a surface on the rear side of the first heat transfer plate 110. The first rear surface 110sb is a surface facing a second front surface 120sa of a second heat transfer plate 120 described later when the first heat transfer plate 110 and the second heat transfer plate 120 are stacked.

[0061] The first heat transfer plate 110 may be produced by any method without limitation, and may be formed by, for example, press working.

[0062] (2-2-2) Second heat transfer plate 120

[0063] The second heat transfer plate 120 forms the first flow path 111 and the second flow path 121 together with the adjacently stacked first heat transfer plate 110. The second heat transfer plate 120 has a second joining region 120a, two second flow holes 120b, two second through holes 120c, a second front surface 120sa, and a second rear surface 120sb.

[0064] The second joining region 120a is a region for joining the first heat transfer plate 110 and the second heat transfer plate 120. The second joining region 120a is a band-shaped region in which an edge of a predetermined width is bent toward the front side.

[0065] The second flow hole 120b is a circular hole for introducing the heat medium into the second flow path 121 or for guiding the heat medium out from the second flow path 121. The second flow hole 120b is formed on the upper right side and the lower left side of the second heat transfer plate 120. The second flow hole 120b is formed at a position that overlaps and communicates with the first through hole 110c when the first heat transfer plate 110 and the second heat transfer plate 120 are stacked. The size and shape of the second flow hole 120b are the same as those of the first through hole 110c.

[0066] The second through hole 120c is a circular hole that allows the refrigerant to pass in the stacking direction DS. The second through hole 120c is formed on the upper left side and the lower right side of the second heat transfer plate 120. The second through hole 120c is formed at a position that overlaps and communicates with the first flow hole 110b when the first heat transfer plate 110 and the second heat transfer plate 120 are stacked. The size and shape of the second through hole 120c are the same as those of the first flow hole 110b.

[0067] The second front surface 120sa is a surface on the front side of the second heat transfer plate 120. The second front surface 120sa is a surface facing the first rear surface 110sb of the first heat transfer plate 110 when the first heat transfer plate 110 and the second heat transfer plate 120 are stacked.

[0068] The second rear surface 120sb is a surface on the rear side of the second heat transfer plate 120. The second rear surface 120sb is a surface facing the first front surface 110sa of the first heat transfer plate 110 when the first heat transfer plate 110 and the second heat transfer plate 120 are stacked.

[0069] The manufacturing method of the second heat transfer plate 120 is not limited, and the second heat transfer plate 120 may be formed by, for example, press working. The shape of the second heat transfer plate 120 will be described in detail later.

[0070] (2-2-3) First Frame 130 and Second Frame 140

[0071] The first frame 130 and the second frame 140 are metal plate-shaped members that sandwich the plurality of first heat transfer plates 110 and the plurality of second heat transfer plates 120 that are alternately stacked at both ends in the stacking direction DS.

[0072] (2-2-4) First Inlet Pipe 150a and First Outlet Pipe 150b

[0073] The first introduction pipe 150a is a pipe for introducing the refrigerant into the first flow path 111. The first introduction pipe 150a is provided so as to penetrate the upper left side of the first frame 130 and communicate with the first flow path 111. More specifically, the first introduction pipe 150a is formed so as to communicate with the first flow hole 110b and the second through hole 120c formed on the upper left side, which communicate with each other when the first heat transfer plate 110, the second heat transfer plate 120 and the first frame 130 are stacked.

[0074] The first outlet pipe 150b is a pipe for outlet refrigerant from the first flow path 111. The first outlet pipe 150b is provided so as to penetrate the lower right side of the first frame 130 and communicate with the first flow path 111. More specifically, the first outlet pipe 150b is formed so as to communicate with the first flow hole 110b and the second through hole 120c formed on the lower right side and communicate with each other when the first heat transfer plate 110, the second heat transfer plate 120 and the first frame 130 are stacked.

[0075] (2-2-5) Second Inlet Pipe 160a and Second Outlet Pipe 160b

[0076] The second introduction pipe 160a is a pipe for introducing the heat medium into the second flow path 121. The second introduction pipe 160a is provided so as to penetrate the upper right side of the first frame 130 and communicate with the second flow path 121. More specifically, the second introduction pipe 160a is formed so as to communicate with the second flow hole 120b and the first through hole 110c formed on the upper right side and communicate with each other when the first heat transfer plate 110, the second heat transfer plate 120 and the first frame 130 are stacked.

[0077] The second outlet pipe 160b is a pipe for extracting the heat medium from the second flow path 121. The second outlet pipe 160b is provided so as to penetrate the lower left side of the first frame 130 and communicate with the second flow path 121. More specifically, the second inlet pipe 160a is formed so as to communicate with the second flow hole 120b and the first through hole 110c formed on the lower left side and communicate with each other when the first heat transfer plate 110, the second heat transfer plate 120 and the first frame 130 are stacked.

[0078] (2-2-6) First flow path 111 and second flow path 121

[0079] like Figure 3 As shown in the figure, by alternately stacking the first heat transfer plate 110 and the second heat transfer plate 120, the first flow path 111 and the second flow path 121 are alternately formed in the stacking direction DS. More specifically, by alternately stacking the first heat transfer plate 110 and the second heat transfer plate 120, the space where the first front surface 110sa of the first heat transfer plate 110 and the second rear surface 120sb of the second heat transfer plate 120 face each other becomes the first flow path 111. In addition, by alternately stacking the first heat transfer plate 110 and the second heat transfer plate 120, the space where the first rear surface 110sb of the first heat transfer plate 110 and the second front surface 120sa of the second heat transfer plate 120 face each other becomes the second flow path 121.

[0080] The first heat transfer plate 110 and the second heat transfer plate 120 are joined together by brazing. More specifically, the first heat transfer plate 110 and the second heat transfer plate 120 are joined together at the first joining region 110a and the second joining region 120a by brazing.

[0081] In the following description, the first flow path 111 represents a rectangular region located between the first flow hole 110b on the upper side and the first flow hole 110b on the lower side, and the dimension in the width direction DW is constant in the length direction DL. Similarly, the second flow path 121 represents a rectangular region located between the second flow hole 120b on the upper side and the second flow hole 120b on the lower side, and the dimension in the width direction DW is constant in the length direction DL. Figure 4 and Figure 5 1 and 12 show the ranges of the first flow path 111 and the second flow path 121 in the length direction DL and the width direction DW, respectively.

[0082] (2-3) Flow of refrigerant and heat medium

[0083] The refrigerant introduced from the first inlet pipe 150a of the heat exchanger 100 flows into the first flow path 111 through the second through hole 120c and the first flow hole 110b on the upper side. The refrigerant flowing into the first flow path 111 flows toward the first flow hole 110b on the lower side in the first flow path 111. The refrigerant reaching the first flow hole 110b on the lower side is discharged from the first outlet pipe 150b through the second through hole 120c on the lower side. During this period, the liquid refrigerant flowing in the first flow path 111 exchanges heat with the heat medium of the second flow path 121 adjacent to the first heat transfer plate 110 or the second heat transfer plate 120, and evaporates to become a gaseous refrigerant. In other words, the heat exchanger 100 functions as an evaporator of the refrigerant.

[0084] On the other hand, the heat medium introduced from the second inlet pipe 160a of the heat exchanger 100 flows into the second flow path 121 through the second flow hole 120b on the upper side and the first through hole 110c. The heat medium flowing into the second flow path 121 flows toward the second flow hole 120b on the lower side in the second flow path 121. The heat medium reaching the second flow hole 120b on the lower side is discharged from the second outlet pipe 160b through the first through hole 110c on the lower side. During this period, the gaseous heat medium flowing in the second flow path 121 exchanges heat with the refrigerant of the first flow path 111 adjacent to the first heat transfer plate 110 or the second heat transfer plate 120, and condenses to become a liquid heat medium. In other words, the heat exchanger 100 functions as a condenser of the heat medium.

[0085] (2-4) Detailed Structure of Second Flow Path 121

[0086] In the heat exchanger 100, the heat medium flowing in the second flow path 121 flows along the length direction DL between the second flow hole 120b on the upper side and the second flow hole 120b on the lower side. In the present embodiment, the heat medium flows in from the second flow hole 120b on the upper side, flows out from the second flow hole 120b on the lower side after passing through the second flow path 121. The second flow hole 120b on the upper side is connected to the second introduction pipe 160a via the first through hole 110c on the upper side. The second flow hole 120b on the lower side is connected to the second outlet pipe 160b via the first through hole 110c on the lower side. The gaseous heat medium before heat exchange in the heat exchanger 100 flows from the second introduction pipe 160a through the second flow hole 120b on the upper side into the second flow path 121. In the process of passing through the second flow path 121, the gaseous heat medium undergoes heat exchange and becomes liquid. The liquid heat medium flows out of the second flow path 121 and is supplied to the second outlet pipe 160 b through the second flow hole 120 b on the lower side.

[0087] The first heat transfer plate 110 and the second heat transfer plate 120 form N flow path areas. The value N is an integer greater than 2. In this embodiment, Figure 6 As shown, the value N is 5, and the first heat transfer plate 110 and the second heat transfer plate 120 form five flow path areas F1 to F5. Each flow path area F1 to F5 has a portion of the second flow path 121. Each flow path area F1 to F5 is a rectangular area arranged adjacent to each other along the length direction DL between the second flow hole 120b on the upper side and the second flow hole 120b on the lower side. The size of each flow path area F1 to F5 in the width direction DW is equal to the size of the second flow path 121 in the width direction DW.

[0088] In the following description, the xth flow path region from the second flow hole 120b side on the upper side in the longitudinal direction DL among the N flow path regions is referred to as the xth flow path region. The value x is an integer satisfying 1≤x≤N. For example, Figure 6 , the first flow path region F1 is located below the second flow hole 120b on the upper side, and the second flow path region F2 is located below the first flow path region F1. In addition, the fifth flow path region F5 (Nth flow path region) is located below the fourth flow path region F4 and above the second flow hole 120b on the lower side. In this way, the first flow path region to the Nth flow path region are adjacently arranged in a row along the length direction DL from the second flow hole 120b on the upper side toward the second flow hole 120b on the lower side.

[0089] Each flow path region F1 to F5 has one or more flow path elements 131. The flow path element 131 is a space where the heat medium flows along the length direction DL. When a flow path region has a plurality of flow path elements 131, the plurality of flow path elements 131 are arranged along the width direction DW. Two flow path elements 131 adjacent to each other in the width direction DW are separated by a partition element 132 extending along the length direction DL. Figures 5 to 8 , the separation elements 132 are shown as shaded areas.

[0090] like Figure 3 As shown in FIG. 1 , the flow path element 131 corresponds to a space formed by the first rear surface 110sb of the first heat transfer plate 110 and the second front surface 120sa of the second heat transfer plate 120 facing each other. In addition, the partition element 132 corresponds to a portion where the first rear surface 110sb of the first heat transfer plate 110 and the second front surface 120sa of the second heat transfer plate 120 are joined. When the flow path region has a plurality of flow path elements 131, the plurality of flow path elements 131 have the same size in the width direction DW and the same cross-sectional area.

[0091] In two adjacent flow path regions in the longitudinal direction DL, the number and cross-sectional area of ​​the flow path elements 131 are different from each other. In addition, in each flow path region F1 to F5, the number and cross-sectional area of ​​the flow path elements 131 are fixed. Therefore, when N flow path regions are formed, the number and cross-sectional area of ​​the flow path elements 131 in the first flow path region are different from the number and cross-sectional area of ​​the flow path elements 131 in the Nth flow path region.

[0092] Specifically, when the values ​​i and j are integers satisfying 1≤i<j≤N, the number of flow path elements 131 in the i-th flow path region is smaller than the number of flow path elements 131 in the j-th flow path region, and the cross-sectional area of ​​the flow path elements 131 in the i-th flow path region is larger than the cross-sectional area of ​​the flow path elements 131 in the j-th flow path region. Figure 6 As shown, the second flow path region F2 has two flow path elements 131, and the third flow path region F3 has four flow path elements 131. In this case, the size of the flow path elements 131 in the second flow path region F2 in the width direction DW is larger than the size of the flow path elements 131 in the third flow path region F3 in the width direction DW. Therefore, the cross-sectional area of ​​the flow path elements 131 in the second flow path region F2 is larger than the cross-sectional area of ​​the flow path elements 131 in the third flow path region F3.

[0093] In addition, in this embodiment, if Figure 6 As shown, the number of the flow path elements 131 in the first flow path region F1 is 1. In other words, the first flow path region F1 does not have the partition element 132 .

[0094] Furthermore, in this embodiment, if Figure 6As shown, a confluence region 133 is formed between the fifth flow path region F5 (Nth flow path region) and the second flow hole 120b at the lower side. The confluence region 133 is connected to all the flow path elements 131 of the fifth flow path region F5. The size of the confluence region 133 in the longitudinal direction DL is preferably less than 20% of the size of the second flow path 121 in the longitudinal direction DL.

[0095] Therefore, from the second flow hole 120b on the upper side toward the second flow hole 120b on the lower side, the number of flow path elements 131 in the flow path regions F1 to F5 gradually increases, and the cross-sectional area of ​​the flow path elements 131 in the flow path regions F1 to F5 gradually decreases. In other words, in the process where the gaseous heat medium flows in the second flow path 121 and becomes a liquid heat medium, the number of the flow path elements 131 through which the heat medium flows gradually increases, and the cross-sectional area of ​​the flow path elements 131 gradually decreases.

[0096] In addition, in the second flow path 121, the boundary between two adjacent flow path areas in the longitudinal direction DL is a position where the number and cross-sectional area of ​​the flow path elements 131 change. Therefore, in the second flow path 121, the flow of the heat medium gradually branches in the process of flowing from the first flow path area F1 to the fifth flow path area F5. The heat medium that has passed through the flow path elements 131 in the fifth flow path area F5 merges in the merging area 133 and is supplied to the second flow hole 120b on the lower side.

[0097] exist Figure 6 , the numbers of the flow path elements 131 in the first flow path region F1 to the fifth flow path region F5 are 1, 2, 4, 8, and 16, respectively. In other words, when the heat medium flows from the first flow path region F1 to the second flow hole 120b on the lower side, the number of the flow path elements 131 doubles each time the flow of the heat medium branches.

[0098] The number of each flow path region F1 to F5 and the size in the longitudinal direction DL are not limited and can be appropriately set according to the required performance. In addition, the number of flow path elements 131 in each flow path region F1 to F5 is not limited and can be appropriately set according to the required performance. For example, the first flow path region F1 may have one flow path element 131 and the second flow path region F2 may have ten flow path elements 131. In this case, when the heat medium flows from the second flow path region F2 to the second flow hole 120b on the lower side, the number of flow path elements 131 can be doubled each time the flow of the heat medium branches.

[0099] (3) Features

[0100] (3-1)

[0101] In the past, a plate-fin heat exchanger having a metal plate formed with a plurality of heat exchange channels for heat exchange of fluids and a pair of branch channels connected to both ends of the heat exchange channels has been used. In such a heat exchanger, the fluid flowing into the heat exchanger is diverted to all the heat exchange channels through the branch channels near the inlet of the heat exchanger, and merges through the branch channels near the outlet of the heat exchanger. Therefore, the number and cross-sectional area of ​​the heat exchange channels are constant from near the inlet to near the outlet of the heat exchanger. In the case where a gaseous fluid is phase-changed into a liquid fluid by heat exchange in the heat exchange channel, the pressure loss in the heat exchange channel near the inlet for the gaseous fluid to flow increases, which may lead to a decrease in the performance of the heat exchanger. In addition, in the heat exchange channel near the outlet for the liquid fluid to flow, the flow rate of the fluid decreases, which may lead to a decrease in the heat transfer efficiency.

[0102] The heat exchanger 100 of the present embodiment includes a first heat transfer plate 110 and a second heat transfer plate 120 that are alternately stacked. The first heat transfer plate 110 and the second heat transfer plate 120 form a second flow path 121, wherein in the second flow path 121, the gaseous heat medium is condensed by heat exchange to become a liquid heat medium. In the second flow path 121, in the process of the heat medium flowing from the inlet side for the gaseous heat medium to flow in toward the outlet side for the liquid heat medium to flow out, the flow of the heat medium gradually branches, and the cross-sectional area of ​​the flow path element 131 for the heat medium to flow gradually decreases. The larger the cross-sectional area of ​​the flow path near the inlet for the gaseous heat medium to flow, the easier it is to reduce the pressure loss. The smaller the cross-sectional area of ​​the flow path near the outlet for the liquid heat medium to flow, the easier it is to suppress the reduction in the flow rate of the heat medium. Therefore, in the heat exchanger 100 , the second flow path 121 is formed such that the cross-sectional area of ​​the flow path element 131 through which the heat medium flows gradually decreases so as to achieve an appropriate flow rate of the heat medium according to the phase change (density change) of the heat medium flowing in the second flow path 121 .

[0103] Therefore, in the heat exchanger 100 of the present embodiment, it is possible to suppress the pressure loss in the flow path near the inlet for the gaseous fluid to flow, thereby suppressing the performance reduction of the heat exchanger. In addition, in the heat exchanger 100 of the present embodiment, it is possible to suppress the flow velocity of the fluid in the flow path near the outlet for the liquid fluid to flow, thereby suppressing the heat transfer efficiency from being reduced.

[0104] (3-2)

[0105] In the heat exchanger 100 of this embodiment, in the second flow path 121, as the heat medium flows from the inlet side where the gaseous heat medium flows in toward the outlet side where the liquid heat medium flows out, the flow of the heat medium gradually branches, and the number of flow path elements 131 through which the heat medium flows gradually increases.

[0106] Therefore, in the heat exchanger 100 of this embodiment, even if the cross-sectional area of ​​the flow path for the fluid to flow from the inlet side toward the outlet side gradually decreases, the reduction in the flow rate of the fluid and the reduction in the area of ​​the part that contributes to the heat exchange of the fluid (heat transfer area) can be suppressed, thereby suppressing the reduction in heat transfer efficiency.

[0107] (4) Modification

[0108] (4-1) Modification A

[0109] Next, in Modifications A to D, specific examples of the second flow path 121 of the above-described embodiment will be described. Figure 7-8 is with Figure 6 The second heat transfer plate 120 is also shown in a top view.

[0110] exist Figure 7 , the distance L0 is the distance between the second flow hole 120b on the upper side and the second flow hole 120b on the lower side in the length direction DL. The position of the second flow hole 120b is the center of the circular shape of the second flow hole 120b. The distance L0 is the distance in the length direction DL that the heat medium flowing in from the second flow hole 120b on the upper side and flowing out from the second flow hole 120b on the lower side moves in the space between the first heat transfer plate 110 and the second heat transfer plate 120. The distance L1 is the distance in the length direction DL between the boundary B1 between the first flow path area F1 and the second flow path area F2 and the second flow hole 120b on the upper side.

[0111] In the above embodiment, the distance L0 and the distance L1 preferably satisfy the relationship of 0.2×L0≤L1≤0.8×L0. In this case, the position where the flow of the heat medium is initially branched in the longitudinal direction DL is at a position of 20% to 80% of the distance L0 corresponding to the length of the flow path of the heat medium. The position where the flow of the heat medium is initially branched corresponds to the position of the boundary B1 in the longitudinal direction DL.

[0112] (4-2) Modification B

[0113] exist Figure 8 , the distance L0 is the distance between the second flow hole 120b on the upper side and the second flow hole 120b on the lower side in the length direction DL. The position of the second flow hole 120b is the center of the circular shape of the second flow hole 120b. The distance L0 is the distance in the length direction DL that the heat medium flowing in from the second flow hole 120b on the upper side and flowing out from the second flow hole 120b on the lower side moves in the space between the first heat transfer plate 110 and the second heat transfer plate 120. The distance L2 is the distance in the length direction DL between the boundary of two adjacent flow path areas in the length direction DL and the second flow hole 120b on the upper side.

[0114] exist Figure 8 In FIG. 1 , the boundaries B1 to B4 of two flow path regions adjacent to each other in the longitudinal direction DL are shown from the upper second flow hole 120 b toward the lower second flow hole 120 b. The number of boundaries is 1 less than the number of flow path regions. Figure 8 5 flow path regions F1 to F5 and 4 boundaries B1 to B4 are shown in FIG. In the longitudinal direction DL, the boundaries B1 to B4 are located at positions where the flow of the heat medium branches. Figure 8 In FIG. 1 , the distance L2 is represented as the distance between the boundary B2 and the upper second flow hole 120 b in the longitudinal direction DL.

[0115] In the above embodiment, the distance L0 and the distance L2 preferably satisfy the relationship of 0.2×L0≤L2≤0.8×L0. In this case, in the longitudinal direction DL, the positions where the flow of the heat medium branches are all located at 20% to 80% of the distance L0 corresponding to the length of the flow path of the heat medium. The positions where the flow of the heat medium branches correspond to the positions of the boundaries B1 to B4 in the longitudinal direction DL.

[0116] (4-3) Modification C

[0117] In the above embodiment, the length of each flow path region F1 to F5 in the longitudinal direction DL is preferably 10% to 50% of the distance L0. The distance L0 is the distance between the second flow hole 120b on the upper side and the second flow hole 120b on the lower side in the longitudinal direction DL. The position of the second flow hole 120b is the center of the circular shape of the second flow hole 120b. The distance L0 is the distance in the longitudinal direction DL that the heat medium flowing in from the second flow hole 120b on the upper side and flowing out from the second flow hole 120b on the lower side moves in the space between the first heat transfer plate 110 and the second heat transfer plate 120.

[0118] In this case, the distance from the branching position to the adjacent branching position in the longitudinal direction DL is preferably 10% to 50% of the distance L0 corresponding to the length of the heat medium flow path. The branching position is a position in the longitudinal direction DL where the flow of the heat medium branches.

[0119] In the modified examples A to C, the distance L0 may be the dimension of the first heat transfer plate 110 and the second heat transfer plate 120 in the longitudinal direction DL. In addition, the distance L0 may be the dimension of the second flow path 121 in the longitudinal direction DL.

[0120] (4-4) Modification D

[0121] In the above embodiment, when the value k is set to an integer satisfying 1≤k≤N-1, the number of flow paths in the k+1th flow path region is preferably 2 to 4 times the number of flow paths in the kth flow path region. In other words, whenever the flow of the heat medium branches at the boundary of two flow path regions adjacent to each other in the longitudinal direction DL, the number of flow paths of the heat medium increases by 2 to 4 times.

[0122] (4-5) Modification E

[0123] In the above-mentioned embodiment, the flow path regions F1 to F5 of the second flow path 121 have one or more flow path elements 131. The flow path element 131 corresponds to a space formed by the first rear surface 110sb of the first heat transfer plate 110 and the second front surface 120sa of the second heat transfer plate 120 facing each other. In other words, in the flow path element 131, the first heat transfer plate 110 is not in contact with the second heat transfer plate 120. However, a reinforcing member for making the first heat transfer plate 110 and the second heat transfer plate 120 in contact with each other in the flow path element 131 may be provided on at least one of the first heat transfer plate 110 and the second heat transfer plate 120. The reinforcing member is a component for ensuring the strength of the flow path element 131 of the first heat transfer plate 110 and the second heat transfer plate 120. By providing the reinforcing member, the first rear surface 110sb of the first heat transfer plate 110 and the second front surface 120sa of the second heat transfer plate 120 contact each other in the flow path element 131 , thereby suppressing a reduction in the flow path cross-sectional area of ​​the second flow path 121 .

[0124] The reinforcing member is, for example, a dot-shaped protrusion formed on at least one of the first heat transfer plate 110 and the second heat transfer plate 120. The reinforcing member has a size that does not reduce the flow velocity of the heat medium in the flow path element 131, and has a shape that does not substantially branch the flow path in the flow path element 131. In other words, the reinforcing member preferably has a size and shape that does not affect the number and cross-sectional area of ​​the flow path elements 131 in the flow path area.

[0125] (4-6) Modification F

[0126] In the above-mentioned embodiment, the heat exchanger 100 is formed in such a manner that the refrigerant flowing in the first flow path 111 and the heat medium flowing in the second flow path 121 become parallel flows. However, the heat exchanger 100 may be formed in such a manner that the refrigerant flowing in the first flow path 111 and the refrigerant flowing in the second flow path 121 become counter flows. For example, in the first flow path 111, the refrigerant may flow from the first flow hole 110b on the lower side toward the first flow hole 110b on the upper side, and in the second flow path 121, the heat medium may flow from the second flow hole 120b on the upper side toward the second flow hole 120b on the lower side.

[0127] (4-7) Modification G

[0128] In the above embodiment, the heat exchanger 100 has a branching structure in which the flow of the heat medium gradually branches in the second flow path 121, and the number of flow path elements 131 for the flow of the heat medium gradually increases. However, the heat exchanger 100 may also have a branching structure in the first flow path 111 that is the same as the second flow path 121. Specifically, in the first flow path 111, a branching structure may also be provided in which the flow of the refrigerant gradually branches, and the number of spaces (equivalent to the flow path elements 131) for the flow of the refrigerant gradually increases.

[0129] In the heat source side heat exchanger 12 of the heat source side cycle 10, the flow path for the refrigerant to flow may also have the same branching structure as the second flow path 121. In addition, in the utilization side heat exchanger 22 of the utilization side cycle 20, the flow path for the heat medium to flow may also have the same branching structure as the second flow path 121.

[0130] (4-8) Modification H

[0131] In the above-mentioned embodiment, R1234ze is exemplified as the refrigerant and carbon dioxide is exemplified as the heat medium, but the refrigerant and the heat medium are not limited thereto.

[0132] As the refrigerant, R32, HFO refrigerant, a mixed refrigerant of R32 and HFO refrigerant, carbon dioxide, ammonia, propane, etc. can also be used. As the heat medium, refrigerants such as R-32, HFO refrigerant, a mixed refrigerant of HFC-32 and HFO refrigerant, carbon dioxide, ammonia, propane, water, antifreeze, etc. can be used.

[0133] (4-9) Modification Example I

[0134] In the above embodiment, the first introduction pipe 150a, the first outlet pipe 150b, the second introduction pipe 160a, and the second outlet pipe 160b are all formed in the first frame 130. However, at least a portion of the first introduction pipe 150a, the first outlet pipe 150b, the second introduction pipe 160a, and the second outlet pipe 160b may be formed in the second frame 140.

[0135] (4) Modification J

[0136] In the above embodiment, the refrigerant cycle device 1 is a binary refrigeration device having a heat source side cycle 10 and a utilization side cycle 20. However, the refrigerant cycle device 1 may also be a refrigeration device having only one vapor compression cycle that circulates the refrigerant. For example, the refrigerant cycle device 1 may also have a refrigerant cycle composed of elements corresponding to the heat source side compressor 11, the heat source side heat exchanger 12, the heat source side expansion valve 13, and the utilization side heat exchanger 22. In this case, the heat source side heat exchanger 12 that functions as a condenser of the refrigerant may also have a branch structure similar to the second flow path 121 of the above embodiment.

[0137] As mentioned above, although the embodiment of this disclosure is described, it should be understood that various changes in form and detailed structure can be made without departing from the spirit and scope of this disclosure described in the claims.

[0138] Description of symbols

[0139] 1: Refrigerant circulation device;

[0140] 100: heat exchanger;

[0141] 110: first heat transfer plate (component);

[0142] 120: second heat transfer plate (component);

[0143] 120b: the second flow hole (first opening) on ​​the upper side;

[0144] 120b: the second flow hole (second opening) on ​​the lower side;

[0145] 131: Flow path element (flow path);

[0146] DL: length direction (first direction);

[0147] DS: stacking direction (second direction);

[0148] F1: 1st flow path area;

[0149] F2: 2nd flow path area;

[0150] F5: 5th flow path area (Nth flow path area).

[0151] Prior art literature

[0152] Patent Literature

[0153] Patent document 1: Japanese Patent Application Publication No. 2016-90157.

Claims

1. A heat exchanger (100), wherein a fluid flows in a first direction (DL) between a first opening (120b) and a second opening (120b), wherein: The heat exchanger includes a member (110, 120) having N flow path regions disposed adjacent to each other along the first direction between the first opening and the second opening, wherein N is an integer greater than or equal to 2. The N flow path regions each have a flow path (131) for the fluid to flow. The number and cross-sectional area of ​​the flow paths in the first flow path area (F1) which is the first one from the first opening side in the first direction among the N flow path areas are different from the number and cross-sectional area of ​​the flow paths in the Nth flow path area (F5) which is the Nth one from the first opening side in the first direction among the N flow path areas.

2. The heat exchanger according to claim 1, wherein: The number of flow paths in the i-th flow path region that is the i-th from the first opening side in the first direction among the N flow path regions is less than the number of flow paths in the j-th flow path region that is the j-th from the first opening side in the first direction among the N flow path regions, wherein i and j are integers satisfying 1≤i<j≤N, A cross-sectional area of ​​the flow path in the i-th flow path region is larger than a cross-sectional area of ​​the flow path in the j-th flow path region.

3. The heat exchanger according to claim 1 or 2, wherein: The number of the flow paths in the first flow path region is one.

4. The heat exchanger according to claim 3, wherein: A distance L1 in the first direction between a boundary of a second flow path region (F2) located second from the first opening in the first direction among the N flow path regions and the first flow path region and the first opening, and a distance L0 in the first direction between the first opening and the second opening satisfy: The relationship is 0.2×L0≤L1≤0.8×L0.

5. The heat exchanger according to claim 4, wherein: A distance L2 in the first direction between a boundary of two flow path regions adjacent in the first direction among the N flow path regions and the first opening, and a distance L0 in the first direction between the first opening and the second opening satisfy The relationship is 0.2×L0≤L2≤0.8×L0.

6. The heat exchanger according to any one of claims 1 to 5, wherein: The flow path branches at a boundary between a kth flow path region in the N flow path regions that is the kth from the first opening in the first direction and a k+1th flow path region in the N flow path regions that is the k+1th from the first opening in the first direction, wherein k is an integer satisfying 1≤k≤N-1, The number of the flow paths in the k+1th flow path region is 2 to 4 times the number of the flow paths in the kth flow path region.

7. The heat exchanger according to any one of claims 1 to 6, wherein: The length of each of the N flow path regions in the first direction is 10% to 50% of the distance between the first opening and the second opening in the first direction.

8. The heat exchanger according to any one of claims 1 to 7, wherein: The heat exchanger includes a plurality of the components stacked in a second direction (DS) intersecting the first direction. The N flow path regions are formed between the members adjacent to each other in the second direction.

9. The heat exchanger according to claim 8, wherein: The N flow path regions having the flow path through which the first medium as the fluid flows and the N flow path regions having the flow path through which the second medium as the fluid flows are alternately stacked in the second direction, The first medium flows in the flow path from the first opening toward the second opening. The second medium flows in the flow path from the second opening toward the first opening.

10. A refrigerant cycle device (1), wherein: The refrigeration cycle device (1) includes the heat exchanger according to any one of claims 1 to 9.

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