Heat exchanger and air conditioner provided with same

Abstract

A heat exchanger (18) includes a plurality of first and second plates (50, 52) that are in contact with each other and form a plurality of fins (46) including a first flow path (P1) through which a first fluid flows. The plurality of fins (46) are layered at intervals form between the plurality of fins a second flow path (P2) through which the second fluid (A) flows. In each of the plurality of fins (46), end surfaces (50j, 52j) on an upstream side in a flow direction of the second fluid (A) in the first and second plates (50, 52) are shifted from each other in the flow direction of the second fluid (A).

Description

TECHNICAL FIELD

[0001] The present disclosure relates to a heat exchanger and an air conditioner provided with the heat exchanger.BACKGROUND ART

[0002] Conventionally, for example, as described in JP 2021-63637 A, a plate-layered heat exchanger including a plurality of fins each formed by joining first and second plates is known. In each of the plurality of fins, a flow path through which a refrigerant flows is formed between the first and second plates. Heat exchange is performed between air flowing between the plurality of fins and the refrigerant flowing inside each of the fins.

[0003] A layered body (fin layered body) of the plurality of fins in such a plate-layered heat exchanger is produced by alternately layering first and second plates and then heating the plates while pressing the plates in a layering direction. For this purpose, each of the first and second plates is produced, for example, by press-molding a metal thin plate (brazing plate) provided with a brazing material layer on both surfaces.

[0004] JP 2022-162572 A describes a heat exchanger configured by stacking a plurality of plate fins having a pair of header channels and a heat transfer channel connecting the header channels, wherein the plate fins are configured by joining two plates, one of the two plates, a first plate, is in a flat plate state holding a strip shape, and the other second plate is a heat transfer channel forming portion that forms a heat transfer channel between itself and the first plate. Plate-like end plate portions are provided at both longitudinal ends of the heat transfer channel forming portion, wherein at least plate end edge portions of the heat transfer channel forming portion are removed.SUMMARY

[0005] Meanwhile, in the case of the plate-layered heat exchanger, since the fin is configured by two plates, the fin has a larger thickness than a fin of a fin tube heat exchanger configured by one plate. Therefore, a large water droplet is generated at an edge of the fin on an upstream side in a flow direction of the air flowing between the fins, and the water droplet may jump out to the outside of the heat exchanger.

[0006] Specifically, when the air is cooled by the heat exchanger, the moist air hits against a bulky edge on the upstream side of the fins and forms dew condensation, thereby generating large water droplets on the edge. As a result, a ventilation resistance of a gap (flow path) between the fins through which the air flows increases, and the flow velocity of the air increases. The air having the increased flow velocity blows large water droplets on the edge to the outside of the heat exchanger. In a case where the air heat-exchanged with the heat exchanger is supplied into a room, the large water droplets are blown into the room.

[0007] Therefore, an object of the present disclosure is to suppress water droplets from jumping out of a heat exchanger in a plate-layered heat exchanger.

[0008] In order to solve the above problem, according to one aspect of the present disclosure, provided is a heat exchanger as defined in claim 1 including a plurality of first and second plates that are in contact with each other and form a plurality of fins including a first flow path through which a first fluid flows, in which the plurality of fins are layered at intervals to form between the plurality of fins a second flow path through which a second fluid flows, and in each of the plurality of fins, end surfaces on an upstream side in a flow direction of the second fluid in the first and second plates are shifted from each other in the flow direction of the second fluid.

[0009] Furthermore, according to another aspect of the present disclosure, provided is an air conditioner as defined in claim 4 including: a compressor that delivers a refrigerant; a heat exchanger through which a refrigerant flows; and a fan that generates a flow of air passing through the heat exchanger, in which the heat exchanger includes a plurality of first and second plates that are in contact with each other and form a plurality of fins including a first flow path through which a refrigerant flows, the plurality of fins are layered at intervals to form between the plurality of fins a second flow path through which air flows, and in each of the plurality of fins, end surfaces on an upstream side in a flow direction of air in the first and second plates are shifted from each other in the flow direction of the air.

[0010] According to the present disclosure, in a plate-layered heat exchanger, it is possible to suppress water droplets from jumping out of the heat exchanger.BRIEF DESCRIPTION OF DRAWINGS

[0011] Fig. 1 is a schematic diagram of an air conditioner according to an embodiment of the present disclosure; Fig. 2 is a schematic cross-sectional view of an indoor unit in the air conditioner; Fig. 3 is a perspective view of a heat exchanger according to an embodiment of the present disclosure; Fig. 4 is a perspective view of a part of a fin layered body in the heat exchanger; Fig. 5 is a front view of a part of the fin layered body; Fig. 6 is a cross-sectional view of a part of the fin layered body; Fig. 7 is an upper perspective view of a fin; Fig. 8 is a lower perspective view of the fin; Fig. 9 is an upper exploded perspective view of the fin; Fig. 10A is a perspective view of a heat exchanger of a comparative example deformed in a lateral direction of the fin; Fig. 10B is a perspective view of a heat exchanger of a comparative example deformed in a longitudinal direction of the fin; Fig. 11 is a top view of a fin in the heat exchanger disposed in an example attitude; Fig. 12A is a cross-sectional view of a fin layered body in a state where water droplets are generated in the heat exchanger not according to the invention; Fig. 12B is a cross-sectional view of a fin layered body in a state where water droplets are generated in a heat exchanger according to a comparative example not according to the invention; and Fig. 13 is a cross-sectional view of a fin layered body in a state where water droplets are generated in a heat exchanger according to a different embodiment of the present disclosure. DETAILED DESCRIPTION

[0012] A heat exchanger according to an aspect of the present disclosure includes: a plurality of first and second plates that are in contact with each other and form a plurality of fins including a first flow path through which a first fluid flows, in which the plurality of fins are layered at intervals to form between the plurality of fins a second flow path through which a second fluid flows, and in each of the plurality of fins, end surfaces on an upstream side in a flow direction of the second fluid in the first and second plates are shifted from each other in the flow direction of the second fluid.

[0013] According to such an aspect, in the plate-layered heat exchanger, it is possible to suppress water droplets from jumping out of the heat exchanger.

[0014] The first plate includes a first through hole and the second plate includes a second through hole connected to the first through hole. In each of the plurality of fins, portions of inner circumferential surfaces on a downstream side in the flow direction of the second fluid in the first and second through holes are shifted from each other in the flow direction of the second fluid.

[0015] For example, the first flow path may have a meander shape as viewed in a layering direction of the plurality of fins. In this case, the first and second through holes are formed between two portions of the first flow path that face each other with an interval therebetween.

[0016] For example, the first plate and the second plate may have the same contour shape as viewed in a layering direction of the plurality of fins.

[0017] An air conditioner according to another aspect of the present disclosure includes: a compressor that delivers a refrigerant; a heat exchanger through which a refrigerant flows; and a fan that generates a flow of air passing through the heat exchanger, in which the heat exchanger includes a plurality of first and second plates that are in contact with each other and form a plurality of fins including a first flow path through which a refrigerant flows, the plurality of fins are layered at intervals to form between the plurality of fins a second flow path through which air flows, and in each of the plurality of fins, end surfaces on an upstream side in a flow direction of air in the first and second plates are shifted from each other in the flow direction of the air.

[0018] According to such another aspect, it is possible to suppress water droplets from jumping out of the heat exchanger.

[0019] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings.

[0020] Fig. 1 is a schematic diagram of an air conditioner according to an embodiment of the present disclosure. Furthermore, Fig. 2 is a schematic cross-sectional view of an indoor unit in the air conditioner.

[0021] As illustrated in Fig. 1, an air conditioner 10 according to the present embodiment includes an indoor unit 12 disposed inside a room and an outdoor unit 14 disposed outside the room.

[0022] As illustrated in Figs. 1 and 2, the indoor unit 12 includes a casing 16 installed in a room, a heat exchanger 18 that is disposed in the casing 16 and exchanges heat with indoor air, and a cross flow fan 20 that generates a flow of indoor air so that the indoor air passes through the heat exchanger 18. The casing 16 is formed with an intake port 16a that opens upward, an intake port 16b that opens forward, and a blowout port 16c that faces obliquely downward. When the cross flow fan 20 rotates, indoor air flows into the casing 16 through the intake ports 16a, 16b and passes through the heat exchanger 18. The air having passed through the heat exchanger 18 is blown out of the casing 16 through the blowout port 16c. Note that a drain pan 22 for storing moisture in the air condensed on a surface of the heat exchanger 18 is provided below the heat exchanger 18.

[0023] As illustrated in Fig. 1, the outdoor unit 14 is mounted with a heat exchanger 24 that exchanges heat with outdoor air, an axial fan 26 that generates a flow of outdoor air so that the outdoor air passes through the heat exchanger 24, and a compressor 28 that delivers a refrigerant (first fluid) passing through the heat exchangers 18, 24. The heat exchanger 18, the heat exchanger 24, and the compressor 28 are connected via a refrigerant pipe 30. An expansion valve 32 that decompresses the refrigerant and a four-way valve 34 that changes a flow direction of the refrigerant are disposed on the refrigerant pipe 30.

[0024] During a cooling operation, the refrigerant is delivered from the compressor 28, sequentially passes through the four-way valve 34, the heat exchanger 24 of the outdoor unit 14, the expansion valve 32, and the heat exchanger 18 of the indoor unit 12, and returns to the compressor 28. During a heating operation, the refrigerant is delivered from the compressor 28, sequentially passes through the four-way valve 34, the heat exchanger 18 of the indoor unit 12, the expansion valve 32, and the heat exchanger 24 of the outdoor unit 14, and returns to the compressor 28. The flow of the refrigerant during the cooling operation and the flow of the refrigerant during the heating operation are switched by the four-way valve 34. Note that, during the cooling operation, water droplets generated by dew condensation of indoor air on the surface of the heat exchanger 18 flow along the surface of the heat exchanger 18 and drop into the drain pan 22.

[0025] Fig. 3 is a perspective view of the heat exchanger according to the embodiment of the present disclosure. Furthermore, Fig. 4 is a perspective view of a part of a fin layered body in the heat exchanger. Moreover, Fig. 5 is a front view of a part of the fin layered body. Fig. 6 is a cross-sectional view of a part of the fin layered body.

[0026] Note that an X-Y-Z orthogonal coordinate system illustrated in the drawings is for facilitating understanding of the embodiment, and does not limit the embodiment. An X-axis direction indicates a lateral direction of a fin constituting a fin structure in the heat exchanger, a Y-axis direction indicates a longitudinal direction of the fin, and a Z-axis direction indicates a layering direction of the fin. Furthermore, in the drawings, a white arrow indicates a flow direction of air A (a second fluid) flowing into the heat exchanger 18. In the case of the present embodiment, the air A passing through the heat exchanger 18 flows in the X-axis direction.

[0027] As illustrated in Figs. 3 and 4, the heat exchanger 18 includes a fin layered body 40. The fin layered body 40 is disposed between the two end plates 42, 44. One end plate 42 is provided with an inflow-side connection pipe 42a that is connected to the refrigerant pipe 30 and through which the refrigerant flows in, and an outflow-side connection pipe 42b that is connected to the refrigerant pipe 30 and through which the refrigerant flows out.

[0028] As illustrated in Figs. 4 to 6, the fin layered body 40 is formed by layering a plurality of fins 46. By layering a large number of the fins 46, the heat exchanger 18 has a flat plate shape elongated in the layering direction (Z-axis direction) of the fins 46 as illustrated in Fig. 3. Note that, in the case of the present embodiment, the plurality of fins 46 are layered in the left-right direction of the indoor unit 12.

[0029] As illustrated in Fig. 6, a first flow path P1 through which the refrigerant flows is provided inside each of the plurality of fins 46.

[0030] Fig. 7 is an upper perspective view of the fin. Furthermore, Fig. 8 is a lower perspective view of the fin. Moreover, Fig. 9 is an upper exploded perspective view of the fin.

[0031] As illustrated in Fig. 9, each of the plurality of fins 46 is formed by joining a first plate 50 and a second plate 52 to each other in the layering direction (Z-axis direction) of the fin layered body 40. As illustrated in Fig. 6, the first flow path P1 is formed between the first plate 50 and the second plate 52.

[0032] In the case of the present embodiment, the first plate 50 and the second plate 52 are produced by processing, for example, pressing a metal thin plate, a so-called brazing plate, in which brazing material layers are provided on both surfaces. The brazing plate is produced, for example, by forming an aluminum-silicon alloy layer as a brazing material on both surfaces of a thin plate produced from an aluminum alloy. The first plate 50 and the second plate 52 are joined by the brazing material layer being melted once by heating and solidified again.

[0033] The first plate 50 and the second plate 52 are joined to each other to form the first flow path P1 through which the refrigerant flows. In the case of the present embodiment, a meander-shaped recess 52b is formed on an inner surface 52a of the second plate 52 facing the first plate 50. On the other hand, a convex portion 50b that covers the meander-shaped recess 52b is formed on an inner surface 50a of the first plate 50 facing the second plate 52. The recess 52b and the convex portion 50b have a meander shape as viewed in the layering direction (Z-axis direction) of the plurality of fins 46, and define the first flow path P1 through which the refrigerant flows. As a result, each of the fins 46 including the first flow path P1 therein is formed. Furthermore, in the case of the present embodiment, the first flow path P1 is formed at a central portion in the longitudinal direction (Y-axis direction) of the fin 46 as viewed in the layering direction.

[0034] Furthermore, as illustrated in Figs. 7 and 8, the first flow path P1 communicates with the inside of tubular first and second headers 46a, 46b provided at both ends in the longitudinal direction (Y-axis direction) of the fin 46. That is, the first flow path P1 is disposed between the first and second headers 46a, 46b. Furthermore, each of these first and second headers 46a, 46b is formed by joining cylindrical portions 50c, 50d of the first plate 50 and cylindrical portions 52c, 52d of the second plate 52.

[0035] The first headers 46a of the plurality of fins 46 are coupled and joined to form a first manifold 40a as illustrated in Fig. 4. The first manifold 40a is connected to the inflow-side connection pipe 42a of the end plate 42, and guides the refrigerant having passed through the inflow-side connection pipe 42a to the first flow path P1 of each of the fins 46.

[0036] Furthermore, the second headers 46b of the plurality of fins 46 are coupled and joined to form a second manifold 40b as illustrated in Fig. 4. The second manifold 40b is connected to the outflow-side connection pipe 42b of the end plate 42, and guides the refrigerant flowing out of the first flow path P1 of each of the fins 46 to the outflow-side connection pipe 42b.

[0037] Note that, in the case of the present embodiment, as illustrated in Figs. 6 to 9, first and second through holes 50e, 52e extending in the longitudinal direction (Y-axis direction) of the fin 46 are formed in the first and second plates 50, 52, respectively. The first and second through holes 50e, 52e are connected to each other, and a through-hole-shaped heat insulating portion 46c penetrating in the layering direction (Z-axis direction) of the plurality of fins 46 is formed in each of the fins 46. As illustrated in Figs. 7 and 8, the heat insulating portion 46c is formed between two portions of the first flow path P1 facing each other in the lateral direction (X-axis direction) of the fin 46, that is, facing each other with an interval in the flow direction of the air A. The heat insulating portion 46c suppresses heat transfer (heat shortcut) from the refrigerant flowing through one part of the first flow path P1 to the refrigerant flowing through the other part of the first flow path P1 through the first and second plates 50, 52.

[0038] Furthermore, as illustrated in Figs. 7 and 9, an outer surface 50f of the first plate 50 is provided with a plurality of cut-and-raised portions 50g.

[0039] Specifically, as illustrated in Fig. 7, each of the cut-and-raised portions 50g has a square bracket shape as viewed in the flow direction (X-axis direction) of the air A, and is formed by press-molding the first plate 50. Specifically, first, two parallel slits are formed, and a portion between the slits is pushed and extended to form the first cut-and-raised portion 50g on the outer surface 50f.

[0040] The cut-and-raised portion 50g of each of the fins 46 functions as a spacer that supports another adjacent fin 46 while securing a space with the another adjacent fin 46. An outer surface 52f of the second plate 52 in another adjacent fin 46 is joined to a top portion of the cut-and-raised portion 50g. As a result, as illustrated in Figs. 5 and 6, the plurality of fins 46 are layered at intervals, and a second flow path P2 through which the air A flows is formed between the two fins 46.

[0041] As illustrated in Figs. 7 and 8, a plurality of first and second rib portions 50h, 52h are provided on the outer surfaces 50f, 52f of the first and second plates 50, 52, respectively. As illustrated in Fig. 5, the plurality of first rib portions 50h protrude toward the second plate 52 in another fin 46 adjacent to one. Furthermore, the plurality of second rib portions 52h protrude toward the second plate 52 in another fin 46 adjacent to the other. The first rib portion 50h in one of the two adjacent fins 46 and the second rib portion 52h in the other fin 46 are joined to each other via their top surfaces.

[0042] Furthermore, as illustrated in Figs. 7 and 8, although the reason will be described later, the first rib portion 50h is provided in the fin 46 (first plate 50) around, that is, surrounding the first and second headers 46a, 46b (cylindrical portion 50c, 50d). Similarly, the second rib portion 52h is provided in the fin 46 (second plate 52) around, that is, surrounding the first and second headers 46a, 46b (cylindrical portion 52c, 52d). As a result, in the case of the present embodiment, the plurality of first and second rib portions 50h, 52h are provided at both ends in the longitudinal direction (Y-axis direction) of the fin 46 together with the first and second headers 46a, 46b.

[0043] By joining the first and second rib portions 50h, 52h to each other, the rigidity of the fin layered body 40 is improved. In particular, rigidity against deformation in a direction orthogonal to the layering direction (Z-axis direction) of the plurality of fins 46 is improved. In order to explain the reason, a heat exchanger of a comparative example in which the fin does not include the first and second rib portions will be described. Note that the heat exchanger of the comparative example is substantially the same as the heat exchanger 18 of the present embodiment except that the first and second rib portions are not provided.

[0044] Fig. 10A is a perspective view of a heat exchanger of a comparative example deformed in the lateral direction of the fin. Furthermore, Fig. 10B is a perspective view of the heat exchanger of the comparative example deformed in the longitudinal direction of the fin.

[0045] Fig. 10A illustrates a state where an external force F1 is applied in the lateral direction (X-axis direction) of the fin to a central portion in the layering direction (Z-axis direction) of a fin layered body 140 in a heat exchanger 118 of the comparative example in which the fin does not include the first and second rib portions. Due to this external force F1, the fin layered body 140 of the comparative example is bent and deformed in the lateral direction of the fin.

[0046] Furthermore, Fig. 10B illustrates a state where an external force F2 is applied in the longitudinal direction (Y-axis direction) of the fin to the central portion in the layering direction (Z-axis direction) of the fin layered body 140 in the heat exchanger 118 of the comparative example in which the fin does not include the first and second rib portions. Due to this external force F2, the fin layered body 140 of the comparative example is bent and deformed in the longitudinal direction of the fin.

[0047] As a matter of course, when such external forces F1, F2 increase, the fin layered body 140 may be plastically deformed and cannot return to the original shape.

[0048] In the case of the fin layered body 140 of the comparative example, each of the plurality of fins is joined to another adjacent fin via the first and second headers and the cut-and-raised portion. Therefore, when the external forces F1, F2 are applied to the fin layered body 140, each fin is likely to be greatly displaced with respect to the another adjacent fin.

[0049] On the other hand, in the case of the fin layered body 40 of the present embodiment, each of the plurality of fins 46 is joined to another adjacent fin 46 via the first and second rib portions 50h, 52h in addition to the first and second headers 46a, 46b and the cut-and-raised portion 50g. By joining the first and second rib portions 50h, 52h, the fin layered body 40 has improved rigidity as compared with the fin layered body 140 of the comparative example. Therefore, the fin layered body 40 is smaller than the fin layered body 140 of the comparative example in a deflection amount in a case where the same external forces F1, F2 are applied. That is, in the fin layered body 40 of the embodiment, a displacement amount of the fin 46 with respect to another adjacent fin 46 in a case where the external forces F1, F2 are applied is smaller than that in the fin layered body 140 of the comparative example.

[0050] In particular, in the case of the present embodiment, as illustrated in Figs. 7 and 8, the first and second rib portions 50h, 52h are provided around the first and second headers 46a, 46b provided at both ends in the longitudinal direction (Y-axis direction) of the fin 46. As a result, the fin 46 join substantially at both ends thereof to other adjacent fins 46. As a result, the fin layered body 40 has high rigidity against the external force F2 acting in the longitudinal direction (Y-axis direction) of the fin 46 as illustrated in Fig. 10B. Furthermore, the arrangement of the first and second rib portions 50h, 52h at both ends in the longitudinal direction of the fin 46 prevents the first and second rib portions 50h, 52h from interfering with the air A flowing in the lateral direction (X-axis direction) of the fin 46 along the first flow path P1 disposed at the center in the longitudinal direction.

[0051] Furthermore, in the case of the present embodiment, as illustrated in Figs. 7 and 8, the first and second rib portions 50h, 52h are configured such that a size in the lateral direction (X-axis direction) of the fin 46 is larger than a size in the longitudinal direction (Y-axis direction), whereby the rigidity is improved with respect to the external force F1 acting in the lateral direction (X-axis direction) of the fin 46 as illustrated in Fig. 10A (as compared with the case where the size in the lateral direction of the fin 46 in the first and second rib portions 50h, 52h is smaller than the size in the longitudinal direction). Furthermore, with such a shape, a ventilation resistance against the air A by the first and second rib portions 50h, 52h is reduced.

[0052] Note that, in order to reduce the ventilation resistance against the air A, it is preferable to provide a large number of relatively small first and second rib portions 50h, 52h rather than providing a small number of relatively large first and second rib portions 50h, 52h.

[0053] Furthermore, the plurality of first and second rib portions 50h, 52h are preferably provided with a gap from the first and second headers 46a, 46b. The reason will be described with reference to Fig. 11.

[0054] Fig. 11 is a top view of the fin in the heat exchanger disposed in an example attitude.

[0055] As illustrated in Fig. 11, in some cases, the heat exchanger 18 may be used in a state where the longitudinal direction (Y-axis direction) of the fin 46 substantially coincides with a vertical direction V. In such a case, when the heat exchanger 18 cools the moist air A, water droplets generated by condensation of the moist air A on the surfaces of the fins 46 move downward along the surfaces of the fins 46. That is, in the example illustrated in Fig. 11, the water droplets move toward the first header 46a located below.

[0056] At this time, when the first and second rib portions 50h, 52h are connected to the first header 46a, there is a possibility that the water droplets accumulate at corner portions formed by the first and second rib portions 50h, 52h and the first header 46a. As a result, there is a possibility that the water droplets cannot fall on the drain pan 22 located below the heat exchanger 18.

[0057] Therefore, in the present embodiment, as illustrated in Figs. 7 and 11, a gap is provided between the first and second headers 46a, 46b and the first rib portion 50h so that the water droplets generated on the surfaces of the fins 46 due to dew condensation can fall on the drain pan 22 regardless of an attitude in which the heat exchanger 18 is used. Similarly, as illustrated in Fig. 8, a gap is also provided between the first and second headers 46a, 46b and the second rib portion 52h.

[0058] Note that, in order to verify the effects of the first and second rib portions 50h, 52h, the inventor simulated deformation due to falling of the fin layered body 40 of the present embodiment and the fin layered body 140 of the comparative example. Specifically, the inventor dropped the fin layered body in the lateral direction of the fin from the same height position, and calculated the maximum displacement amount of the fin layered body in the lateral direction by simulation. As a result, the maximum displacement amount of the fin layered body 40 of the embodiment was 25.2% lower than the maximum displacement amount of the fin layered body 140 of the comparative example. From this simulation result, it is demonstrated that the rigidity of the fin layered body is improved by the first and second rib portions 50h, 52h.

[0059] Regarding the water droplets generated by dew condensation of the moist air A in the heat exchanger 18, the heat exchanger according to the present embodiment has further features.

[0060] Fig. 12A is a cross-sectional view of the fin layered body in a state where water droplets are generated in the heat exchanger. Furthermore, Fig. 12B is a cross-sectional view of the fin layered body in a state where water droplets are generated in the heat exchanger according to the comparative example.

[0061] As illustrated in Fig. 12A, depending on the attitude of the heat exchanger 18, a water droplet W may be generated at an upstream edge 46d of each of the fins 46 in the flow direction of the air A. Specifically, during the cooling operation in which the air conditioner 10 cools the air A by the heat exchanger 18, when the moist air A hits the upstream edge 46d of the fin 46 and is condensed, the water droplet W is generated on the edge 46d. The fin 46 is configured so that the water droplet W does not grow large.

[0062] Specifically, as illustrated in Figs. 6, 7, 11, and 12A, in each of the fins 46, an upstream end surface 50j of the first plate 50 and an upstream end surface 52j of the second plate 52 in the flow direction of the air A constituting the edge 46d are shifted from each other in the flow direction of the air A. In the case of the present embodiment, the upstream end surface 52j of the second plate 52 is located upstream of the upstream end surface 50j of the first plate 50 in the flow direction of the air A. Furthermore, in the case of the present embodiment, the upstream end surfaces 50j, 52j are shifted by, for example, 0.2 to 2.0 mm.

[0063] As described above, the upstream end surfaces 50j, 52j of the first and second plates 50, 52 are shifted from each other, so that the water droplet W generated at the edge 46d of the fin 46 is reduced.

[0064] In contrast, as in the fin layered body 140 of the heat exchanger 118 of the comparative example illustrated in Fig. 12B, in a case where the upstream end surfaces 150j, 152j of the first and second plates 150, 152 are not shifted, and the positions in the flow direction of the air A coincide with each other, a large water droplet W may be generated on the edge 146d of the fin 146.

[0065] Specifically, as illustrated in Fig. 12A, the edge 46d of the fin 46 hit by the moist air A is small because it is constituted only by the upstream end surface 52j of the second plate 52. Therefore, the water droplet W generated on the edge 46d cannot grow largely on the edge 46d. Eventually, without significant growth, the water droplet W is pushed away from the edge 46d by the flow of the air A and moves on the surface of the fin 46 in a downward direction toward the drain pan 22.

[0066] On the other hand, as illustrated in Fig. 12B, in the case of the comparative example, the edge 146d of the fin 146 hit by the moist air A is large because it is constituted by the upstream end surface 150j of the first plate 150 and the upstream end surface 152j of the second plate 152. Therefore, the water droplet W generated on the edge 146d continues to deprive moisture from the moist air A and greatly grows at the edge 146d.

[0067] As illustrated in Fig. 12B, when the water droplet W greatly grows, the flow velocity of the air A flowing through the second flow path P2 between the fins 146 increases. More specifically, an opening area of an inlet of the second flow path P2 is substantially reduced by the water droplet W, so that the flow velocity of the air A increases when the air A flows into the second flow path P2.

[0068] When the flow velocity of the air A flowing through the second flow path P2 increases, a greatly grown water droplet W may be blown off by the highspeed air A and jump out to the outside of the heat exchanger 118. That is, there is a case where the greatly grown water droplet W does not move toward the drain pan on the surface of the fin 146. The large water droplet W having flown out of the heat exchanger 118 may be sucked into the fan and eventually blown out into the room from the fan.

[0069] Therefore, as illustrated in Fig. 12A, the upstream end surfaces 50j, 52j of the first and second plates 50, 52 are shifted from each other so that the water droplet W generated on the edge 46d of the fin 46 does not jump out of the heat exchanger 18.

[0070] Note that, as illustrated in Fig. 6, in the case of the present embodiment, a downstream end surface 50k of the first plate 50 and a downstream end surface 52k of the second plate 52 are also shifted in the flow direction of the air A. This is because the first and second plates 50, 52 have the same contour shape as viewed in the layering direction (Z-axis direction) of the fins 46. That is, this is because the first and second plates 50, 52 are formed by press-molding material plates having the same contour shape. By making the first and second plates 50, 52 from the same material plate, the production cost of the fin layered body 40 is reduced and the production time is shortened. Furthermore, to that end, the first and second plates 50, 52 can include substantially the same heat capacity. Thereby, each of the first and second plates 50, 52 can exchange heat with the air A flowing therebetween with substantially the same heat transfer efficiency. As a result, the heat exchange rate of the heat exchanger 18 is improved.

[0071] Furthermore, the inventor has also conducted experiments in order to confirm the effect of the upstream end surfaces 50j, 52j of the first and second plates 50, 52 being shifted relative to each other. As a result of allowing the moist air to flow into the heat exchanger 18 of the present example illustrated in Fig. 12A and the heat exchanger 118 of the comparative example illustrated in Fig. 12B at a flow rate of 1 m / s, the ventilation resistance of the present embodiment was 93% of the ventilation resistance of the comparative example. This decrease in ventilation resistance indicates that no large water droplet is generated at the edge of the fin.

[0072] Note that such a water droplet W may also occur in a portion other than the upstream end surfaces 50j, 52j of the first and second plates 50, 52.

[0073] Fig. 13 is a cross-sectional view of a fin layered body in a state where water droplets are generated in a heat exchanger according to a different embodiment of the present disclosure.

[0074] As illustrated in Fig. 13, in a fin layered body 240 of a heat exchanger 218 according to the different embodiment of the present disclosure, through-hole-shaped heat insulating portions 246c of fins 246 is large in size in the flow direction (X-axis direction) of air A. Therefore, there is a possibility that a water droplet W is generated in a portion on a downstream side in the flow direction of the air A on an inner circumferential surface of each of the through-hole-shaped heat insulating portions 246c. In each of the fins 246, the portions of the inner circumferential surfaces on the downstream side in the flow direction of the air A in first and second through holes 250e, 252e are shifted from each other in the flow direction of the air A so that the water droplet W do not grow largely. As a result, a large water droplet W is not generated in the through-hole-shaped heat insulating portion 246c of the fin 246, and the large water droplet W is suppressed from jumping out to the outside of the heat exchanger 218.

[0075] According to the present embodiment as described above, in the plate-layered heat exchanger, it is possible to suppress water droplets from jumping out of the heat exchanger.

[0076] Although the present invention has been described with reference to the above-described embodiments, the present disclosure is not limited to the above-described embodiments.

[0077] For example, in the case of the above-described embodiment, the first and second plates 50, 52 are produced from a metal thin plate provided with brazing material layers on both surfaces. The brazing material layer joins the first plate 50 and the second plate 52 to each other. However, the embodiment of the present disclosure is not limited thereto. The first and second plates may be produced from a metal thin plate provided with no brazing material layer on both sides, so long as the first and second plates can be in contact with each other and maintain the contact state.

[0078] Moreover, the heat exchanger of the above-described embodiment is provided in an air conditioner that performs indoor air conditioning. However, the embodiment of the present disclosure is not limited thereto. The heat exchanger according to the embodiment of the present disclosure can be used in a device that needs to perform heat exchange between a first fluid and a second fluid.

[0079] The present disclosure is applicable to a heat exchanger that performs heat exchange between a first fluid and a second fluid.

Examples

Embodiment Construction

[0012]A heat exchanger according to an aspect of the present disclosure includes: a plurality of first and second plates that are in contact with each other and form a plurality of fins including a first flow path through which a first fluid flows, in which the plurality of fins are layered at intervals to form between the plurality of fins a second flow path through which a second fluid flows, and in each of the plurality of fins, end surfaces on an upstream side in a flow direction of the second fluid in the first and second plates are shifted from each other in the flow direction of the second fluid.

[0013]According to such an aspect, in the plate-layered heat exchanger, it is possible to suppress water droplets from jumping out of the heat exchanger.

[0014]The first plate includes a first through hole and the second plate includes a second through hole connected to the first through hole. In each of the plurality of fins, portions of inner circumferential surfaces on a downstream ...

TECHNICAL FIELD

[0001] The present disclosure relates to a heat exchanger and an air conditioner provided with the heat exchanger.BACKGROUND ART

[0002] Conventionally, for example, as described in JP 2021-63637 A, a plate-layered heat exchanger including a plurality of fins each formed by joining first and second plates is known. In each of the plurality of fins, a flow path through which a refrigerant flows is formed between the first and second plates. Heat exchange is performed between air flowing between the plurality of fins and the refrigerant flowing inside each of the fins.

[0003] A layered body (fin layered body) of the plurality of fins in such a plate-layered heat exchanger is produced by alternately layering first and second plates and then heating the plates while pressing the plates in a layering direction. For this purpose, each of the first and second plates is produced, for example, by press-molding a metal thin plate (brazing plate) provided with a brazing material layer on both surfaces.

[0004] JP 2022-162572 A describes a heat exchanger configured by stacking a plurality of plate fins having a pair of header channels and a heat transfer channel connecting the header channels, wherein the plate fins are configured by joining two plates, one of the two plates, a first plate, is in a flat plate state holding a strip shape, and the other second plate is a heat transfer channel forming portion that forms a heat transfer channel between itself and the first plate. Plate-like end plate portions are provided at both longitudinal ends of the heat transfer channel forming portion, wherein at least plate end edge portions of the heat transfer channel forming portion are removed.SUMMARY

[0005] Meanwhile, in the case of the plate-layered heat exchanger, since the fin is configured by two plates, the fin has a larger thickness than a fin of a fin tube heat exchanger configured by one plate. Therefore, a large water droplet is generated at an edge of the fin on an upstream side in a flow direction of the air flowing between the fins, and the water droplet may jump out to the outside of the heat exchanger.

[0006] Specifically, when the air is cooled by the heat exchanger, the moist air hits against a bulky edge on the upstream side of the fins and forms dew condensation, thereby generating large water droplets on the edge. As a result, a ventilation resistance of a gap (flow path) between the fins through which the air flows increases, and the flow velocity of the air increases. The air having the increased flow velocity blows large water droplets on the edge to the outside of the heat exchanger. In a case where the air heat-exchanged with the heat exchanger is supplied into a room, the large water droplets are blown into the room.

[0007] Therefore, an object of the present disclosure is to suppress water droplets from jumping out of a heat exchanger in a plate-layered heat exchanger.

[0008] In order to solve the above problem, according to one aspect of the present disclosure, provided is a heat exchanger as defined in claim 1 including a plurality of first and second plates that are in contact with each other and form a plurality of fins including a first flow path through which a first fluid flows, in which the plurality of fins are layered at intervals to form between the plurality of fins a second flow path through which a second fluid flows, and in each of the plurality of fins, end surfaces on an upstream side in a flow direction of the second fluid in the first and second plates are shifted from each other in the flow direction of the second fluid.

[0009] Furthermore, according to another aspect of the present disclosure, provided is an air conditioner as defined in claim 4 including: a compressor that delivers a refrigerant; a heat exchanger through which a refrigerant flows; and a fan that generates a flow of air passing through the heat exchanger, in which the heat exchanger includes a plurality of first and second plates that are in contact with each other and form a plurality of fins including a first flow path through which a refrigerant flows, the plurality of fins are layered at intervals to form between the plurality of fins a second flow path through which air flows, and in each of the plurality of fins, end surfaces on an upstream side in a flow direction of air in the first and second plates are shifted from each other in the flow direction of the air.

[0010] According to the present disclosure, in a plate-layered heat exchanger, it is possible to suppress water droplets from jumping out of the heat exchanger.BRIEF DESCRIPTION OF DRAWINGS

[0011] Fig. 1 is a schematic diagram of an air conditioner according to an embodiment of the present disclosure; Fig. 2 is a schematic cross-sectional view of an indoor unit in the air conditioner; Fig. 3 is a perspective view of a heat exchanger according to an embodiment of the present disclosure; Fig. 4 is a perspective view of a part of a fin layered body in the heat exchanger; Fig. 5 is a front view of a part of the fin layered body; Fig. 6 is a cross-sectional view of a part of the fin layered body; Fig. 7 is an upper perspective view of a fin; Fig. 8 is a lower perspective view of the fin; Fig. 9 is an upper exploded perspective view of the fin; Fig. 10A is a perspective view of a heat exchanger of a comparative example deformed in a lateral direction of the fin; Fig. 10B is a perspective view of a heat exchanger of a comparative example deformed in a longitudinal direction of the fin; Fig. 11 is a top view of a fin in the heat exchanger disposed in an example attitude; Fig. 12A is a cross-sectional view of a fin layered body in a state where water droplets are generated in the heat exchanger not according to the invention; Fig. 12B is a cross-sectional view of a fin layered body in a state where water droplets are generated in a heat exchanger according to a comparative example not according to the invention; and Fig. 13 is a cross-sectional view of a fin layered body in a state where water droplets are generated in a heat exchanger according to a different embodiment of the present disclosure. DETAILED DESCRIPTION

[0012] A heat exchanger according to an aspect of the present disclosure includes: a plurality of first and second plates that are in contact with each other and form a plurality of fins including a first flow path through which a first fluid flows, in which the plurality of fins are layered at intervals to form between the plurality of fins a second flow path through which a second fluid flows, and in each of the plurality of fins, end surfaces on an upstream side in a flow direction of the second fluid in the first and second plates are shifted from each other in the flow direction of the second fluid.

[0013] According to such an aspect, in the plate-layered heat exchanger, it is possible to suppress water droplets from jumping out of the heat exchanger.

[0014] The first plate includes a first through hole and the second plate includes a second through hole connected to the first through hole. In each of the plurality of fins, portions of inner circumferential surfaces on a downstream side in the flow direction of the second fluid in the first and second through holes are shifted from each other in the flow direction of the second fluid.

[0015] For example, the first flow path may have a meander shape as viewed in a layering direction of the plurality of fins. In this case, the first and second through holes are formed between two portions of the first flow path that face each other with an interval therebetween.

[0016] For example, the first plate and the second plate may have the same contour shape as viewed in a layering direction of the plurality of fins.

[0017] An air conditioner according to another aspect of the present disclosure includes: a compressor that delivers a refrigerant; a heat exchanger through which a refrigerant flows; and a fan that generates a flow of air passing through the heat exchanger, in which the heat exchanger includes a plurality of first and second plates that are in contact with each other and form a plurality of fins including a first flow path through which a refrigerant flows, the plurality of fins are layered at intervals to form between the plurality of fins a second flow path through which air flows, and in each of the plurality of fins, end surfaces on an upstream side in a flow direction of air in the first and second plates are shifted from each other in the flow direction of the air.

[0018] According to such another aspect, it is possible to suppress water droplets from jumping out of the heat exchanger.

[0019] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings.

[0020] Fig. 1 is a schematic diagram of an air conditioner according to an embodiment of the present disclosure. Furthermore, Fig. 2 is a schematic cross-sectional view of an indoor unit in the air conditioner.

[0021] As illustrated in Fig. 1, an air conditioner 10 according to the present embodiment includes an indoor unit 12 disposed inside a room and an outdoor unit 14 disposed outside the room.

[0022] As illustrated in Figs. 1 and 2, the indoor unit 12 includes a casing 16 installed in a room, a heat exchanger 18 that is disposed in the casing 16 and exchanges heat with indoor air, and a cross flow fan 20 that generates a flow of indoor air so that the indoor air passes through the heat exchanger 18. The casing 16 is formed with an intake port 16a that opens upward, an intake port 16b that opens forward, and a blowout port 16c that faces obliquely downward. When the cross flow fan 20 rotates, indoor air flows into the casing 16 through the intake ports 16a, 16b and passes through the heat exchanger 18. The air having passed through the heat exchanger 18 is blown out of the casing 16 through the blowout port 16c. Note that a drain pan 22 for storing moisture in the air condensed on a surface of the heat exchanger 18 is provided below the heat exchanger 18.

[0023] As illustrated in Fig. 1, the outdoor unit 14 is mounted with a heat exchanger 24 that exchanges heat with outdoor air, an axial fan 26 that generates a flow of outdoor air so that the outdoor air passes through the heat exchanger 24, and a compressor 28 that delivers a refrigerant (first fluid) passing through the heat exchangers 18, 24. The heat exchanger 18, the heat exchanger 24, and the compressor 28 are connected via a refrigerant pipe 30. An expansion valve 32 that decompresses the refrigerant and a four-way valve 34 that changes a flow direction of the refrigerant are disposed on the refrigerant pipe 30.

[0024] During a cooling operation, the refrigerant is delivered from the compressor 28, sequentially passes through the four-way valve 34, the heat exchanger 24 of the outdoor unit 14, the expansion valve 32, and the heat exchanger 18 of the indoor unit 12, and returns to the compressor 28. During a heating operation, the refrigerant is delivered from the compressor 28, sequentially passes through the four-way valve 34, the heat exchanger 18 of the indoor unit 12, the expansion valve 32, and the heat exchanger 24 of the outdoor unit 14, and returns to the compressor 28. The flow of the refrigerant during the cooling operation and the flow of the refrigerant during the heating operation are switched by the four-way valve 34. Note that, during the cooling operation, water droplets generated by dew condensation of indoor air on the surface of the heat exchanger 18 flow along the surface of the heat exchanger 18 and drop into the drain pan 22.

[0025] Fig. 3 is a perspective view of the heat exchanger according to the embodiment of the present disclosure. Furthermore, Fig. 4 is a perspective view of a part of a fin layered body in the heat exchanger. Moreover, Fig. 5 is a front view of a part of the fin layered body. Fig. 6 is a cross-sectional view of a part of the fin layered body.

[0026] Note that an X-Y-Z orthogonal coordinate system illustrated in the drawings is for facilitating understanding of the embodiment, and does not limit the embodiment. An X-axis direction indicates a lateral direction of a fin constituting a fin structure in the heat exchanger, a Y-axis direction indicates a longitudinal direction of the fin, and a Z-axis direction indicates a layering direction of the fin. Furthermore, in the drawings, a white arrow indicates a flow direction of air A (a second fluid) flowing into the heat exchanger 18. In the case of the present embodiment, the air A passing through the heat exchanger 18 flows in the X-axis direction.

[0027] As illustrated in Figs. 3 and 4, the heat exchanger 18 includes a fin layered body 40. The fin layered body 40 is disposed between the two end plates 42, 44. One end plate 42 is provided with an inflow-side connection pipe 42a that is connected to the refrigerant pipe 30 and through which the refrigerant flows in, and an outflow-side connection pipe 42b that is connected to the refrigerant pipe 30 and through which the refrigerant flows out.

[0028] As illustrated in Figs. 4 to 6, the fin layered body 40 is formed by layering a plurality of fins 46. By layering a large number of the fins 46, the heat exchanger 18 has a flat plate shape elongated in the layering direction (Z-axis direction) of the fins 46 as illustrated in Fig. 3. Note that, in the case of the present embodiment, the plurality of fins 46 are layered in the left-right direction of the indoor unit 12.

[0029] As illustrated in Fig. 6, a first flow path P1 through which the refrigerant flows is provided inside each of the plurality of fins 46.

[0030] Fig. 7 is an upper perspective view of the fin. Furthermore, Fig. 8 is a lower perspective view of the fin. Moreover, Fig. 9 is an upper exploded perspective view of the fin.

[0031] As illustrated in Fig. 9, each of the plurality of fins 46 is formed by joining a first plate 50 and a second plate 52 to each other in the layering direction (Z-axis direction) of the fin layered body 40. As illustrated in Fig. 6, the first flow path P1 is formed between the first plate 50 and the second plate 52.

[0032] In the case of the present embodiment, the first plate 50 and the second plate 52 are produced by processing, for example, pressing a metal thin plate, a so-called brazing plate, in which brazing material layers are provided on both surfaces. The brazing plate is produced, for example, by forming an aluminum-silicon alloy layer as a brazing material on both surfaces of a thin plate produced from an aluminum alloy. The first plate 50 and the second plate 52 are joined by the brazing material layer being melted once by heating and solidified again.

[0033] The first plate 50 and the second plate 52 are joined to each other to form the first flow path P1 through which the refrigerant flows. In the case of the present embodiment, a meander-shaped recess 52b is formed on an inner surface 52a of the second plate 52 facing the first plate 50. On the other hand, a convex portion 50b that covers the meander-shaped recess 52b is formed on an inner surface 50a of the first plate 50 facing the second plate 52. The recess 52b and the convex portion 50b have a meander shape as viewed in the layering direction (Z-axis direction) of the plurality of fins 46, and define the first flow path P1 through which the refrigerant flows. As a result, each of the fins 46 including the first flow path P1 therein is formed. Furthermore, in the case of the present embodiment, the first flow path P1 is formed at a central portion in the longitudinal direction (Y-axis direction) of the fin 46 as viewed in the layering direction.

[0034] Furthermore, as illustrated in Figs. 7 and 8, the first flow path P1 communicates with the inside of tubular first and second headers 46a, 46b provided at both ends in the longitudinal direction (Y-axis direction) of the fin 46. That is, the first flow path P1 is disposed between the first and second headers 46a, 46b. Furthermore, each of these first and second headers 46a, 46b is formed by joining cylindrical portions 50c, 50d of the first plate 50 and cylindrical portions 52c, 52d of the second plate 52.

[0035] The first headers 46a of the plurality of fins 46 are coupled and joined to form a first manifold 40a as illustrated in Fig. 4. The first manifold 40a is connected to the inflow-side connection pipe 42a of the end plate 42, and guides the refrigerant having passed through the inflow-side connection pipe 42a to the first flow path P1 of each of the fins 46.

[0036] Furthermore, the second headers 46b of the plurality of fins 46 are coupled and joined to form a second manifold 40b as illustrated in Fig. 4. The second manifold 40b is connected to the outflow-side connection pipe 42b of the end plate 42, and guides the refrigerant flowing out of the first flow path P1 of each of the fins 46 to the outflow-side connection pipe 42b.

[0037] Note that, in the case of the present embodiment, as illustrated in Figs. 6 to 9, first and second through holes 50e, 52e extending in the longitudinal direction (Y-axis direction) of the fin 46 are formed in the first and second plates 50, 52, respectively. The first and second through holes 50e, 52e are connected to each other, and a through-hole-shaped heat insulating portion 46c penetrating in the layering direction (Z-axis direction) of the plurality of fins 46 is formed in each of the fins 46. As illustrated in Figs. 7 and 8, the heat insulating portion 46c is formed between two portions of the first flow path P1 facing each other in the lateral direction (X-axis direction) of the fin 46, that is, facing each other with an interval in the flow direction of the air A. The heat insulating portion 46c suppresses heat transfer (heat shortcut) from the refrigerant flowing through one part of the first flow path P1 to the refrigerant flowing through the other part of the first flow path P1 through the first and second plates 50, 52.

[0038] Furthermore, as illustrated in Figs. 7 and 9, an outer surface 50f of the first plate 50 is provided with a plurality of cut-and-raised portions 50g.

[0039] Specifically, as illustrated in Fig. 7, each of the cut-and-raised portions 50g has a square bracket shape as viewed in the flow direction (X-axis direction) of the air A, and is formed by press-molding the first plate 50. Specifically, first, two parallel slits are formed, and a portion between the slits is pushed and extended to form the first cut-and-raised portion 50g on the outer surface 50f.

[0040] The cut-and-raised portion 50g of each of the fins 46 functions as a spacer that supports another adjacent fin 46 while securing a space with the another adjacent fin 46. An outer surface 52f of the second plate 52 in another adjacent fin 46 is joined to a top portion of the cut-and-raised portion 50g. As a result, as illustrated in Figs. 5 and 6, the plurality of fins 46 are layered at intervals, and a second flow path P2 through which the air A flows is formed between the two fins 46.

[0041] As illustrated in Figs. 7 and 8, a plurality of first and second rib portions 50h, 52h are provided on the outer surfaces 50f, 52f of the first and second plates 50, 52, respectively. As illustrated in Fig. 5, the plurality of first rib portions 50h protrude toward the second plate 52 in another fin 46 adjacent to one. Furthermore, the plurality of second rib portions 52h protrude toward the second plate 52 in another fin 46 adjacent to the other. The first rib portion 50h in one of the two adjacent fins 46 and the second rib portion 52h in the other fin 46 are joined to each other via their top surfaces.

[0042] Furthermore, as illustrated in Figs. 7 and 8, although the reason will be described later, the first rib portion 50h is provided in the fin 46 (first plate 50) around, that is, surrounding the first and second headers 46a, 46b (cylindrical portion 50c, 50d). Similarly, the second rib portion 52h is provided in the fin 46 (second plate 52) around, that is, surrounding the first and second headers 46a, 46b (cylindrical portion 52c, 52d). As a result, in the case of the present embodiment, the plurality of first and second rib portions 50h, 52h are provided at both ends in the longitudinal direction (Y-axis direction) of the fin 46 together with the first and second headers 46a, 46b.

[0043] By joining the first and second rib portions 50h, 52h to each other, the rigidity of the fin layered body 40 is improved. In particular, rigidity against deformation in a direction orthogonal to the layering direction (Z-axis direction) of the plurality of fins 46 is improved. In order to explain the reason, a heat exchanger of a comparative example in which the fin does not include the first and second rib portions will be described. Note that the heat exchanger of the comparative example is substantially the same as the heat exchanger 18 of the present embodiment except that the first and second rib portions are not provided.

[0044] Fig. 10A is a perspective view of a heat exchanger of a comparative example deformed in the lateral direction of the fin. Furthermore, Fig. 10B is a perspective view of the heat exchanger of the comparative example deformed in the longitudinal direction of the fin.

[0045] Fig. 10A illustrates a state where an external force F1 is applied in the lateral direction (X-axis direction) of the fin to a central portion in the layering direction (Z-axis direction) of a fin layered body 140 in a heat exchanger 118 of the comparative example in which the fin does not include the first and second rib portions. Due to this external force F1, the fin layered body 140 of the comparative example is bent and deformed in the lateral direction of the fin.

[0046] Furthermore, Fig. 10B illustrates a state where an external force F2 is applied in the longitudinal direction (Y-axis direction) of the fin to the central portion in the layering direction (Z-axis direction) of the fin layered body 140 in the heat exchanger 118 of the comparative example in which the fin does not include the first and second rib portions. Due to this external force F2, the fin layered body 140 of the comparative example is bent and deformed in the longitudinal direction of the fin.

[0047] As a matter of course, when such external forces F1, F2 increase, the fin layered body 140 may be plastically deformed and cannot return to the original shape.

[0048] In the case of the fin layered body 140 of the comparative example, each of the plurality of fins is joined to another adjacent fin via the first and second headers and the cut-and-raised portion. Therefore, when the external forces F1, F2 are applied to the fin layered body 140, each fin is likely to be greatly displaced with respect to the another adjacent fin.

[0049] On the other hand, in the case of the fin layered body 40 of the present embodiment, each of the plurality of fins 46 is joined to another adjacent fin 46 via the first and second rib portions 50h, 52h in addition to the first and second headers 46a, 46b and the cut-and-raised portion 50g. By joining the first and second rib portions 50h, 52h, the fin layered body 40 has improved rigidity as compared with the fin layered body 140 of the comparative example. Therefore, the fin layered body 40 is smaller than the fin layered body 140 of the comparative example in a deflection amount in a case where the same external forces F1, F2 are applied. That is, in the fin layered body 40 of the embodiment, a displacement amount of the fin 46 with respect to another adjacent fin 46 in a case where the external forces F1, F2 are applied is smaller than that in the fin layered body 140 of the comparative example.

[0050] In particular, in the case of the present embodiment, as illustrated in Figs. 7 and 8, the first and second rib portions 50h, 52h are provided around the first and second headers 46a, 46b provided at both ends in the longitudinal direction (Y-axis direction) of the fin 46. As a result, the fin 46 join substantially at both ends thereof to other adjacent fins 46. As a result, the fin layered body 40 has high rigidity against the external force F2 acting in the longitudinal direction (Y-axis direction) of the fin 46 as illustrated in Fig. 10B. Furthermore, the arrangement of the first and second rib portions 50h, 52h at both ends in the longitudinal direction of the fin 46 prevents the first and second rib portions 50h, 52h from interfering with the air A flowing in the lateral direction (X-axis direction) of the fin 46 along the first flow path P1 disposed at the center in the longitudinal direction.

[0051] Furthermore, in the case of the present embodiment, as illustrated in Figs. 7 and 8, the first and second rib portions 50h, 52h are configured such that a size in the lateral direction (X-axis direction) of the fin 46 is larger than a size in the longitudinal direction (Y-axis direction), whereby the rigidity is improved with respect to the external force F1 acting in the lateral direction (X-axis direction) of the fin 46 as illustrated in Fig. 10A (as compared with the case where the size in the lateral direction of the fin 46 in the first and second rib portions 50h, 52h is smaller than the size in the longitudinal direction). Furthermore, with such a shape, a ventilation resistance against the air A by the first and second rib portions 50h, 52h is reduced.

[0052] Note that, in order to reduce the ventilation resistance against the air A, it is preferable to provide a large number of relatively small first and second rib portions 50h, 52h rather than providing a small number of relatively large first and second rib portions 50h, 52h.

[0053] Furthermore, the plurality of first and second rib portions 50h, 52h are preferably provided with a gap from the first and second headers 46a, 46b. The reason will be described with reference to Fig. 11.

[0054] Fig. 11 is a top view of the fin in the heat exchanger disposed in an example attitude.

[0055] As illustrated in Fig. 11, in some cases, the heat exchanger 18 may be used in a state where the longitudinal direction (Y-axis direction) of the fin 46 substantially coincides with a vertical direction V. In such a case, when the heat exchanger 18 cools the moist air A, water droplets generated by condensation of the moist air A on the surfaces of the fins 46 move downward along the surfaces of the fins 46. That is, in the example illustrated in Fig. 11, the water droplets move toward the first header 46a located below.

[0056] At this time, when the first and second rib portions 50h, 52h are connected to the first header 46a, there is a possibility that the water droplets accumulate at corner portions formed by the first and second rib portions 50h, 52h and the first header 46a. As a result, there is a possibility that the water droplets cannot fall on the drain pan 22 located below the heat exchanger 18.

[0057] Therefore, in the present embodiment, as illustrated in Figs. 7 and 11, a gap is provided between the first and second headers 46a, 46b and the first rib portion 50h so that the water droplets generated on the surfaces of the fins 46 due to dew condensation can fall on the drain pan 22 regardless of an attitude in which the heat exchanger 18 is used. Similarly, as illustrated in Fig. 8, a gap is also provided between the first and second headers 46a, 46b and the second rib portion 52h.

[0058] Note that, in order to verify the effects of the first and second rib portions 50h, 52h, the inventor simulated deformation due to falling of the fin layered body 40 of the present embodiment and the fin layered body 140 of the comparative example. Specifically, the inventor dropped the fin layered body in the lateral direction of the fin from the same height position, and calculated the maximum displacement amount of the fin layered body in the lateral direction by simulation. As a result, the maximum displacement amount of the fin layered body 40 of the embodiment was 25.2% lower than the maximum displacement amount of the fin layered body 140 of the comparative example. From this simulation result, it is demonstrated that the rigidity of the fin layered body is improved by the first and second rib portions 50h, 52h.

[0059] Regarding the water droplets generated by dew condensation of the moist air A in the heat exchanger 18, the heat exchanger according to the present embodiment has further features.

[0060] Fig. 12A is a cross-sectional view of the fin layered body in a state where water droplets are generated in the heat exchanger. Furthermore, Fig. 12B is a cross-sectional view of the fin layered body in a state where water droplets are generated in the heat exchanger according to the comparative example.

[0061] As illustrated in Fig. 12A, depending on the attitude of the heat exchanger 18, a water droplet W may be generated at an upstream edge 46d of each of the fins 46 in the flow direction of the air A. Specifically, during the cooling operation in which the air conditioner 10 cools the air A by the heat exchanger 18, when the moist air A hits the upstream edge 46d of the fin 46 and is condensed, the water droplet W is generated on the edge 46d. The fin 46 is configured so that the water droplet W does not grow large.

[0062] Specifically, as illustrated in Figs. 6, 7, 11, and 12A, in each of the fins 46, an upstream end surface 50j of the first plate 50 and an upstream end surface 52j of the second plate 52 in the flow direction of the air A constituting the edge 46d are shifted from each other in the flow direction of the air A. In the case of the present embodiment, the upstream end surface 52j of the second plate 52 is located upstream of the upstream end surface 50j of the first plate 50 in the flow direction of the air A. Furthermore, in the case of the present embodiment, the upstream end surfaces 50j, 52j are shifted by, for example, 0.2 to 2.0 mm.

[0063] As described above, the upstream end surfaces 50j, 52j of the first and second plates 50, 52 are shifted from each other, so that the water droplet W generated at the edge 46d of the fin 46 is reduced.

[0064] In contrast, as in the fin layered body 140 of the heat exchanger 118 of the comparative example illustrated in Fig. 12B, in a case where the upstream end surfaces 150j, 152j of the first and second plates 150, 152 are not shifted, and the positions in the flow direction of the air A coincide with each other, a large water droplet W may be generated on the edge 146d of the fin 146.

[0065] Specifically, as illustrated in Fig. 12A, the edge 46d of the fin 46 hit by the moist air A is small because it is constituted only by the upstream end surface 52j of the second plate 52. Therefore, the water droplet W generated on the edge 46d cannot grow largely on the edge 46d. Eventually, without significant growth, the water droplet W is pushed away from the edge 46d by the flow of the air A and moves on the surface of the fin 46 in a downward direction toward the drain pan 22.

[0066] On the other hand, as illustrated in Fig. 12B, in the case of the comparative example, the edge 146d of the fin 146 hit by the moist air A is large because it is constituted by the upstream end surface 150j of the first plate 150 and the upstream end surface 152j of the second plate 152. Therefore, the water droplet W generated on the edge 146d continues to deprive moisture from the moist air A and greatly grows at the edge 146d.

[0067] As illustrated in Fig. 12B, when the water droplet W greatly grows, the flow velocity of the air A flowing through the second flow path P2 between the fins 146 increases. More specifically, an opening area of an inlet of the second flow path P2 is substantially reduced by the water droplet W, so that the flow velocity of the air A increases when the air A flows into the second flow path P2.

[0068] When the flow velocity of the air A flowing through the second flow path P2 increases, a greatly grown water droplet W may be blown off by the highspeed air A and jump out to the outside of the heat exchanger 118. That is, there is a case where the greatly grown water droplet W does not move toward the drain pan on the surface of the fin 146. The large water droplet W having flown out of the heat exchanger 118 may be sucked into the fan and eventually blown out into the room from the fan.

[0069] Therefore, as illustrated in Fig. 12A, the upstream end surfaces 50j, 52j of the first and second plates 50, 52 are shifted from each other so that the water droplet W generated on the edge 46d of the fin 46 does not jump out of the heat exchanger 18.

[0070] Note that, as illustrated in Fig. 6, in the case of the present embodiment, a downstream end surface 50k of the first plate 50 and a downstream end surface 52k of the second plate 52 are also shifted in the flow direction of the air A. This is because the first and second plates 50, 52 have the same contour shape as viewed in the layering direction (Z-axis direction) of the fins 46. That is, this is because the first and second plates 50, 52 are formed by press-molding material plates having the same contour shape. By making the first and second plates 50, 52 from the same material plate, the production cost of the fin layered body 40 is reduced and the production time is shortened. Furthermore, to that end, the first and second plates 50, 52 can include substantially the same heat capacity. Thereby, each of the first and second plates 50, 52 can exchange heat with the air A flowing therebetween with substantially the same heat transfer efficiency. As a result, the heat exchange rate of the heat exchanger 18 is improved.

[0071] Furthermore, the inventor has also conducted experiments in order to confirm the effect of the upstream end surfaces 50j, 52j of the first and second plates 50, 52 being shifted relative to each other. As a result of allowing the moist air to flow into the heat exchanger 18 of the present example illustrated in Fig. 12A and the heat exchanger 118 of the comparative example illustrated in Fig. 12B at a flow rate of 1 m / s, the ventilation resistance of the present embodiment was 93% of the ventilation resistance of the comparative example. This decrease in ventilation resistance indicates that no large water droplet is generated at the edge of the fin.

[0072] Note that such a water droplet W may also occur in a portion other than the upstream end surfaces 50j, 52j of the first and second plates 50, 52.

[0073] Fig. 13 is a cross-sectional view of a fin layered body in a state where water droplets are generated in a heat exchanger according to a different embodiment of the present disclosure.

[0074] As illustrated in Fig. 13, in a fin layered body 240 of a heat exchanger 218 according to the different embodiment of the present disclosure, through-hole-shaped heat insulating portions 246c of fins 246 is large in size in the flow direction (X-axis direction) of air A. Therefore, there is a possibility that a water droplet W is generated in a portion on a downstream side in the flow direction of the air A on an inner circumferential surface of each of the through-hole-shaped heat insulating portions 246c. In each of the fins 246, the portions of the inner circumferential surfaces on the downstream side in the flow direction of the air A in first and second through holes 250e, 252e are shifted from each other in the flow direction of the air A so that the water droplet W do not grow largely. As a result, a large water droplet W is not generated in the through-hole-shaped heat insulating portion 246c of the fin 246, and the large water droplet W is suppressed from jumping out to the outside of the heat exchanger 218.

[0075] According to the present embodiment as described above, in the plate-layered heat exchanger, it is possible to suppress water droplets from jumping out of the heat exchanger.

[0076] Although the present invention has been described with reference to the above-described embodiments, the present disclosure is not limited to the above-described embodiments.

[0077] For example, in the case of the above-described embodiment, the first and second plates 50, 52 are produced from a metal thin plate provided with brazing material layers on both surfaces. The brazing material layer joins the first plate 50 and the second plate 52 to each other. However, the embodiment of the present disclosure is not limited thereto. The first and second plates may be produced from a metal thin plate provided with no brazing material layer on both sides, so long as the first and second plates can be in contact with each other and maintain the contact state.

[0078] Moreover, the heat exchanger of the above-described embodiment is provided in an air conditioner that performs indoor air conditioning. However, the embodiment of the present disclosure is not limited thereto. The heat exchanger according to the embodiment of the present disclosure can be used in a device that needs to perform heat exchange between a first fluid and a second fluid.

[0079] The present disclosure is applicable to a heat exchanger that performs heat exchange between a first fluid and a second fluid.

Examples

Embodiment Construction

[0012]A heat exchanger according to an aspect of the present disclosure includes: a plurality of first and second plates that are in contact with each other and form a plurality of fins including a first flow path through which a first fluid flows, in which the plurality of fins are layered at intervals to form between the plurality of fins a second flow path through which a second fluid flows, and in each of the plurality of fins, end surfaces on an upstream side in a flow direction of the second fluid in the first and second plates are shifted from each other in the flow direction of the second fluid.

[0013]According to such an aspect, in the plate-layered heat exchanger, it is possible to suppress water droplets from jumping out of the heat exchanger.

[0014]The first plate includes a first through hole and the second plate includes a second through hole connected to the first through hole. In each of the plurality of fins, portions of inner circumferential surfaces on a downstream ...

Claims

1. A heat exchanger (18) comprising a plurality of first and second plates (50, 52) that are in contact with each other and form a plurality of fins (46) including a first flow path (P1) through which a first fluid flows, wherein the plurality of fins (469) are layered at intervals to form between the plurality of fins (46) a second flow path (P2) through which a second fluid flows, and in each of the plurality of fins (46), end surfaces (50j) on an upstream side in a flow direction of the second fluid in the first and second plates (50, 52) are shifted from each other in the flow direction of the second fluid, wherein the first plate (50) includes a first through hole (50e), and the second plate (52) includes a second through hole (52e) connected to the first through hole (50e), characterized in that in each of the plurality of fins (46), portions of inner circumferential surfaces on a downstream side in the flow direction of the second fluid in the first and second through holes (50e, 52e) are shifted from each other in the flow direction of the second fluid.

2. The heat exchanger (18) according to claim 1, wherein the first flow path (P1) has a meander shape as viewed in a layering direction of the plurality of fins (46), and the first and second through holes (50, 52) are formed between two portions of the first flow path (P1), the two portions facing each other with an interval.

3. The heat exchanger (18) according to claim 1, wherein the first plate (50) and the second plate (52) have the same contour shape as viewed in a layering direction of the plurality of fins (46).

4. An air conditioner (10) comprising: a compressor (28) that delivers a refrigerant; a heat exchanger (18) according to any of claims 1 to 3; and a fan that generates a flow of air passing through the heat exchanger, wherein the first fluid is a refrigerant and the second fluid is air.

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