Plate-fin stacked heat exchanger and refrigeration system using same

Abstract

To provide a plate fin lamination type heat exchanger that is lightweight and has high reliability and high performance, and a refrigeration system using the same.SOLUTION: A plate fin lamination type heat exchanger according to the present disclosure is a heat exchanger constituted by laminating a plurality of plate fins 2a, and has a shape in which the plate fins 2a each comprise a header region part 11 and a flow passage region part 12, the header region part 11 is constituted by joining two plates 16a and 16b each comprising a header flow passage opening, the flow passage region part 12 is constituted of one flow passage plate 18 in which a heat transfer passage 8 is extruded, and the plate fins 2a are each constituted by integrally joining the header region part 11 and the flow passage region part 12.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to a plate fin stack type heat exchanger and a refrigeration system using the same. [Background technology]

[0002] Patent Document 1 discloses a plate fin stack type heat exchanger. This plate fin stack type heat exchanger is constructed by stacking a plurality of plate fins each having a header flow path and a heat transfer flow path. The plate fins are constructed by brazing a pair of plates facing each other, and a first fluid such as a refrigerant that flows from one header flow path into a heat transfer flow path flows to the other header flow path which serves as an outlet, and heat is exchanged between the first fluid flowing in the heat transfer flow path and a second fluid such as air flowing in the gaps between the plate fins. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2018-66532 A Summary of the Invention [Problem to be solved by the invention]

[0004] The present disclosure provides a lightweight, highly reliable, high-performance plate fin stacked heat exchanger that solves the problems arising from the above-described conventional plate fin configuration, and a refrigeration system using the same. [Means for solving the problem]

[0005] The plate fin stacked type heat exchanger of the present disclosure is a heat exchanger constructed by stacking a plurality of plate fins, each having a heat transfer flow path between header flow paths, and the plate fin comprises a header region having a header flow path and a flow path region having a heat transfer flow path, the header region being constructed by joining two plates having a header flow path opening, and the flow path region being constructed from a single flow path plate with the heat transfer flow path integrally molded, and the header region and flow path region being joined together to form the plate fin. Effect of the Invention

[0006] With the above-described configuration of the plate fin stacked heat exchanger disclosed herein, the flow path region is formed by integrally molding the heat transfer flow paths into the plates, so that the number of joining points is minimized to just the header region, improving reliability, and reducing weight compared to a configuration in which two plates are joined together. The thin configuration also reduces the flow resistance of the second fluid flowing between the plate fins, resulting in a highly reliable, lightweight, and high-performance plate fin stacked heat exchanger and a refrigeration system using it. [Brief description of the drawings]

[0007] [Figure 1] FIG. 1 is an exploded perspective view showing the appearance of a plate fin stack type heat exchanger according to a first embodiment. [Diagram 2] FIG. 2 is a perspective view showing a part of a plate fin stack of the plate fin stack type heat exchanger of the same embodiment; [Diagram 3] FIG. 2 is a perspective view showing the overall configuration of the plate fins of the plate fin stack type heat exchanger of the same embodiment; [Figure 4] FIG. 2 is a perspective view showing an expanded header region of the plate fins of the plate fin stacked heat exchanger of the same embodiment; [Diagram 5] FIG. 1 is an enlarged perspective view of a main portion of the plate fins of the plate fin stacked type heat exchanger of the present invention; [Figure 6] Cross section AA of Figure 2 [Figure 7] Enlarged cross-sectional view of the main part of Figure 6 [Figure 8] Cross section B-B of Figure 2 [Figure 9] 11A and 11B are perspective views showing plate fins in an unfolded state, a completed state, and a stacked state in another embodiment; [Figure 10] FIG. 1 is a diagram showing a refrigeration cycle of an air conditioner as an example of a refrigeration system using the plate fin stack type heat exchanger. [Figure 11] FIG. 3 is a cross-sectional view showing an indoor unit of the air conditioner. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] (The knowledge and other information that formed the basis of this disclosure) At the time when the inventors came up with the present disclosure, the plate fins of the plate fin stacked heat exchanger were configured by brazing two plates, each having an opening for a header passage and a groove for a heat transfer passage, facing each other, as shown in Patent Document 1, and the number of joining points and the complexity of the passage configuration made it easy for joining failures to occur. Therefore, there was a problem that it was necessary to reduce joining failures and improve reliability. In addition, since the plate fins were configured by joining two plates, the plate fins had a thick wall configuration, which increased the flow resistance of the fluid flowing between the plate fins, reducing the heat exchange performance, and also making the heat exchanger heavy overall.

[0009] The present inventors have discovered such a problem and have come to form the subject of the present disclosure in order to solve the problem.

[0010] Therefore, the present disclosure provides a highly reliable, lightweight, high-performance plate fin stacked heat exchanger and a refrigeration system using the same.

[0011] Hereinafter, the embodiments will be described in detail with reference to the drawings. However, more detailed explanation than necessary may be omitted. For example, detailed explanation of already well-known matters or duplicate explanation of substantially the same configuration may be omitted. This is to avoid the following explanation becoming more redundant than necessary and to facilitate understanding by those skilled in the art.

[0012] It should be noted that the accompanying drawings and the following description are provided to enable those skilled in the art to fully understand the present disclosure, and are not intended to limit the subject matter described in the claims.

[0013] (Embodiment 1) Hereinafter, the first embodiment will be described with reference to FIGS.

[0014] [1-1. Configuration] 1, the heat exchanger 1 of this embodiment is configured by integrally joining end plates 3a, 3b having approximately the same shape in a plan view to both sides of a plate fin stack 2 in which rectangular plate fins 2a are stacked. One end of the plate fin stack 2 has a tube A4 that serves as an inlet when used as a condenser and an outlet when used as an evaporator, and a tube B5 that serves the opposite purpose.

[0015] The end plates 3a, 3b on either side of the plate fin stack 2 are joined by brazing in a manner that sandwiches the plate fin stack 2, and both longitudinal ends are connected and fixed by fastening means 7, thereby maintaining the rigidity of the heat exchanger.

[0016] 2 and 3, the plate fins 2a have heat transfer paths 8 through which a first fluid such as a coolant (hereinafter referred to as coolant) flows, and are stacked in large numbers to form stacking gaps between the plate fins 2a through which a second fluid such as air (hereinafter referred to as air) flows. Heat is exchanged between the coolant flowing through the heat transfer paths 8 provided in the plate fins 2a and the air flowing through the stacking gaps between the plate fins 2a.

[0017] As shown in FIG. 4, the plate fin 2a includes left and right header regions 11, 11 having a header flow path A9 connected to tube A4 and a header flow path B10 connected to tube B5, and a flow path region 12 having a heat transfer flow path 8 connecting the header flow paths A9, B10, and is configured by connecting and joining these header regions 11, 11 and the flow path region 12 together.

[0018] 5, a first plate 16a having a header passage opening A9a (B10a), a ring-shaped groove 13 formed on its outer periphery, a communication passage groove 14 derived from the ring-shaped groove 13, and a passage cover portion 15 connected to the communication passage groove 14, and a second plate 16b having a header passage opening A9a (B10a) and the ring-shaped groove 13 formed on its outer periphery, are brazed together face to face. In this example, a connecting piece portion 17 is provided on one side of the first plate 16a and the second plate 16b, and the connecting piece portion 17 is bent to be joined face to face.

[0019] On the other hand, the flow path region 12 is formed by integrally molding the heat transfer flow path 8 into a single flow path plate 18, in this example by extrusion molding, and its ends are sandwiched between the first plate 16a and the second plate 16b of each of the left and right header region portions 11, 11 and brazed to be integrated with the header region portions 11, 11.

[0020] The connection and joining configuration between the header region 11, 11 on the left and right and the flow path region 12 is basically the same, so the connection and joining configuration between the header region 11 and the flow path region 12 provided with the header flow path opening A9a will be described in more detail with reference to Fig. 5. At the end of the flow path region 12, the end portion 12ab of the heat transfer flow path forming portion 12a is formed so as to protrude toward the header region 11 side beyond the fin portion 12b. The end portion 12ab of the heat transfer flow path forming portion 12a is sandwiched between the flow path cover portion 15 provided on the first plate 16a of the header region 11 and the flat surface portion of the second plate 16b, and is connected and joined by brazing. As a result, a series of passages connecting the header flow paths A9, B10 is formed between the flow path cover portion 15 of the first plate 16a and the end portion 12ab of the heat transfer flow path 8 of the flow path plate 18.

[0021] Here, a convex rib 22 is provided on the flat surface portion of the header region 11, 11, and as shown in Figure 7, when the plate fins 2a are stacked, this convex rib 22 abuts against the flow path covering portion 15 of the adjacent plate fin 2a back to back and presses it against the end portion 12ab of the heat transfer flow path forming portion 12a.

[0022] In addition, as shown in FIG. 5, the heat transfer flow path 8 of the flow path region 12 is extrusion molded in two rows in this example, and a convex portion 12c is provided on the back side of the fin portion 12b between the heat transfer flow path forming portions 12a, as shown in FIG. 5, to cause the air flowing between the plate fin stacking spaces to meander.

[0023] Furthermore, the plurality of heat transfer flow paths 8 arranged in parallel are connected by auxiliary communication flow path portions 19 recessed in the header regions 11, 11, and are configured to turn between the header flow paths A9, B10.

[0024] The end plates 3a, 3b and the plate fins 2a are made of aluminum or an aluminum alloy.

[0025] [1-2. Operation] Next, the operation and effect of the plate fin laminated type heat exchanger constructed as above will be described by taking as an example the case where it is used as a heat exchanger for an air conditioner.

[0026] When the heat exchanger 1 of this embodiment is used under condensing conditions, for example, the gas-phase refrigerant flows from tube A4 into the header flow passage A9 on the inlet side of the plate fin stack 2. The gas-phase refrigerant that flows into the header flow passage A9 turns around and flows through the heat transfer flow passages 8 of each plate fin 2a, and flows out of tube B5 into the refrigerant circuit of the refrigeration system via the header flow passage B10 on the outlet side. Then, while flowing through the heat transfer flow passage 8, the refrigerant exchanges heat with air passing through the gaps between the plate fins of the plate fin stack 2, and the gas-phase refrigerant gradually becomes liquid and flows out of the header flow passage B10.

[0027] Here, the header regions 11, 11 of the plate fins 2a through which the refrigerant flows are formed by brazing together the first and second plates 16a, 16b, while the flow path region 12 having the heat transfer flow paths 8 is formed by a single flow path plate 18 formed by extruding the heat transfer flow paths 8. Therefore, in this heat exchanger 1, the number of joints made by brazing can be minimized to only the header region 11, and reliability can be significantly improved.

[0028] On the other hand, since the flow path region 12 of the plate fin 2a is formed from a single flow path plate 18 formed by extruding the heat transfer flow paths 8, the plate thickness of the fin portion 12b of the flow path region 12 is thinner than the total plate thickness of the brazed first and second plates 16a, 16b of the header region 11. As shown in Fig. 7, the thickness width t of the heat transfer flow path forming portion 12a of the flow path region 12 is also thinner than the thickness width T of the communication passage groove 14 of the header region 11 formed by joining the first and second plates 16a, 16b, that is, the thickness width T corresponding to the portion having the heat transfer flow path formed by joining two conventional plates.

[0029] 8, the lamination interval L of the flow path region 12 which serves as the air passage can be increased accordingly, reducing the air flow resistance and improving performance. In addition, the convex rib portion 12c protrudes from the lamination interval L of the flow path region 12, causing the air to meander as indicated by the dashed arrow Y, thereby further improving performance.

[0030] Furthermore, the plate fins 2a are lighter in weight due to the thinner flow passage region 12. Therefore, the weight of the entire heat exchanger 1 can be significantly reduced, making it possible to reduce the weight.

[0031] As shown in FIG. 5, the header regions 11, 11 and flow path region 12 of the plate fin 2a are joined by sandwiching the end portion 12ab of the heat transfer flow path forming portion 12a protruding from the fin portion 12b of the flow path region 12 between the flow path covering portion 15 provided on the first plate 16a of the header regions 11, 11 and the flat surface portion of the second plate 16b. This makes it possible to easily join the header regions 11, 11 and to ensure a reliable brazing joint by suppressing poor joining.

[0032] In this embodiment, convex ribs 22 are provided on the flat surface portion of the second plate 16b so as to press down the flow path covering portions 15 of adjacent plate fins 2a when the plate fins 2a are stacked. This makes it possible to firmly maintain the plate bond against the plate peeling pressure from the refrigerant applied to the joint between the flow path covering portion 15 and the end portion 12ab of the heat transfer flow path forming portion 12a, thereby making it possible to improve the airtightness of the flow path joint formed by the flow path covering portion 15 through which the first fluid flows and the end portion 12ab of the heat transfer flow path forming portion 12a, and thereby further improving reliability.

[0033] Furthermore, since the first plate 16a and the second plate 16b constituting the header area 11, 11 are connected by a connecting piece portion 17, the first plate 16a and the second plate 16b can be managed as a single part, thereby reducing the number of parts and also making parts management easier.

[0034] In the present embodiment, the header regions 11, 11 having the header flow paths A9, B10 are provided separately on both ends of the plate fin 2a, but as shown in FIG. 9, the header region 11 in which the header flow paths A9, B10 are provided collectively and the auxiliary flow path region 21 in which only the communication paths 20 connecting the heat transfer flow paths 8 are provided may be integrally joined to the left and right ends of the flow path region 12, and the header flow paths A9, B10 may be provided collectively on one end side of the plate fin 2a.

[0035] In this way, the same effect as above can be obtained by providing the header flow paths A9, B10 together on one end side of the plate fins 2a. In addition, with the above-mentioned configuration, the header flow paths A9, B10 are together on one end side of the plate fins 2a of the heat exchanger 1, so that the piping connection work from the refrigeration system to each of the header flow paths A9, B10 can be performed at one location.

[0036] [1-3. Effects, etc.] As described above, the plate fin stacked type heat exchanger of the present disclosure is a heat exchanger constructed by stacking a plurality of plate fins 2a, each having a heat transfer flow path 8 between header flow paths A9, B10, and the plate fin 2a comprises a header region 11 having a header flow path and a flow path region 12 having the heat transfer flow path 8. The header region 11 is constructed by joining two plates 16a, 16b, each having a header flow path opening, and the flow path region 12 is constructed from a single flow path plate 18 into which the heat transfer flow path 8 is integrally molded. The header region 11 and the flow path region 12 are integrally joined to form the plate fin 2a.

[0037] As a result, the flow path region 12 is a single flow path plate 18 with the heat transfer flow path 8 integrally formed therewith, and therefore the only joining point is the header region 11, minimizing the number of joining points such as brazing. This improves reliability, and also reduces the weight and thickness compared to a configuration in which two plates 16a, 16b are joined together, thereby reducing the flow resistance of the second fluid, resulting in a lightweight, high-performance, and highly reliable plate fin stacked type heat exchanger.

[0038] The plate fin stacked type heat exchanger of the present disclosure is a heat exchanger configured by stacking a plurality of plate fins 2a, each having a heat transfer flow path 8 between header flow paths A9, B10, and the plate fin 2a includes a header region 11 that collectively arranges a pair of header flow paths A9, B10, a flow path region 12 that has a heat transfer flow path 8 connecting the pair of header flow paths A9, B10, and an auxiliary flow path region 21 that has communication passages 20 connecting the heat transfer flow paths, and the header region 11 is joined and integrated to one end side of the flow path region 12, and the auxiliary flow path region 21 is joined and integrated to the other end side of the flow path region 12 to form the plate fin 2a.

[0039] As a result, the header flow paths A9, B10 are gathered together on one end side of the plate fins of the heat exchanger 1, which, as described above, reduces the weight of the heat exchanger and improves its reliability and performance, while also improving the ease of connecting piping from the refrigeration system to each header flow path A9, B10.

[0040] Furthermore, in the plate fin stacked type heat exchanger of the present disclosure, both end portions 12ab of the heat transfer flow path forming portion 12a provided in the flow path region 12 are protruded, and both end portions 12ab of the heat transfer flow path forming portion 12a are sandwiched between two plates 16a, 16b of the header region 11, 11 or the header region 11, 11 and the auxiliary flow path region 21 and joined together.

[0041] This allows the header regions 11, 11 and the flow path region 12 to be easily brazed and joined, and the brazing can be made robust and reliable.

[0042] (Embodiment 2) The second embodiment will be described below with reference to FIGS.

[0043] [2-1. Configuration] FIG. 10 is a diagram of a refrigeration cycle of an air conditioner configured using the plate fin stack type heat exchanger in accordance with the first embodiment, and FIG. 11 is a schematic cross-sectional view showing an indoor unit of the same air conditioner.

[0044] 10 and 11, this air conditioner is composed of an outdoor unit 51 and an indoor unit 52 connected to the outdoor unit 51. The outdoor unit 51 is provided with a compressor 53 for compressing the refrigerant, a four-way valve 54 for switching the refrigerant circuit during cooling and heating operation, an outdoor heat exchanger 55 for exchanging heat between the refrigerant and the outside air, a pressure reducer 56 for reducing the pressure of the refrigerant, and an outdoor blower 59. The indoor unit 52 is provided with an indoor heat exchanger 57 for exchanging heat between the refrigerant and the indoor air, and an indoor blower 58. The plate-fin laminated type heat exchanger exemplified in the first embodiment is used for the indoor heat exchanger 57, and the compressor 53, the four-way valve 54, the indoor heat exchanger 57, the pressure reducer 56, and the outdoor heat exchanger 55 are connected by a refrigerant circuit to form a heat pump type refrigeration cycle.

[0045] [2-2. Operation] In the air conditioner having the above configuration, during cooling operation, the four-way valve 54 is switched so that the discharge side of the compressor 53 communicates with the outdoor heat exchanger 55. As a result, the refrigerant compressed by the compressor 53 becomes a high-temperature, high-pressure gas-phase refrigerant and is sent to the outdoor heat exchanger 55 through the four-way valve 54. Then, the refrigerant exchanges heat with the outdoor air, dissipates heat, becomes a high-pressure liquid-phase refrigerant, and is sent to the pressure reducer 56. The pressure is reduced in the pressure reducer 56 to become a low-temperature, low-pressure two-phase refrigerant, and is sent to the indoor unit 52. In the indoor unit 52, the refrigerant enters the indoor heat exchanger 57, exchanges heat with the indoor air, absorbs heat, and evaporates to become a low-temperature gas refrigerant. At this time, the indoor air is cooled to cool the room. The refrigerant then returns to the outdoor unit 51 and is returned to the compressor 53 via the four-way valve 54.

[0046] During heating operation, the four-way valve 54 is switched so that the discharge side of the compressor 53 communicates with the indoor unit 52. As a result, the refrigerant compressed by the compressor 53 becomes a high-temperature, high-pressure refrigerant and passes through the four-way valve 54 to be sent to the indoor unit 52. The high-temperature, high-pressure refrigerant enters the indoor heat exchanger 57, exchanges heat with the indoor air, releases heat, and is cooled to become a high-pressure liquid refrigerant. At this time, the indoor air is heated to heat the room. The refrigerant is then sent to the pressure reducer 56, where it is reduced in pressure to become a low-temperature, low-pressure two-phase refrigerant, which is then sent to the outdoor heat exchanger 55, where it exchanges heat with the outdoor air and evaporates, and is returned to the compressor 53 via the four-way valve 54.

[0047] [2-3. Effects, etc.] The refrigeration system of the present disclosure uses the heat exchanger shown in the first embodiment for indoor heat exchanger 57, and therefore can be a lightweight, high-performance, and highly reliable refrigeration system.

[0048] [Other embodiments] The plate-fin stacked heat exchanger and the refrigeration system using the same according to the present invention have been described above using the above-mentioned embodiment, but the present invention is not limited thereto, and various modifications, substitutions, additions, omissions, etc. can be made. For example, the first fluid is a refrigerant and the second fluid is air, but the present invention is not limited thereto. In addition, an air conditioner is exemplified as the refrigeration system, but it may be a refrigerator or a freezer case, or it may be a heat pump water heater in which the second fluid is water. In other words, the embodiment disclosed here is illustrative in all respects and not restrictive, and the scope of the present invention is indicated by the claims, and includes all modifications within the meaning and scope equivalent to the claims. [Industrial Applicability]

[0049] As described above, the present invention can provide a lightweight, highly reliable, high-performance plate-fin stacked heat exchanger and a refrigeration system using the same, which can be widely used in heat exchangers for home and commercial air conditioners and various refrigeration appliances, and has great industrial value. [Explanation of symbols]

[0050] 1 heat exchanger 2 Plate Fin Stack 2a Plate fin 3a, 3b End plates 4 Pipe A 5 Tube B 7 Fastening means (bolts and nuts) 8 Heat transfer path 9 Header passage A 10 Header passage B 11 Header area 12 Flow passage area 12a Heat transfer channel forming part 12ab end part 12b Fin section 12c Convex part 13 Ring-shaped groove 14. Groove for connecting passage 15 Flow passage cover 16a 1st Plate 16b 2nd Plate 17 Connecting piece 18 Flow path plate 19 Auxiliary connecting flow passage 20 Connecting Passage 21 Auxiliary flow area 22 Convex rib 51 Outdoor unit 52 Indoor unit 53 Compressor 54 Four-way valve 55 Outdoor heat exchanger 56 Pressure reducer 57 Indoor heat exchanger 58 Indoor fan 59 Outdoor blower

Claims

1. A plate-fin stacked heat exchanger comprising a plurality of plate fins, each having a heat transfer flow path between header flow paths, the plate fin comprising a header region having a header flow path, and a flow path region having a heat transfer flow path connecting the header flow paths, the header region being formed by joining two plates having a header flow path opening, and the flow path region being formed by a single plate having a heat transfer flow path integrally molded therein, the header region and the flow path region being joined together to form a plate fin, the plate fin having two header flow path openings, and a flow path connecting one of the header flow path openings to the other header flow path opening, wherein the plate fin has a single flow path.

2. A plate-fin stacked heat exchanger comprising a plurality of stacked plate fins, each having a heat transfer flow path between header flow paths, wherein the plate fin comprises a header region in which a pair of header flow paths are arranged together, a flow path region having a heat transfer flow path connecting the pair of header flow paths, and an auxiliary flow path region having a communication passage connecting the heat transfer flow paths, the header region is joined and integrated to one end side of the flow path region, and the auxiliary flow path region is joined and integrated to the other end side of the flow path region to form a plate fin, and a flow path connecting one of the pair of header flow paths to the other header flow path is single within the plate fin.

3. 3. A plate-fin stacked type heat exchanger as claimed in claim 1 or 2, wherein the flow passage region has end portions of the heat transfer flow passage forming portions protruding from both ends, and the end portions are sandwiched and integrated between two plates of the header region or the header region and the auxiliary flow passage region.

4. A refrigeration system in which a heat exchanger is the plate fin stacked type heat exchanger according to any one of claims 1 to 3.

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