Heat exchanger

Abstract

To provide a heat exchanger excellent in corrosion resistance of an external package.SOLUTION: An external package 1 provided with an inlet and an outlet allows a heat exchange medium flowing from the inlet to pass through the external package 1 and flow out from the outlet. The external package 1 is composed of an external packaging laminate material L1 in which a resin heat fusion layer 52 is provided on at least an inner face side of a metal heat transfer layer 51. The heat transfer layer 51 of the external package 1 is composed of titanium.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] This invention relates to a heat exchanger manufactured using a laminate material in which a resin heat-sealing layer is laminated on a metal heat transfer layer.

[0002] In the present invention, the term "titanium (Ti)" is used to also include "titanium alloy (Ti alloy)".

Background Art

[0003] With the miniaturization and high performance of electronic devices such as smartphones and personal computers, heat countermeasures around the CPU of electronic devices have become important. Depending on the model, a water-cooled cooler or a heat pipe is incorporated to reduce the heat load on electronic components such as the CPU and prevent heat from accumulating inside the housing, thereby avoiding adverse effects caused by heat. Technologies have been proposed conventionally.

[0004] In addition, battery modules mounted on electric vehicles and hybrid vehicles generate a large amount of heat due to repeated charging and discharging. For this reason, in battery modules as well, technologies have been proposed to incorporate a water-cooled cooler or a heat pipe to avoid adverse effects caused by heat, similar to the above-mentioned electronic devices.

[0005] Furthermore, for power modules made of silicon carbide (SiC) etc., countermeasures such as attaching a cooling plate or a heat sink have been proposed as heat countermeasures.

[0006] Conventionally, thin coolers such as heat pipes incorporated in small electronic devices have mainly been made of metal, in which a plurality of metal components are joined by brazing etc. (Patent Documents 1 to 3).

[0007] Such metal coolers are difficult to make thinner than the current level because each component is manufactured by troublesome metal processing (machining) such as plastic processing like casting and forging, and removal processing like cutting.

[0008] Therefore, a cooler has been proposed in which an outer casing and inner fins (core materials) as casings are made of a laminate material. The laminate material is composed of a metal foil layer laminated with a resin heat-sealing layer, and the heat-sealing layer of the laminate material for the outer casing is heat-sealed (heat-fused) to the heat-sealing layer of the laminate material for the inner fins to form a cooler.

[0009] In recent years, coolers made of laminate materials have attracted attention because they do not require troublesome metal processing, and can facilitate production, reduce costs, and achieve thinning.

Prior Art Documents

Patent Documents

[0010]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0011] Under such a technical background, in a heat exchanger using a laminate material, when the metal foil layer in the outer casing and inner fins is reliably covered by the resin layer, it has sufficient corrosion resistance. However, due to the pressure during heat fusion, etc., the heat-sealing layer (resin layer) may partially flow out with respect to the metal foil layer, and the metal foil layer may be exposed. If so, there is a risk that moisture such as cooling water contacts the exposed metal foil layer and causes corrosion deterioration. In addition, the outer casing and inner fins are manufactured by cutting the laminate material, and at the cut edge, the metal foil layer may be exposed, and there is also a risk that the exposed metal foil layer contacts moisture such as cooling water and causes corrosion deterioration as described above.

[0012] When the metal foil layer corrodes and deteriorates in this way, problems such as liquid leakage and bulging deformation occur in the corroded and deteriorated parts, leading to a decrease in reliability.

[0013] This invention has been made in view of the above problems, and in a heat exchanger using a laminate material, it is possible to prevent corrosion and deterioration of the heat transfer layer, prevent liquid leakage and bulging deformation, and obtain a heat exchanger with high reliability.

Means for Solving the Problems

[0014] In order to solve the above problems, the present invention comprises the following means.

[0015] [1] A heat exchanger comprising an outer casing provided with an inlet and an outlet, wherein the heat exchange medium flowing in from the inlet passes through the inside of the outer casing and flows out from the outlet, The outer casing is composed of an outer casing laminate material provided with a heat-fused resin layer on at least the inner surface side of a metal heat transfer layer, The heat transfer layer of the outer casing is characterized in that it is made of titanium.

[0016] [2] The heat exchanger according to item 1 above, wherein the titanium constituting the heat transfer layer of the outer casing is grade 1 of ASTM B265.

[0017] [3] An inner fin having uneven portions is disposed inside the outer casing, The inner fin is composed of an inner core laminate material provided with heat-fused resin layers on both sides of a metal heat transfer layer, The heat exchanger according to item 1 or 2 above, wherein the heat transfer layer of the inner fin is made of titanium.

[0018] [4] A heat exchanger comprising an outer casing provided with an inlet and an outlet, and an inner fin disposed inside the outer casing and having uneven portions, wherein the heat exchange medium flowing in from the inlet passes through the inside of the outer casing and flows out from the outlet, The outer package is composed of an outer package laminate material in which a heat-fusing layer made of resin is provided at least on the inner surface side of a heat-conducting layer made of metal. The inner fin is composed of a core laminate material in which heat-fusing layers are provided on both sides of a heat-conducting layer made of metal. The heat exchanger is characterized in that the heat-conducting layer of the inner fin is made of titanium. [5] The heat exchanger according to item 3 or 4 above, wherein the titanium constituting the heat-conducting layer of the inner fin is grade 1 of ASTM B265.

[0019] [6] The outer package has a pair of opposing walls, and the inner fin is disposed between the pair of opposing walls. The heat exchanger according to any one of items 3 to 5 above, wherein the inner fin is formed in a square wave shape in which the bottom wall of the recess and the top wall of the protrusion are arranged parallel to the pair of opposing walls, and the rising wall connecting between the bottom wall of the recess and the top wall of the protrusion is orthogonal to the pair of opposing walls. [Advantages of the Invention]

[0020] According to the heat exchanger of Invention [1], since the heat-conducting layer of the outer package is made of titanium with excellent corrosion resistance, even if the heat-conducting layer of the outer package is exposed and comes into contact with moisture, the corrosion deterioration of the heat-conducting layer can be effectively prevented, and liquid leakage and bulging deformation due to the corrosion deterioration can be prevented, and high reliability can be obtained.

[0021] According to the heat exchanger of Invention [2], since a specific titanium with even more excellent corrosion resistance is used as the heat-conducting layer of the outer package, corrosion deterioration can be more surely prevented.

[0022] According to the heat exchangers of Invention [3][4], since the heat-conducting layer of the inner fin is made of titanium with excellent corrosion resistance, even if the heat-conducting layer of the inner fin is exposed and comes into contact with moisture, the corrosion deterioration of the heat-conducting layer can be effectively prevented, and liquid leakage and bulging deformation due to the corrosion deterioration can be prevented, and high reliability can be obtained.

[0023] According to the heat exchanger of the invention [5], since a specific titanium with even better corrosion resistance is used as the heat transfer layer of the inner fin, corrosion deterioration can be more reliably prevented.

[0024] According to the heat exchanger of the invention [6], since the inner fin is formed in a square wave shape, the bottom wall of the concave portion and the top wall of the convex portion of the inner fin become flat, and the contact area with the outer package can be increased. Therefore, the heat transfer performance between the inner fin and the outer package can be improved, and the heat exchange performance can be improved.

Brief Description of the Drawings

[0025]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Mode for Carrying Out the Invention

[0026] Figs. 1 to 3 are diagrams showing a heat exchanger according to an embodiment of the present invention. In the following description, for the sake of easy understanding of the invention, the left - right direction in Fig. 2(a) will be described as the "front - rear direction", and further, the up - down direction in Fig. 2(b) will be described as the "up - down direction (thickness direction)".

[0027] As shown in Figs. 1 to 3, the heat exchanger of the present embodiment is used as a heat transfer panel, a heat transfer tube, etc., and includes an outer package 1 as a casing (container), an inner fin (inner core material) 2 housed inside the outer package 1, and a pair (both sides) of headers (joint members) 3, 3 housed at both ends of the outer package 1.

[0028] The outer package 1 is composed of a tray member 10 having a rectangular shape in plan view and a cover member 15 having a rectangular shape in plan view.

[0029] The tray member 10 is formed of a molded product of an outer - package laminate material L1. By using a cold - forming method such as deep - drawing molding or extrusion molding, the entire intermediate region except the outer peripheral edge portion is recessed downward, and a recessed portion 11 having a rectangular shape in plan view is formed. At the same time, a flange portion 12 protruding outward is integrally formed on the outer periphery of the opening edge portion of the recessed portion 11.

[0030] In addition, a pair of inlets / outlets 16, 16 are formed in the cover member 15 corresponding to the front and rear end portions of the recessed portion 11 in the tray member 10. Needless to say, in the present embodiment, of the pair of inlets / outlets 16, one inlet / outlet 16 is configured as an inlet, and the other inlet / outlet 16 is configured as an outlet.

[0031] The tray member 10 and the cover member 15 are composed of an outer - package laminate material L1 which is a laminate sheet or film having flexibility and flexibility.

[0032] As shown in FIG. 4, the outer packaging laminate material L1 includes a heat transfer layer 51 made of metal (metal foil), a heat-sealable resin film or a heat-sealable resin sheet heat-sealable layer 52 laminated via an adhesive on one surface (inner surface) of the heat transfer layer 51, and a protective layer 53 made of a heat-resistant resin film or a heat-resistant resin sheet laminated via an adhesive on the other surface (outer surface) of the heat transfer layer 51. In this embodiment, the term "foil" is used to include films, thin plates, and sheets.

[0033] As the metal constituting the heat transfer layer 51 in the outer packaging laminate material L1, titanium (including its alloys) is used. Among them, in particular, it is preferable to use an annealed foil of pure titanium of grade 1 of ASTM B265, that is, an annealed foil of pure titanium with N: 0.03% by mass or less, C: 0.08% by mass or less, Fe: 0.20% by mass or less, H: 0.015% by mass or less, and O: 0.018% by mass or less.

[0034] In this embodiment, by using the above titanium foil as the heat transfer layer 51 of the outer packaging laminate material L1, the corrosion resistance of the heat transfer layer 51 can be improved, and the corrosion resistance of the outer packaging laminate material L1, that is, the outer package 1, can be improved.

[0035] The heat transfer layer 51, which is also referred to as a heat collection layer, is preferably one with a thickness of 30 μm to 200 μm, and more preferably 40 μm to 180 μm. That is, when the thickness of the heat transfer layer 51 is too thin, it is likely to deform under external pressure and the strength may decrease, which is not preferable. Conversely, when the thickness of the heat transfer layer 51 is too thick, the flexibility may decrease and the formability may decrease, which is not preferable.

[0036] Also, the heat transfer layer 51 can be further improved in durability, such as preventing corrosion of the heat transfer layer 51 and improving the adhesiveness with the resin, by performing surface treatment such as chemical conversion treatment.

[0037] As the heat-sealing layer 52, a film or sheet made of a polyolefin resin such as polyethylene or polypropylene, a modified resin thereof, a fluororesin, a polyester resin, a vinyl chloride resin, etc. can be preferably used.

[0038] As the heat-sealing layer 52, it is preferable to use one with a thickness of 20 μm to 500 μm.

[0039] In particular, as the heat-sealing layer 52, an unstretched polypropylene (CPP) with a thickness of 20 μm to 500 μm, more preferably 30 μm to 80 μm, composed of a three-layer (random PP / block PP / random PP) coextruded film can be preferably used.

[0040] Also, as the protective layer 53, a film or sheet of a stretched polyester resin (PET, PBT, etc.), a stretched polyamide resin (ONY), etc. with a melting point 10°C or more, more preferably 20°C or more higher than that of the heat-sealing layer 52 can be preferably used.

[0041] Furthermore, as the protective layer 53, it is good to use one with a thickness of 6 μm to 100 μm.

[0042] Also, as the adhesive for adhering between the heat transfer layer 51, the heat-sealing layer 52, and the protective layer 53 that constitute the outer packaging laminate material L1, a urethane-based adhesive, an epoxy-based adhesive, an olefin-based adhesive, etc. with a thickness of 1 μm to 5 μm can be preferably used.

[0043] In this embodiment, a three-layer structure sheet is used as the laminate material L1 that constitutes the outer package 1, but it is not limited thereto. In the present invention, a two-layer structure sheet of a heat transfer layer and a heat-sealing layer may be used, or a sheet with a structure of four or more layers may be used. When using a sheet with a structure of four or more layers, for example, another layer may be interposed between the protective layer and the heat transfer layer, or another layer may be interposed between the heat transfer layer and the heat-sealing layer to form a structure of four or more layers.

[0044] The tray member 10 and the cover member 15 of the outer package 1 are formed by the outer package laminate material L1 having the above configuration. Then, as will be described in detail later, the cover member 15 is attached to the tray member 10 so as to close the opening of the recessed portion 11, whereby the outer package 1 is formed.

[0045] In this embodiment, a pair of opposing walls 111, 151 are formed by the bottom wall (lower wall) 111 of the recessed portion 11 in the tray member 10 and the top wall (upper wall) 151 of the portion corresponding to the recessed portion 11 in the cover member 15 attached to the tray member 10.

[0046] As shown in FIGS. 1 to 4, the inner fin 2 accommodated in the hollow portion (recessed portion) 11 of the outer package 1 is composed of an inner core laminate material L2 which is a laminate sheet or film having flexibility or flexibility.

[0047] As shown in FIG. 4, the inner core laminate material L2 includes a heat transfer layer 61 made of a metal foil and heat fusion layers 62, 62 made of a resin film or resin sheet laminated on both sides of the heat transfer layer 61 via an adhesive.

[0048] As the metal constituting the heat transfer layer 61 in the inner core laminate material L2, titanium (including its alloys) is used. Among them, in particular, it is preferable to use an annealed foil of pure titanium of grade 1 of ASTM B265, that is, an annealed foil of pure titanium with N: 0.03% by mass or less, C: 0.08% by mass or less, Fe: 0.20% by mass or less, H: 0.015% by mass or less, and O: 0.018% by mass or less.

[0049] In this embodiment, by using the above titanium foil as the heat transfer layer 61 of the inner core laminate material L2, the corrosion resistance of the heat transfer layer 61 can be improved, and the corrosion resistance of the inner core laminate material L2, that is, the inner fin 2 can be improved.

[0050] As the heat transfer layer 61, it is preferable to use one with a thickness of 30 μm to 200 μm, and more preferably one with a thickness of 40 μm to 180 μm. That is, when the thickness of the heat transfer layer 61 is too thin, it is likely to deform under external pressure and the strength may decrease, which is not preferable. Conversely, when the thickness of the heat transfer layer 61 is too thick, the flexibility may decrease and the formability may decrease, which is not preferable.

[0051] As the heat fusion layer 62, a film or sheet composed of polyolefin resins such as polyethylene and polypropylene, or modified resins thereof, fluorine-based resins, polyester-based resins, vinyl chloride resins, etc. can be preferably used. Among them, in particular, it is preferable to use a film or sheet composed of unstretched polypropylene (CPP).

[0052] As the heat fusion layer 62, it is preferable to use one with a thickness of 20 μm to 5000 μm, and more preferably one with a thickness of 30 μm to 80 μm.

[0053] In this embodiment, a three-layer structure sheet is used as the laminate material L2 constituting the inner fin 2, but it is not limited thereto. In the present invention, a sheet with a structure of four or more layers may be used. For example, by interposing another layer between the heat fusion layer and the heat transfer layer, a sheet with a structure of four or more layers may be adopted.

[0054] Also, the processing method of the inner fin 2 is not particularly limited. For example, a method of forming unevenness by sandwiching the inner core laminate material L2 between a pair of embossing rolls or a pair of corrugated rolls and passing it between the pair of rolls can be exemplified. Furthermore, a method of forming uneven portions on the inner core laminate material L2 using a press machine or a press die can be exemplified.

[0055] As shown in FIGS. 2 to 5, the inner fin 2 is formed in a square wave shape (rectangular wave shape), i.e., a so-called digital signal waveform, in which the concave portions 25 and the convex portions 26 are alternately and continuously formed. That is, the bottom surface (bottom wall) of the concave portion and the top surface (top wall) of the convex portion of the inner fin 2 in the present embodiment are formed flat, and in the state where the heat exchanger is assembled, they are arranged parallel to the bottom wall (lower wall) 111 of the tray member 10 and the top wall (upper wall) 151 of the cover member 15. Further, the inner fin 2 has a rising wall connecting between adjacent bottom walls of the concave portions and top walls of the convex portions, which is arranged perpendicular to the bottom walls of the concave portions and the top walls of the convex portions, or perpendicular to the upper and lower walls 111 and 151 of the outer package 1 in the state where the heat exchanger is assembled.

[0056] In the present embodiment, the square wave-shaped inner fin 2 is used, but it is not limited thereto. In the present invention, a general wave shape (sine wave shape), i.e., a so-called analog signal waveform, in which concave portions and convex portions having a circular arc-shaped cross section are alternately and continuously formed, may be used. However, in the present invention, any shape of inner fin can be used as long as it is provided with concave portions and convex portions joined to the inner peripheral surface of the outer package.

[0057] This inner fin 2 is housed in the recess 11 of the tray member 10. In this case, the inner fin 2 is housed in the middle portion of the recess 11 of the tray member 10 excluding both front and rear end portions. Further, the inner fin 2 is arranged such that its ridge direction and valley direction coincide with the front-rear direction (left-right direction in FIG. 1) of the tray member 10. Thereby, the tunnel portions and groove portions formed by the ridge portions and valley portions of the inner fin 2 are configured as heat exchange channels. These heat exchange channels are arranged along the front-rear direction (length direction) of the tray member 10 and a plurality of them are arranged in parallel in the width direction (left-right direction), and the heat exchange medium (heat medium) can smoothly flow from one end side to the other end side in the front-rear direction of the outer package 1 while being evenly dispersed through each heat exchange channel.

[0058] As shown in FIGS. 2 and 3, a pair of headers 3, 3 arranged at both ends of the outer package 1 are composed of molded products of synthetic resin.

[0059] As the resin constituting the header 3, it is preferable to use the same type of resin as the resin constituting the heat-fused layers 52, 62 of the outer package 1 and the inner fins 2. Specifically, polyolefin resins such as polyethylene and polypropylene, or modified resins thereof, fluorine-based resins, polyester-based resins, vinyl chloride resins, etc. can be preferably used.

[0060] The header 3 includes a box-shaped mounting box portion 31 having an opening 32 on one side surface, and a pipe portion 33 provided on the upper wall of the mounting box portion 31. The pipe portion 33 communicates with the inside of the mounting box portion 31, and is configured such that a heat exchange medium can flow back and forth between the inside of the pipe portion 33 and the inside of the mounting box portion 31.

[0061] The molding method of the header 3 is not particularly limited, but for example, a method of molding using injection molding can be preferably employed.

[0062] The mounting box portion 31 of this header 3 is arranged on both sides of the inner fins 2 in the recessed portion 11 of the tray member 10. Further, the pipe portions 33 of the header 3 are arranged upward, and the opening 32 of the mounting box portion 31 is arranged inward, that is, facing the inner fins 2.

[0063] In this way, the headers 3, 3 are accommodated in the tray member 10, and the cover member 15 is arranged on the tray member 10 so as to close its opening. In this case, the upward pipe portions 33, 33 of the headers 3, 3 are inserted and arranged in the entrance / exit 16 of the cover member 15.

[0064] By heating the thus temporarily assembled heat exchanger temporary assembly, the members in contact with each other are heat-fused and joined integrally.

[0065] In this heat fusion, first, the overlapping portion between the flange portion 12 of the tray member 10 in the outer package 1 and the outer peripheral edge portion of the cover member 15 is heated while being sandwiched between a pair of upper and lower heat sealing dies (outer package fusion step). Thereby, the heat fusion layers 52 between the flange portion 12 of the tray member 10 and the outer peripheral edge portion of the cover member 15 are heat-fused (thermally adhered) to seal the hollow portion of the outer package 1 in an airtight or liquidtight state.

[0066] Subsequently, the intermediate region (lower wall 111 and upper wall 151) of the outer package 1 with the outer peripheral edge portion heat-fused is heated while being sandwiched between a pair of upper and lower heating plates. Thereby, the heat fusion layer 62 at the peak and bottom portions of the inner fin 2 and the heat fusion layer 52 of the bottom wall 111 of the tray member 10 and the intermediate region (upper wall) 151 of the cover member 15 are joined and integrated by thermal adhesion (heat fusion) to seal in a liquidtight or airtight state (fin fusion step). Further, in this fin fusion step, the outer peripheral surfaces of the mounting box portions 31, 31 of the headers 3, 3 and the heat fusion layer 52 of the corresponding tray member 10 and cover member 15 are joined and integrated by thermal fusion (thermal adhesion) to seal in a liquidtight or airtight state.

[0067] The heat exchanger thus assembled is arranged such that the pipe portions 33, 33 of the headers 3, 3 project upward from the upper walls (cover members 15) at both ends in the outer package 1.

[0068] Here, when the heat fusion portions between the inner fin 2 and the headers 3, 3 and the outer package 1 are made of the same kind of resin, the two can be firmly fixed with sufficient mounting strength.

[0069] In this embodiment, by performing the heat fusion treatment (heating treatment) under reduced pressure, the thermal adhesion can be strongly performed in a state where the adhesion between the tray member 10 and the cover member 15 and between the tray member 10 and the cover member 15 and the inner fin 2 and the headers 3, 3 in contact therewith is high, and the adhesion area can be widened. Therefore, it is preferable to perform the heat fusion treatment under reduced pressure.

[0070] In this embodiment, the heating temperature (welding temperature) during the heat fusion process is preferably set to 160°C to 250°C, more preferably 170°C to 210°C. Further, the pressure (welding pressure) during heat fusion is preferably set to 0.1 MPa to 0.5 MPa, more preferably 0.15 MPa to 0.4 MPa. Further, the fusion time (welding time) is preferably set to 2 seconds to 10 seconds, more preferably 3 seconds to 7 seconds.

[0071] Also, in this embodiment, the outer package fusion process of heat-fusing the flange portion 12 of the tray member 10 and the outer peripheral edge portion of the cover member 15, and the fin fusion process of heat-fusing the inner fins 2 and the headers 3, 3 and the outer package 1 are performed in separate heat treatments. However, the present invention is not limited thereto, and in the present invention, the outer package fusion process and the fin fusion process may be performed in the same heat treatment (one-stage heat fusion process).

[0072] Also, in this embodiment, particularly in the fin fusion process of the fusion process, a heat conductive rubber layer is disposed on the contact surface with the outer package 1 of a pair of heating plates that sandwich the lower wall 111 and the upper wall 151 of the outer package 1, so that the lower wall 111 and the upper wall 151 of the outer package 1 and the concave bottom surface and the convex top surface of the inner fin 2 can be surely brought into contact with each other, and the heat fusion process can be performed with high precision.

[0073] The heat exchanger configured as described above is used as a cooler (cooling device) for cooling a battery or the like as a member to be cooled (heat exchange target member). That is, an inflow pipe for allowing a coolant (cooling water, antifreeze, etc.) as a heat exchange medium (refrigerant) to flow into one pipe portion 33 of the heat exchanger is connected, and an outflow pipe for allowing the coolant to flow out is connected to the other pipe portion 33. Further, the battery as the member to be cooled is disposed in contact with the lower wall 111 and / or the upper wall 151 of the outer casing 1 of the heat exchanger. In that state, the coolant flows into the interior of the outer casing 1 from one pipe portion 33 through one header 3, the coolant is circulated through the portion of the inner fin 2, and flows out from the other pipe portion 33 through the other header 3. By circulating the coolant in the outer casing 1 in this way, heat exchange occurs between the coolant and the battery through the inner fin 2 and the upper and lower walls of the outer casing 1, and the battery is cooled.

[0074] The usage form of the heat exchanger of the present embodiment is not particularly limited, and it can be used alone or in two or more. When used alone, as described above, the member to be heat-exchanged is brought into contact with the upper and lower surfaces of the heat exchanger for use. When used in two, for example, the member to be heat-exchanged can be disposed so as to be sandwiched between two heat exchangers for use. Further, when used in two or more, the heat exchanger and the member to be heat-exchanged can be disposed so as to be alternately stacked for use.

[0075] As described above, according to the heat exchanger of the present embodiment, since the heat transfer layers 51 and 61 in the outer laminate material L1 of the outer package 1 and the inner core laminate material L2 of the inner fin 2 are formed of titanium foil with excellent corrosion resistance, the corrosion resistance can be improved and high reliability can be obtained. That is, when the heat fusion layer 52 and 62 of the outer package 1 and the inner fin 2 partially flow out due to the pressure during heat fusion during the manufacture of the heat exchanger, or when the laminate materials L1 and L2 are cut, the heat transfer layers 51 and 61 are exposed. Therefore, moisture such as cooling water may come into contact with the heat transfer layers 51 and 61. However, even in such a case, since the titanium foil constituting the heat transfer layers 51 and 61 has excellent corrosion resistance, corrosion deterioration of the heat transfer layers 51 and 61 can be effectively prevented. Therefore, liquid leakage and partial bulging deformation due to corrosion deterioration of the heat transfer layers 51 and 61 can be prevented, and high reliability can be surely obtained. In particular, when annealed foil of pure titanium of grade 1 of ASTM B265 is used as the heat transfer layers 51 and 61, the corrosion resistance can be further improved and higher reliability can be obtained.

[0076] Also, in the present embodiment, since the inner fin 2 having a square wave shape is used, the bottom wall of the concave portion and the top wall of the convex portion are flat, and the contact area with the pair of opposing walls 111 and 151 of the outer package 1 can be increased. Therefore, the heat transfer performance between the inner fin 2 and the outer package 1 can be further improved, and the heat exchange performance can be further improved. Furthermore, since a large contact area between the inner fin 2 and the outer package 1 can be ensured, the mounting strength of the inner fin 2 to the outer package 1 can be improved, and the occurrence of poor contact and the like can be more surely prevented.

[0077] Also, in this embodiment, since the inner fins 2 are formed in a square wave shape, a large number of rising walls connecting the bottom wall of the recess and the top wall of the convex portion are arranged in a state orthogonal to the opposing upper and lower walls 111 and 151 of the outer package 1. Therefore, the inner fins 2 can fully exhibit the function as a reinforcing member. For example, they act to stretch against the compressive stress in the compression direction due to external pressure and act to pull against the tensile stress in the expansion direction due to internal pressure. Thus, high strength can be ensured against both internal and external pressures, deformation can be prevented, and a stable shape can be reliably maintained, further improving the operation reliability. In particular, when multiple heat exchangers are stacked and used, sufficient pressure resistance can be ensured, a stable form (shape) can be reliably maintained, and high heat exchange performance can be surely obtained. Moreover, since sufficient pressure resistance can be ensured, there is no need to separately provide a reinforcing member, and accordingly, the number of parts can be reduced, and the structure can be simplified and the cost can be reduced.

[0078] Also, according to the heat exchanger of this embodiment, since the tray member 10, the cover member 15, the inner fins 2, and the header 3 as constituent members are made based on synthetic resin, they can be easily manufactured by simply thermally fusing the constituent members as appropriate. Therefore, the heat exchanger of this embodiment can reduce costs and improve productivity compared to conventional metal heat exchangers manufactured by joining processes such as brazing, which are difficult and cumbersome.

[0079] Furthermore, different from the case of using troublesome and restricted metal processing such as metal plastic processing and cutting processing, the heat exchanger of this embodiment can further improve production efficiency and reduce costs.

[0080] Also, since the heat exchanger of this embodiment is formed by laminating the tray member 10 and the cover member 15 made of a thin laminate material L1, sufficient thinning and weight reduction can be surely achieved.

[0081] Furthermore, since the outer package 1 of the heat exchanger of the present embodiment is a laminate material L1, the shape and size of the heat exchanger itself can be easily changed, and as described above, the thickness, strength, heat exchange performance, etc. can also be easily changed. Therefore, it can be easily finished into an appropriate configuration according to the heat exchanger mounting position, etc., increasing the degree of freedom in design and improving the versatility.

[0082] In the above embodiment, as the cover member 15 of the outer package 1, an unformed sheet-like member is used, but it is not limited thereto. In the present invention, the cover member 15 may be subjected to a forming process. For example, the cover member may be constituted by a formed product having a hat-shaped cross section with a central portion recessed upward, and the hat-shaped cover member may be integrally joined at its outer peripheral edge portion so as to cover the tray-shaped tray member 10 as described above from above to form an outer package.

Example

[0083]

Table 1

[0084] <Example 1> (1) Preparation of outer package laminate material L1 As shown in Table 1, as the metal foil for the heat transfer layer 51 of the outer package laminate material (outer package material) L1 of Example 1, a titanium foil with a thickness of 120 μm, which is an annealed foil of pure Ti (pure titanium) of grade 1 of ASTM B265, was prepared. This titanium foil was used as the heat transfer layer 51, and a 40-μm thick unstretched polypropylene (CPP) film was laminated on one surface (inner surface) thereof via a urethane-based adhesive (thickness 3 μm), and a 12-μm thick polyethylene terephthalate (PET) film was laminated on the other surface (outer surface) of the heat transfer layer (aluminum foil) via a urethane-based adhesive (thickness 3 μm) to produce an outer package laminate material L1.

[0085] (2) Preparation of inner core laminate material L2 As shown in Table 1, a pure titanium foil similar to the above was prepared as the metal foil for the heat transfer layer 61 of the core laminate material (core material) L2 of Example 1. Using this titanium foil as the heat transfer layer 61, a 40-μm-thick unstretched polypropylene (CPP) film was laminated on both sides thereof via a urethane-based adhesive (thickness: 3 μm) to produce the core laminate material L2.

[0086] (3) Production of the tray member 10 and the cover member 15 Based on the embodiment shown in FIGS. 1 to 3, a sheet material obtained by cutting the above outer package laminate material L1 was subjected to deep drawing using a press die to produce a tray member 11 having a recess 11 with a width (Wr) of 90 mm × a length (Lr) of 140 mm × a depth (Dr) of 4 mm and a flange portion 12 with a width (Wf) of 10 mm formed on the entire circumference of the opening edge of the recess 11, as shown in FIGS. 6 and 7.

[0087] In this example, in order to obtain high dimensional accuracy, a tray member 10 processed into a sharp shape was produced. Specifically, the corner radius (R1) at the four corners of the recess 11 is 2.0 mm, the die shoulder radius (R2) is 1.0 mm, the punch shoulder radius (R3) is 1.0 mm, and the clearance between the die and the punch is 0.25 mm.

[0088] Also, the above outer package laminate material L1 was cut to produce a sheet-like cover member 15 having a size (110 mm × 160 mm) corresponding to the upper surface of the tray member 11, with entrances and exits 16 (see FIGS. 1 to 3) formed corresponding to both sides of the recess 11 of the tray member 11.

[0089] (4) Production of the inner fin 2 The above inner core laminate L2 was formed into a square wave shape with a fin height (Hf) of 4.1 mm, a fin pitch (Pf) of 4 mm, and a fin thickness (Tf) of 0.2 mm by a gear embossing machine as shown in Fig. 5, and the square wave sheet was cut into a length of 100 mm × a width of 90 mm to produce the inner fin 2. Note that the ridge direction and valley direction of the inner fin 2 are arranged along the length direction (vertical direction). Further, also in the inner fin 2, in order to make it a sharp shape similar to the tray member 11, the outer corner radius (R4) was set to 0.5 mm.

[0090] (5) Production of the header 3 As shown in Figs. 2 and 3, by injection molding a resin material made of PP, a header 3 in which a pipe portion 33 with an inner diameter of φ10 mm, an outer diameter of φ12 mm, and a length of 3 mm was integrally formed on a mounting box portion 31 with a height of 4 mm × a length of 90 mm × a width of 20 mm was produced.

[0091] (6) Assembly of the heat exchanger Using the outer package 1, the inner fin 2, and the header 3 produced in Example 1, the heat exchanger of Example 1 was produced. That is, the headers 3, 3 were accommodated at both ends in the recessed portion 11 of the tray member 10 with each pipe portion 33 facing upward. Further, the above inner fin 2 was accommodated between the headers 3, 3 in the recessed portion 11.

[0092] Next, the cover member 15 was arranged on the tray member 10 so as to close the recessed portion 11 from above. At this time, the pipe portions 33, 33 of the headers 3, 3 were inserted through the entrances and exits 16, 16 of the cover member 15 and projected above the cover member 15.

[0093] In this way, a non-joined heat exchanger temporary assembly was produced, and for the temporary assembly, using upper and lower seal molds that conform to the shape of the temporary assembly, the joint portions between the respective components in the temporary assembly were thermally adhered (heat fused) under the following two seal conditions A and B to produce two types of heat exchangers of Example 1 with different seal conditions.

[0094] Sealing condition A was 190 °C × 0.3 MPa × 7 seconds, and a one-stage heat seal (one-stage fusion treatment) was performed to fabricate a heat exchanger under sealing condition A.

[0095] Sealing condition B was 220 °C × 0.4 MPa × 14 seconds, and a one-stage heat seal (one-stage fusion treatment) was performed to fabricate a heat exchanger under sealing condition B.

[0096] <Example 2> An inner core laminate L2 was fabricated in the same manner as in Example 1 above, except that an Fe (iron) foil with a thickness of 120 μm of SPCC-S (standard quality) defined in JIS G3141 was used as the metal foil for the heat transfer layer 61 of the inner core laminate L2. The inner core laminate L2 was processed in the same manner as in Example 1 to fabricate the inner fin 2 of Example 2.

[0097] A heat exchanger of Example 2 was fabricated in the same manner as in Example 1 above, except that the inner fin 2 of Example 2 was used.

[0098] <Example 3> An outer package laminate L1 was fabricated in the same manner as in Example 1 above, except that an aluminum (Al) foil with a thickness of 120 μm of A4160-O defined in JIS H4160 was used as the metal foil for the heat transfer layer 51 of the outer package laminate L1. The outer package laminate L1 was processed in the same manner as in Example 1 to fabricate the tray member 10 and the cover member 15 of Example 3.

[0099] A heat exchanger of Example 3 was fabricated in the same manner as in Example 1 above, except that the tray member 10 and the cover member 15 of Example 3 were used.

[0100] <Comparative Example 1> A heat exchanger of Comparative Example 1 was fabricated in the same manner as in Example 1 above, except that a tray member similar to that of Example 3 and the cover member 15, and the inner fin 2 similar to that of Example 2 were used.

[0101] <Evaluation Test of Tray Formability> In Examples 1 to 3 and Comparative Example 1, the moldability of the tray member 10 before assembling the heat exchanger was evaluated.

[0102] That is, for the tray member (molded product) 10, in a dark room, the inside of the tray member was illuminated, and the presence or absence of light transmission near the corner portion of the tray member was checked, and the presence or absence of pinholes and cracks was visually inspected. As a result, those without the occurrence of pinholes and cracks were evaluated as "○ (good)", and those with the occurrence of pinholes and cracks were evaluated as "× (bad)". The evaluation results are shown in Table 1.

[0103] As is clear from Table 1, the moldability was good in any of the tray members of Examples 1 to 3 and Comparative Example 1.

[0104] <Evaluation Test of Pressure Resistance> In Examples 1 to 3 and Comparative Example 1, three heat exchangers (N = 3) were prepared for each of the sealing conditions A and B, and an evaluation test of pressure resistance was performed on each heat exchanger. That is, cooling water was circulated through each heat exchanger, and after holding at an internal pressure of 1 MPa for 5 minutes, the presence or absence of peeling (adhesive failure location) between the outer package 1 and the inner fin 2 was observed in each heat exchanger. As a result, those without the occurrence of adhesive failure locations such as peeling and swelling were evaluated as "○ (good)", and those with the occurrence of adhesive failure locations such as peeling and swelling were evaluated as "× (bad)". The evaluation results are shown in Table 1.

[0105] As is clear from Table 1, the pressure resistance was good in any of the heat exchangers of Examples 1 to 3 and Comparative Example 1, regardless of the sealing conditions A and B.

[0106] <Evaluation Test of Corrosion Resistance (OY Water Corrosion Test)> In the heat exchangers of Examples 1 to 3 and Comparative Example 1, for each heat exchanger under different sealing conditions A and B, OY water at 60 °C was passed through at a rate of 3 L / min for 250 hours, and then the corrosion state of each heat exchanger was observed.

[0107] The composition of the OY water is Cl - : 200 ppm, SO42- : 60 ppm, Fe 3+ : 30 ppm, Cu 2+ : 1 ppm, Na + : It is 120 ppm.

[0108] As a result of the observation, those in which no corrosion occurred were rated as "◎ (excellent)", those in which discoloration of the metal foil due to corrosion was observed in at least one of the outer package 1 and the inner fin 2 were rated as "○ (good)", and those in which liquid leakage occurred in the heat exchanger due to corrosion were rated as "× (poor)". The results are shown in Table 1.

[0109] As is clear from Table 1, the heat exchangers of Examples 1 to 3 were superior in corrosion resistance to the heat exchanger of Comparative Example 1, and in particular, the heat exchanger of Example 1 had very excellent corrosion resistance.

[0110] In terms of corrosion resistance, similar evaluation results were obtained for each example and comparative example regardless of the seal conditions A and B.

Explanation of symbols

[0111] 1: Outer package 111: Bottom wall (opposing wall) 151: Upper wall (opposing wall) 16: Inlet / outlet 2: Inner fin 25: Recess 26: Protrusion 51: Heat transfer layer 52: Heat fusion layer 61: Heat transfer layer 62: Heat fusion layer L1: Outer package laminate material L2: Inner core laminate material

Claims

1. A heat exchanger comprising an outer casing provided with an inlet and an outlet, wherein a heat exchange medium flowing in from the inlet passes through the inside of the outer casing and flows out from the outlet, the outer casing is composed of an outer casing laminate material provided with a heat-fused resin layer at least on the inner surface side of a metal heat transfer layer, the heat transfer layer of the outer casing is composed of titanium having excellent corrosion resistance, characterized in that it is a heat exchanger.

2. The heat exchanger according to claim 1, wherein the titanium constituting the heat transfer layer of the outer casing is grade 1 of ASTM B265.

3. An inner fin having uneven portions is disposed inside the outer casing, the inner fin is composed of an inner core laminate material provided with heat-fused layers on both sides of a metal heat transfer layer, The heat exchanger according to claim 1 or 2, wherein the heat transfer layer of the inner fin is composed of titanium having excellent corrosion resistance.

4. A heat exchanger comprising an outer casing provided with an inlet and an outlet, and an inner fin disposed inside the outer casing and having uneven portions, wherein a heat exchange medium flowing in from the inlet passes through the inside of the outer casing and flows out from the outlet, the outer casing is composed of an outer casing laminate material provided with a heat-fused resin layer at least on the inner surface side of a metal heat transfer layer, the inner fin is composed of an inner core laminate material provided with heat-fused layers on both sides of a metal heat transfer layer, The heat exchanger is characterized in that the heat transfer layer of the inner fin is composed of titanium having excellent corrosion resistance.

5. The heat exchanger according to claim 3 or 4, wherein the titanium constituting the heat transfer layer of the inner fin is grade 1 of ASTM B265.

6. The outer package has a pair of opposing walls, and the inner fin is disposed between the pair of opposing walls. The heat exchanger according to any one of claims 3 to 5, wherein the inner fin has a bottom wall of the recess and a top wall of the protrusion disposed parallel to the pair of opposing walls, and a rising wall connecting between the bottom wall of the recess and the top wall of the protrusion is formed in a square wave shape orthogonal to the pair of opposing walls.

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