JP7693288B2 - heat exchanger - Google Patents

Description

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

In the present invention, the term "titanium (Ti)" is used to include "titanium alloys (Ti alloys)."

As electronic devices such as smartphones and personal computers become smaller and more powerful, measures to prevent heat generation around the CPU of the electronic device have become important. Some models incorporate water-cooled coolers and heat pipes to reduce the thermal load on electronic components such as the CPU and prevent heat from building up inside the housing, and technologies have been proposed to avoid the adverse effects of heat.

In addition, the battery modules installed in electric and hybrid vehicles generate a lot of heat in the battery packs due to repeated charging and discharging. For this reason, technology has been proposed to incorporate water-cooled coolers and heat pipes into battery modules, just like the electronic devices mentioned above, to avoid the adverse effects of heat.

In addition, measures such as installing cooling plates or heat sinks have been proposed to prevent heat generation in power modules made of silicon carbide (SiC) and other materials.

Conventionally, thin coolers such as heat pipes built into small electronic devices have mainly been made of metal, with multiple metal components joined by brazing or other methods (Patent Documents 1 to 3).

Since each component of such metal coolers is manufactured using laborious metal processing (machining), such as plastic processing, such as casting or forging, or removal processing, such as cutting, it is difficult to make them any thinner than they are currently.

A cooler has been proposed in which the outer casing and inner fin (inner core material) are made of laminate material. The laminate material is made by laminating a heat-sealed resin layer onto a metal foil layer, and the heat-sealed layer of the laminate material for the outer casing is heat-sealed (thermally fused) to the heat-sealed layer of the laminate material for the inner fin to form the cooler.

Coolers made from laminated materials have been attracting attention in recent years because they do not require tedious metal processing, are easier to manufacture, reduce costs, and are thinner.

JP 2015-59693 A JP 2015-141002 A JP 2016-189415 A

In light of this technical background, heat exchangers using laminated materials have sufficient corrosion resistance when the metal foil layer in the outer casing and inner fins is securely covered with a resin layer. However, pressure during heat fusion can cause the heat fusion layer (resin layer) to partially flow out of the metal foil layer, exposing the metal foil layer. This can lead to corrosion degradation due to contact with moisture such as cooling water. In addition, the outer casing and inner fins are manufactured by cutting the laminated material, and the metal foil layer can be exposed at the cut edges, which can lead to corrosion degradation similar to that described above when the exposed metal foil layer comes into contact with moisture such as cooling water.

When the metal foil layer corrodes and deteriorates in this way, problems arise in that the corroded and deteriorated parts may cause liquid leakage, swelling, deformation, etc., resulting in reduced reliability.

This invention was made in consideration of the above problems, and aims to provide a heat exchanger using a laminate material that can prevent corrosion deterioration of the heat transfer layer, prevent liquid leakage and swelling deformation, and achieve high reliability.

To solve the above problems, the present invention provides the following:

[1] A heat exchanger comprising an outer envelope having an inlet and an outlet, wherein a heat exchange medium flowing in from the inlet passes through the outer envelope and flows out from the outlet,
The outer envelope is made of an outer envelope laminate material having a resin heat-sealing layer provided on at least the inner side of a metal heat-transfer layer,
13. A heat exchanger comprising: a heat transfer layer of said outer casing, said heat transfer layer being made of titanium;

[2] A heat exchanger as described in the preceding paragraph 1, in which the titanium constituting the heat transfer layer of the outer casing is grade 1 according to ASTM B265.

[3] An inner fin having an uneven portion is disposed inside the outer casing,
The inner fin is made of an inner core laminate material having a heat fusion layer on both sides of a metal heat transfer layer,
3. The heat exchanger according to claim 1 or 2, wherein the heat transfer layer of the inner fin is made of titanium.

[4] A heat exchanger comprising an outer envelope having an inlet and an outlet, and an inner fin disposed inside the outer envelope and having an uneven portion, in which a heat exchange medium flowing in from the inlet passes through the outer envelope and flows out from the outlet,
The outer envelope is made of an outer envelope laminate material having a resin heat-sealing layer provided on at least the inner side of a metal heat-transfer layer,
The inner fin is made of an inner core laminate material having a heat fusion layer on both sides of a metal heat transfer layer,
13. A heat exchanger comprising: a heat transfer layer of the inner fin;
[5] The heat exchanger according to the preceding paragraph 3 or 4, wherein titanium constituting the heat transfer layer of the inner fin is grade 1 according to ASTM B265.

[6] The outer envelope has a pair of opposing walls, and the inner fin is disposed between the pair of opposing walls,
6. 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 arranged parallel to the pair of opposing walls, and a rising wall connecting the bottom wall of the recess and the top wall of the protrusion is formed in an angular waveform perpendicular to the pair of opposing walls.

According to the heat exchanger of the invention [1], the heat transfer layer of the outer casing is made of titanium, which has excellent corrosion resistance. Therefore, even if the heat transfer layer of the outer casing is exposed and comes into contact with moisture, the heat transfer layer can be effectively prevented from corroding and deteriorating, and liquid leakage and swelling caused by the corrosion can be prevented, resulting in high reliability.

The heat exchanger of invention [2] uses titanium, a unique material with even better corrosion resistance, as the heat transfer layer of the outer casing, so corrosion deterioration can be prevented more reliably.

According to the heat exchangers of inventions [3] and [4], the heat transfer layer of the inner fin is made of titanium, which has excellent corrosion resistance. Therefore, even if the heat transfer layer of the inner fin is exposed and comes into contact with moisture, the heat transfer layer can be effectively prevented from corroding and deteriorating, and leakage and swelling caused by the corrosion can be prevented, resulting in high reliability.

The heat exchanger of the invention [5] uses titanium, a unique material with even better corrosion resistance, as the heat transfer layer of the inner fin, so corrosion deterioration can be prevented even more reliably.

According to the heat exchanger of the invention [6], the inner fins are formed in a rectangular wave shape, so that the bottom walls of the recesses and the top walls of the protrusions of the inner fins are flat, and the contact area with the outer casing can be increased. This improves the heat transfer between the inner fins and the outer casing, and improves the heat exchange performance.

FIG. 1 is a perspective view showing a heat exchanger according to an embodiment of the present invention. FIG. 2 shows a heat exchanger of the embodiment, in which FIG. 2(a) is a plan view, FIG. 2(b) is a side cross-sectional view corresponding to the cross section along line B-B in FIG. 2(a), and FIG. 2(c) is a front cross-sectional view corresponding to the cross section along line C-C in FIG. FIG. 3 is an exploded perspective view of the heat exchanger according to the embodiment. FIG. 4 is a front cross-sectional view for explaining an outer shell and an inner fin applied to the heat exchanger of the embodiment. FIG. 5 is a front cross-sectional view for explaining the inner fin of the embodiment. FIG. 6 is a plan view showing a tray member employed in a heat exchanger according to an embodiment of the present invention. 7 is a cross-sectional view of an end portion of a tray member according to an embodiment of the present invention.

Figures 1 to 3 are diagrams showing a heat exchanger according to an embodiment of the present invention. In the following explanation, to facilitate understanding of the invention, the left-right direction in Figure 2(a) will be referred to as the "front-rear direction", and the up-down direction in Figure 2(b) will be referred to as the "up-down direction (thickness direction)".

As shown in Figures 1 to 3, the heat exchanger of this embodiment is used as a heat transfer panel, a heat transfer tube, etc., and includes an outer envelope 1 as a casing (container), an inner fin (inner core material) 2 housed inside the outer envelope 1, and a pair (both sides) of headers (joint members) 3, 3 housed within both ends of the outer envelope 1.

The outer packaging body 1 is composed of a tray member 10 that is rectangular in plan view and a cover member 15 that is rectangular in plan view.

The tray member 10 is made of a molded product of the outer laminate material L1, and the entire intermediate region except for the outer periphery is recessed downward using a cold forming method such as deep drawing or extrusion molding to form a recessed portion 11 that is rectangular in plan view, and an outwardly protruding flange portion 12 is integrally formed on the outer periphery of the opening edge of the recessed portion 11.

The cover member 15 also has a pair of openings 16, 16 formed in correspondence with the front and rear ends of the recessed portion 11 in the tray member 10. Needless to say, in this embodiment, one of the pair of openings 16 is configured as an entrance, and the other opening 16 is configured as an exit.

The tray member 10 and the cover member 15 are made of an outer laminate material L1, which is a laminate sheet or film that is flexible and pliable.

As shown in FIG. 4, the outer laminate material L1 includes a heat transfer layer 51 made of metal (metal foil), a heat fusion layer 52 made of a heat-sealable resin film or a heat-sealable resin sheet laminated via an adhesive on one side (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 side (outer surface) of the heat transfer layer 51. In this embodiment, the term "foil" is used to include a film, a thin plate, and a sheet.

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

In this embodiment, by using the above-mentioned titanium foil as the heat transfer layer 51 of the outer laminate material L1, the corrosion resistance of the heat transfer layer 51 can be improved, and the corrosion resistance of the outer laminate material L1, i.e., the outer envelope 1, can be improved.

The heat transfer layer 51 is also called a heat collection layer, and is preferably 30 μm to 200 μm thick, more preferably 40 μm to 180 μm thick. In other words, if the heat transfer layer 51 is too thin, it is likely to be easily deformed by external pressure and its strength may decrease, which is not preferable. Conversely, if the heat transfer layer 51 is too thick, it is likely to be less flexible and its moldability may decrease, which is not preferable.

In addition, by subjecting the heat transfer layer 51 to a surface treatment such as chemical conversion treatment, the durability of the heat transfer layer 51 can be further improved, such as by preventing corrosion of the heat transfer layer 51 and improving adhesion to the resin.

As the heat-sealing layer 52, a film or sheet made of a polyolefin resin such as polyethylene or polypropylene, or a modified resin thereof, a fluorine-based resin, a polyester-based resin, a polyvinyl chloride resin, or the like can be suitably used.

It is preferable to use a thermal adhesive layer 52 with a thickness of 20 μm to 500 μm.

The heat-sealing layer 52 can be preferably made of non-oriented polypropylene (CPP) having a thickness of 20 μm to 500 μm, more preferably 30 μm to 80 μm, and is made of a three-layer (random PP/block PP/random PP) co-extruded film.

The protective layer 53 can be preferably a film or sheet of oriented polyester resin (PET, PBT, etc.), oriented polyamide resin (ONY), etc., whose melting point is 10°C or higher, more preferably 20°C or higher, than the heat-sealing layer 52.

Furthermore, it is preferable to use a protective layer 53 with a thickness of 6 μm to 100 μm.

As an adhesive for bonding between the heat transfer layer 51, heat fusion layer 52, and protective layer 53 that constitute the outer laminate material L1, a urethane adhesive, epoxy adhesive, olefin adhesive, or the like having a thickness of 1 μm to 5 μm can be suitably used.

In this embodiment, a three-layered sheet is used as the laminate material L1 constituting the outer envelope 1, but this is not limited thereto. In the present invention, a two-layered sheet consisting of a heat transfer layer and a heat fusion layer may be used, or a sheet having four or more layers may be used. When using a sheet having 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 fusion layer, so that the sheet has four or more layers.

The tray member 10 and cover member 15 of the outer envelope 1 are formed from the outer envelope laminate material L1 configured as described above. The cover member 15 is then attached to the tray member 10 so as to close the opening of the recessed portion 11, as will be described in detail later, thereby forming the outer envelope 1.

In this embodiment, a pair of opposing walls 111, 151 is 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 of the cover member 15 attached to the tray member 10 that corresponds to the recessed portion 11.

As shown in Figures 1 to 4, the inner fin 2 housed in the hollow portion (recessed portion) 11 of the outer envelope 1 is made of an inner core laminate material L2, which is a laminate sheet or film having flexibility or flexibility.

As shown in FIG. 4, the inner core laminate material L2 includes a heat transfer layer 61 made of 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 with an adhesive.

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

In this embodiment, by using the above-mentioned 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, i.e., the inner fin 2, can be improved.

The heat transfer layer 61 should preferably have a thickness of 30 μm to 200 μm, and more preferably 40 μm to 180 μm. In other words, if the heat transfer layer 61 is too thin, it may be easily deformed by external pressure and its strength may decrease, which is not preferable. Conversely, if the heat transfer layer 61 is too thick, it may be less flexible and its moldability may decrease, which is not preferable.

As the heat-sealing layer 62, a film or sheet made of a polyolefin resin such as polyethylene or polypropylene, or a modified resin thereof, a fluorine-based resin, a polyester resin, a vinyl chloride resin, or the like can be suitably used. Among these, it is particularly preferable to use a film or sheet made of non-oriented polypropylene (CPP).

The thermal adhesive layer 62 should preferably have a thickness of 20 μm to 5000 μm, and more preferably 30 μm to 80 μm.

In this embodiment, a three-layered sheet is used as the laminate material L2 that constitutes the inner fin 2, but this is not limited thereto, and a four-layered or more sheet may be used in the present invention. For example, a four-layered or more sheet may be used by interposing another layer between the heat-sealing layer and the heat transfer layer.

The processing method for the inner fin 2 is not particularly limited, but an example is a method in which the inner core laminate material L2 is sandwiched between a pair of embossing rolls or a pair of corrugated rolls and passed between the pair of rolls to form the unevenness. Another example is a method in which a press machine or a press die is used to form the unevenness in the inner core laminate material L2.

As shown in Figures 2 to 5, the inner fin 2 is formed in a rectangular wave shape (a digital signal waveform) in which the recesses 25 and protrusions 26 are alternately and continuously formed. That is, the bottom surface (bottom wall) of the recesses and the top surfaces (top walls) of the protrusions in the inner fin 2 of this embodiment are formed flat, and 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 when assembled into a heat exchanger. Furthermore, the inner fin 2 has a rising wall connecting adjacent recess bottom walls and protrusion top walls arranged perpendicular to the recess bottom wall and protrusion top wall, or to the upper and lower walls 111, 151 of the outer casing 1 when assembled into a heat exchanger.

In this embodiment, an inner fin 2 having an angular waveform is used, but the present invention is not limited to this. In the present invention, an inner fin having a general waveform (sine wave shape) in which arc-shaped concave and convex portions are alternately formed in succession, i.e., an analog signal waveform, may also be used. However, in the present invention, the inner fin may have any shape as long as it has concave and convex portions that are joined to the inner surface of the outer envelope.

The inner fin 2 is accommodated in the recess 11 of the tray member 10. In this case, the inner fin 2 is accommodated in the middle part of the recess 11 of the tray member 10, excluding both front and rear ends. Furthermore, the inner fin 2 is arranged so that its ridge and valley directions coincide with the front-rear direction of the tray member 10 (left-right direction in FIG. 1). As a result, the tunnel and groove parts formed by the ridge and valley parts 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 multiple channels are arranged in parallel in the width direction (left-right direction), so that the heat exchange medium (heat medium) can flow smoothly from one end side to the other end side in the front-rear direction of the outer envelope 1 while being evenly distributed through each heat exchange channel.

On the other hand, as shown in Figures 2 and 3, a pair of headers 3, 3 arranged at both ends of the outer envelope 1 are made of molded synthetic resin.

It is preferable to use the same type of resin as that used to form the heat-sealing layers 52, 62 of the outer envelope 1 and the inner fin 2 as the resin used to form the header 3. Specifically, polyolefin resins such as polyethylene and polypropylene or modified resins thereof, fluorine-based resins, polyester-based resins, polyvinyl chloride resins, etc. can be preferably used.

The header 3 comprises a box-shaped mounting box 31 having an opening 32 on one side, and a pipe section 33 provided on the upper wall of the mounting box 31. The pipe section 33 is connected to the inside of the mounting box 31, and is configured so that a heat exchange medium can pass between the inside of the pipe section 33 and the inside of the mounting box 31.

The method for molding the header 3 is not particularly limited, but a molding method using injection molding, for example, can be preferably used.

The mounting box portion 31 of the header 3 is disposed on both sides of the inner fin 2 in the recessed portion 11 of the tray member 10. Furthermore, the pipe portion 33 of the header 3 is disposed facing upward, and the opening portion 32 of the mounting box portion 31 is disposed facing inward, i.e., facing the inner fin 2.

In this way, the headers 3, 3 are housed in the tray member 10, and the cover member 15 is placed 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 placed inside the entrance/exit 16 of the cover member 15.

The heat exchanger assembly thus temporarily assembled is heated, and the contacting parts are thermally fused together to form an integrated unit.

In this heat fusion process, first, the overlapping portion between the flange portion 12 of the tray member 10 and the outer peripheral edge portion of the cover member 15 in the outer envelope 1 is heated while being sandwiched between a pair of upper and lower heat seal dies (outer envelope fusion process). This heat fusion (thermal adhesion) is performed between 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, and the hollow portion of the outer envelope 1 is sealed in an airtight or liquid-tight state.

Next, the middle region (lower wall 111 and upper wall 151) of the outer casing 1 with the outer periphery heat-sealed is sandwiched between a pair of upper and lower heating plates and heated. As a result, the heat-sealed layer 62 at the peak and valley bottom of the inner fin 2 and the heat-sealed layer 52 at the bottom wall 111 of the tray member 10 and the middle region (upper wall) 151 of the cover member 15 are bonded together by heat adhesion (heat fusion) to form a liquid-tight or airtight seal (fin fusion process). Furthermore, in this fin fusion process, the outer periphery of the mounting box portions 31, 31 of the headers 3, 3 and the heat-sealed layer 52 of the corresponding tray member 10 and cover member 15 are bonded together by heat adhesion (heat adhesion) to form a liquid-tight or airtight seal.

The heat exchanger thus assembled is positioned so that the pipe sections 33, 33 of the headers 3, 3 protrude upward from the upper walls (cover members 15) at both ends of the outer envelope 1.

Here, if the heat-sealed parts between the inner fin 2 and the header 3, 3 and the outer envelope 1 are made of the same type of resin, they can be securely fixed together with sufficient mounting strength.

In this embodiment, by performing the heat fusion process (heating process) under reduced pressure, strong heat bonding can be performed with high 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 headers 3, 3 that are in contact with them, and the bonding area can be made large. Therefore, it is preferable to perform the heat fusion process under reduced pressure.

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

In addition, in this embodiment, the outer envelope fusion process, which heat-seals the flange portion 12 of the tray member 10 to the outer peripheral edge portion of the cover member 15, and the fin fusion process, which heat-seals the inner fin 2 and the headers 3, 3 to the outer envelope 1, are performed by separate heat treatments, but this is not limited to this, and in the present invention, the outer envelope fusion process and the fin fusion process may be performed by the same heat treatment (one-stage heat fusion process).

In addition, in this embodiment, during the fusion process, particularly the fin fusion process, a heat-conductive rubber layer is placed on the contact surface between the outer envelope 1 and the pair of heating plates that sandwich the lower wall 111 and upper wall 151 of the outer envelope 1. This ensures that the lower wall 111 and upper wall 151 of the outer envelope 1 come into contact with the bottom surface of the recess and the top surface of the protrusion of the inner fin 2, allowing the heat fusion process to be performed with high precision.

The heat exchanger having the above configuration is used as a cooler (cooling device) for cooling a battery or the like as a cooling target member (heat exchange target member). That is, an inlet pipe for introducing a cooling liquid (cooling water, antifreeze, etc.) as a heat exchange medium (refrigerant) is connected to one pipe section 33 of the heat exchanger, and an outlet pipe for discharging the cooling liquid is connected to the other pipe section 33. Furthermore, a battery as a cooling target member is placed in contact with the lower wall 111 and/or the upper wall 151 of the outer casing 1 of the heat exchanger. In this state, the cooling liquid flows from one pipe section 33 into the inside of the outer casing 1 through one header 3, flows through the inner fin 2, and flows out of the other pipe section 33 through the other header 3. By circulating the cooling liquid in the outer casing 1 in this way, heat is exchanged between the cooling liquid and the battery through the inner fin 2 and the upper and lower walls of the outer casing 1, and the battery is cooled.

The heat exchanger of this embodiment is not particularly limited in the manner of use, and may be used alone or in combination of two or more. When using one, as described above, the heat exchanger is used by contacting the upper and lower surfaces of the heat exchanger with the heat exchange target material. When using two, for example, the two heat exchangers may be arranged to sandwich the heat exchange target material. Furthermore, when using two or more, the heat exchangers and the heat exchange target material may be arranged to overlap each other.

As described above, according to the heat exchanger of this embodiment, the heat transfer layers 51, 61 in the outer laminate material L1 of the outer envelope 1 and the inner core laminate material L2 of the inner fin 2 are made of titanium foil with excellent corrosion resistance, so that corrosion resistance can be improved and high reliability can be obtained. That is, when the heat fusion layers 52, 62 of the outer envelope 1 and the inner fin 2 are partially leaked due to pressure during heat fusion during the manufacture of the heat exchanger, or when the laminate materials L1, L2 are cut, the heat transfer layers 51, 61 are exposed, so that moisture such as cooling water may come into contact with the heat transfer layers 51, 61. Even in such cases, however, since the titanium foil constituting the heat transfer layers 51, 61 has excellent corrosion resistance, corrosion deterioration of the heat transfer layers 51, 61 can be effectively prevented. Therefore, liquid leakage and partial swelling deformation due to corrosion deterioration of the heat transfer layers 51, 61 can be prevented, and high reliability can be reliably obtained. In particular, when using annealed foil of pure titanium of grade 1 conforming to ASTM B265 as the heat transfer layers 51 and 61, corrosion resistance can be further improved, resulting in higher reliability.

In addition, in this embodiment, because an inner fin 2 with a rectangular waveform is used, the bottom wall of the recess and the top wall of the protrusion are flat, and the contact area with the pair of opposing walls 111, 151 of the outer envelope 1 can be increased. This further improves the heat transfer between the inner fin 2 and the outer envelope 1, and further improves the heat exchange performance. Furthermore, because a large contact area between the inner fin 2 and the outer envelope 1 can be secured, the attachment strength of the inner fin 2 to the outer envelope 1 can be improved, and the occurrence of poor contact and the like can be more reliably prevented.

In addition, in this embodiment, since the inner fin 2 is formed in an angular wave shape, many rising walls connecting the bottom wall of the recess and the top wall of the protrusion are arranged perpendicular to the opposing upper and lower walls 111, 151 of the outer envelope 1. As a result, the inner fin 2 can fully function as a reinforcing member, for example, it acts to brace against stress in the compressive direction due to external pressure and acts to pull against stress in the expanding direction due to internal pressure, so that high strength can be ensured against both internal and external pressure, deformation can be prevented, a stable shape can be reliably maintained, and operational reliability can be further improved. In particular, when multiple heat exchangers are used in a stacked manner, sufficient pressure resistance can be ensured, a stable form (shape) can be reliably maintained, and high heat exchange performance can be reliably obtained. Furthermore, since sufficient pressure resistance can be ensured, there is no need to provide a separate reinforcing member, and the number of parts can be reduced accordingly, simplifying the structure and reducing costs.

In addition, according to the heat exchanger of this embodiment, the tray member 10, cover member 15, inner fin 2, and header 3 as components are made from synthetic resin, so they can be easily manufactured by simply heat fusing each component appropriately. Therefore, the heat exchanger of this embodiment can reduce costs and improve productivity compared to conventional metal heat exchangers that are manufactured using difficult and tedious joining processes such as brazing.

Furthermore, the heat exchanger of this embodiment can further improve production efficiency and reduce costs, unlike those that use tedious and restrictive metal processing such as metal plastic processing and cutting.

In addition, the heat exchanger of this embodiment is formed by bonding together a tray member 10 and a cover member 15 made of a thin laminate material L1, so it can be reliably made sufficiently thin and lightweight.

Furthermore, in the heat exchanger of this embodiment, since the outer casing 1 is made of laminate material L1, the shape and size of the heat exchanger itself can be easily changed, and as mentioned above, the thickness, strength, heat exchange performance, etc. can also be easily changed, so that the heat exchanger can be easily finished into an appropriate configuration according to the installation position, etc., which increases the freedom of design and improves versatility.

In the above embodiment, an unmolded sheet-like material is used as the cover member 15 of the outer envelope 1, but this is not limited thereto. In the present invention, the cover member 15 may be molded. For example, the cover member may be formed from a molded product with a hat-shaped cross section, with a central portion recessed upward, and the outer peripheral edge of the hat-shaped cover member may be joined and integrated with the tray-shaped tray member 10 described above so as to cover it from above, thereby forming the outer envelope.

Example 1
(1) Preparation of outer packaging laminate material L1 As shown in Table 1, a titanium foil having a thickness of 120 μm, which is an annealed foil of pure Ti (pure titanium) of grade 1 according to ASTM B265, was prepared as the metal foil for the heat transfer layer 51 of the outer packaging laminate material (outer packaging material) L1 of Example 1. This titanium foil was used as the heat transfer layer 51, and a 40 μm thick non-oriented polypropylene (CPP) film was bonded to one side (inner surface) of the titanium foil via a urethane-based adhesive (thickness 3 μm), and a 12 μm thick polyethylene terephthalate (PET) film was bonded to the other side (outer surface) of the heat transfer layer (aluminum foil) via a urethane-based adhesive (thickness 3 μm), to produce the outer packaging laminate material L1.

(2) Preparation of inner core laminate material L2 As shown in Table 1, a pure titanium foil similar to that described above was prepared as the metal foil for the heat transfer layer 61 of the inner core laminate material (inner core material) L2 of Example 1. This titanium foil was used as the heat transfer layer 61, and a 40 μm thick non-oriented polypropylene (CPP) film was attached to both sides of the titanium foil via a urethane adhesive (thickness 3 μm) to prepare the inner core laminate material L2.

(3) Preparation of tray member 10 and cover member 15 In accordance with the embodiment shown in Figures 1 to 3, the sheet material obtained by cutting the outer laminate material L1 was subjected to deep drawing molding using a press mold to prepare a tray member 11 having a recess 11 of width (Wr) 90 mm x length (Lr) 140 mm x depth (Dr) 4 mm and a flange portion 12 of width (Wf) 10 mm formed around the entire periphery of the opening edge of the recess 11, as shown in Figures 6 and 7.

In this embodiment, the tray member 10 was processed into a sharp shape to obtain high dimensional accuracy. Specifically, the four corner radii (R1) of the recessed portion 11 were 2.0 mm, the die shoulder radius (R2) was 1.0 mm, the punch shoulder radius (R3) was 1.0 mm, and the clearance between the die and punch was 0.25 mm.

The outer laminate material L1 was then cut to produce a sheet-like cover member 15 with a size (110 mm x 160 mm) corresponding to the top surface of the tray member 11, with openings 16 (see Figures 1 to 3) formed to correspond to both sides of the recessed portion 11 of the tray member 11.

(4) Fabrication of Inner Fin 2 The above-mentioned inner core laminate material L2 was formed into a corrugated 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 as shown in Fig. 5 by a gear embossing machine, and the corrugated sheet was cut into a length of 100 mm and a width of 90 mm to fabricate the inner fin 2. The crest direction and the valley direction of the inner fin 2 are arranged along the length direction (vertical direction). Furthermore, in the inner fin 2, as in the tray member 11, the outer corner radius (R4) was set to 0.5 mm in order to give it a sharp shape.

(5) Fabrication of Header 3 As shown in Figures 2 and 3, a header 3 was fabricated by injection molding a PP resin material. The header 3 had a mounting box 31 with a height of 4 mm, a length of 90 mm, and a width of 20 mm, and a pipe 33 with an inner diameter of φ10 mm, an outer diameter of φ12 mm, and a length of 3 mm integrally formed therewith.

(6) Assembly of Heat Exchanger The heat exchanger of Example 1 was fabricated using the outer cover 1, inner fin 2, and header 3 fabricated in Example 1. That is, the headers 3, 3 were housed at both ends of the recessed portion 11 of the tray member 10 with the pipe portions 33 facing upward. Furthermore, the above-mentioned inner fin 2 was housed between the headers 3, 3 within the recessed portion 11.

Next, a cover member 15 was placed 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 16, 16 of the cover member 15 and protruded above the cover member 15.

In this way, a heat exchanger mock-up in an unjoined state was produced, and then upper and lower sealing dies that matched the shape of the mock-up were used to thermally bond (thermally fuse) the joints between the parts in the mock-up under the two sealing conditions A and B shown below, producing two types of heat exchangers of Example 1 with different sealing conditions.

Sealing condition A was performed at 190°C x 0.3 MPa x 7 seconds, with one stage of heat sealing (one stage of fusion processing) to produce a heat exchanger under sealing condition A.

Sealing condition B was 220°C x 0.4 MPa x 14 seconds, and one stage of heat sealing (one stage fusion processing) was performed to produce a heat exchanger under sealing condition B.

Example 2
The inner core laminate material L2 was prepared in the same manner as in Example 1 above, except that a 120 μm thick Fe (iron) foil of SPCC-S (standard temper) specified in JIS G3141 was used as the metal foil for the heat transfer layer 61 of the inner core laminate material L2. The inner core laminate material L2 was then processed in the same manner as in Example 1 to prepare the inner fin 2 of Example 2.

Furthermore, the heat exchanger of Example 2 was produced in the same manner as Example 1 above, except that the inner fin 2 of Example 2 was used.

Example 3
The outer laminate material L1 was prepared in the same manner as in Example 1 above, except that a 120 μm thick aluminum (Al) foil A4160-O specified in JIS H4160 was used as the metal foil for the heat transfer layer 51 of the outer laminate material L1, and the outer laminate material L1 was processed in the same manner as in Example 1 to prepare the tray member 10 and cover member 15 of Example 3.

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

<Comparative Example 1>
A heat exchanger of Comparative Example 1 was produced in the same manner as in Example 1 above, except that the same tray member and cover member 15 as in Example 3 and the same inner fins 2 as in Example 2 were used.

<Tray moldability evaluation test>
In Examples 1 to 3 and Comparative Example 1, the moldability of the tray member 10 before assembling the heat exchanger was evaluated.

That is, the tray member (molded product) 10 was inspected in a dark room by shining a light on the inside of the tray member, checking for light transmission near the corners of the tray member, and visually inspecting for pinholes and cracks. As a result, those without pinholes or cracks were rated as "○ (good)", and those with pinholes or cracks were rated as "× (bad)". The evaluation results are shown in Table 1.

As is clear from Table 1, the moldability was good for all tray members in Examples 1 to 3 and Comparative Example 1.

<Pressure resistance evaluation test>
In Examples 1 to 3 and Comparative Example 1, three heat exchangers (N=3) were prepared for each of sealing conditions A and B, and each heat exchanger was subjected to an evaluation test for pressure resistance. That is, cooling water was circulated through each heat exchanger, and the internal pressure was maintained at 1 MPa for 5 minutes, after which each heat exchanger was observed for the presence or absence of peeling (adhesion failure points) between the outer envelope 1 and the inner fin 2. As a result, those that did not have any adhesion failure points such as peeling or swelling were evaluated as "○ (good)", and those that had any adhesion failure points such as peeling or swelling were evaluated as "× (bad)". The evaluation results are shown in Table 1.

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

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

The composition of the OY water was as follows: Cl ⁻ : 200 ppm, SO ₄ ²⁻ : 60 ppm, Fe ³⁺ : 30 ppm, Cu ²⁺ : 1 ppm, and Na ⁺ : 120 ppm.

As a result of the observation, the samples that showed no corrosion were rated as "◎ (excellent)", those that showed discoloration of the metal foil due to corrosion on at least one of the outer casing 1 and the inner fin 2 were rated as "○ (good)", and those that showed leakage of liquid into the heat exchanger due to corrosion were rated as "× (bad)". The results are shown in Table 1.

As is clear from Table 1, the heat exchangers of Examples 1 to 3 have superior corrosion resistance compared to the heat exchanger of Comparative Example 1, and in particular, the heat exchanger of Example 1 has extremely superior corrosion resistance.

Regarding corrosion resistance, similar evaluation results were obtained for each example and comparative example, regardless of sealing conditions A and B.

1: Outer cover 111: Bottom wall (opposing wall)
151: Upper wall (opposing wall)
16: Inlet/outlet 2: Inner fin 25: Concave portion 26: Convex portion 51: Heat transfer layer 52: Heat fusion layer 61: Heat transfer layer 62: Heat fusion layer L1: Outer laminate material L2: Inner core laminate material

Claims (6)

A heat exchanger comprising an outer envelope having an inlet and an outlet, wherein a heat exchange medium flows in through the inlet, passes through the outer envelope, and flows out through the outlet,
The outer envelope is made of an outer envelope laminate material having a resin heat-sealing layer provided on at least the inner side of a metal heat-transfer layer,
A heat exchanger characterized in that the heat transfer layer of the outer casing is made of titanium, which has excellent corrosion resistance . The heat exchanger according to claim 1, wherein the titanium constituting the heat transfer layer of the outer casing is grade 1 according to ASTM B265. an inner fin having a concave-convex portion is disposed within the outer envelope;
The inner fin is made of an inner core laminate material having a heat fusion layer on both sides of a metal heat transfer layer,
3. The heat exchanger according to claim 1, wherein the heat transfer layer of the inner fin is made of titanium, which has excellent corrosion resistance . A heat exchanger comprising an outer envelope having an inlet and an outlet, and an inner fin disposed inside the outer envelope and having an uneven portion, wherein a heat exchange medium flowing in from the inlet passes through the outer envelope and flows out from the outlet,
The outer envelope is made of an outer envelope laminate material having a resin heat-sealing layer provided on at least the inner side of a metal heat-transfer layer,
The inner fin is made of an inner core laminate material having a heat fusion layer on both sides of a metal heat transfer layer,
4. A heat exchanger comprising: a heat transfer layer of the inner fin; and a heat transfer layer of the inner fin . The heat exchanger according to claim 3 or 4, wherein the titanium constituting the heat transfer layer of the inner fin is grade 1 according to ASTM B265. The outer envelope has a pair of opposing walls, and the inner fin is disposed between the pair of opposing walls.
6. The heat exchanger according to claim 3, wherein the bottom wall of the recess and the top wall of the protrusion of the inner fin are arranged parallel to the pair of opposing walls, and a rising wall connecting the bottom wall of the recess and the top wall of the protrusion is formed in an angular waveform perpendicular to the pair of opposing walls.

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