JP2005180806A - Heat exchanger and method for producing it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heat exchanger capable of increasing durability and reliability. <P>SOLUTION: In the heat exchanger 1 in which a low-temperature fluid layer 3 having on its surface 30a a circulation area for circulating low-temperature fluid and a high-temperature fluid layer 2 having on its surface 20a a circulation area 22 for circulating high-temperature fluid are stacked one on top of the other, the adjoining layers are joined together by diffusion joining along at least the outer peripheries 21, 31 of their stacked surfaces, and at least part of the circulation areas 22, 32 is so formed that, for example, the circulation area 32 for circulating low-temperature fluid is subjected to diffusion joining while the circulation area 22 for circulating high-temperature fluid is not joined. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a heat exchanger. In particular, the present invention relates to a heat exchanger in which a layer that circulates a high-temperature fluid and a layer that circulates a low-temperature fluid are stacked.

  As a conventional heat exchanger, the shape of the brazed fillet portion of the plate and fin is deformed as necessary to effectively prevent the occurrence of cracks and improve durability and reliability. (For example, see Patent Document 1).

Moreover, as for what used diffusion bonding without using brazing for the joining of each layer, it laminated | stacked the stainless steel plate by which the drilling process was carried out, it mutually joined, and the hole opened in the stainless steel plate or those connected It is known that a space is formed as a fluid flow path, and laminated stainless steel plates are joined to each other by solid phase diffusion bonding or liquid phase diffusion bonding (for example, see Patent Document 2).
Japanese Patent Laid-Open No. 2002-235995 JP-A-8-271175

  However, in the case of joining by brazing as in the heat exchanger described in Japanese Patent Application Laid-Open No. 2002-235995, there is a large temperature difference between the high temperature side and the low temperature side to be subjected to heat exchange under high temperature conditions, etc. In this case, there was a problem that cracks were likely to occur from the viewpoint of high-temperature strength and creep characteristics.

  Also, in the heat exchanger described in Japanese Patent Application Laid-Open No. 8-271175, a large temperature gradient and a high thermal stress are generated in association with a large temperature difference between fluids. Ensuring was a problem.

  In view of the above problems, an object of the present invention is to provide a heat exchanger with higher durability and reliability and a method for manufacturing the heat exchanger.

  The present invention relates to a heat exchanger configured by laminating a low-temperature fluid layer having a circulation region in which a low-temperature fluid circulates on a surface and a high-temperature fluid layer having a circulation region in which a high-temperature fluid circulates on a surface. Diffusion bonding is performed to adjacent layers in the outer peripheral portion of the circulation region, and at least a part of the circulation region of the low-temperature fluid layer and the high-temperature fluid layer is not bonded.

  Moreover, it is a manufacturing method of the heat exchanger of Claim 1, Comprising: Between the distribution area | region of the said high temperature fluid layer and the said low temperature fluid layer, one joining area | region joined to the layer adjacent by diffusion bonding, and another When the joining region is joined, a flow in the stacking direction is applied to the joining region by expanding the flow region as the non-joining region with hydraulic pressure or atmospheric pressure.

  Moreover, it is a manufacturing method of the heat exchanger of Claim 1, Comprising: Each layer is formed with the same kind of base material as an adjacent layer, and a different kind | species film | membrane is formed in the part used as the non-joining area | region of the surface Then, after forming the flow region by non-selective etching, the laminated layers are diffusion-bonded, and then the different material film is removed by selective etching.

  In this way, mixing and leakage of the low temperature fluid and the high temperature fluid can be suppressed by diffusion bonding the outer peripheral portion to the adjacent layers. In addition, by making at least a part of the flow region non-bonded, the overall thermal stress can be suppressed, and a heat exchanger with high durability and reliability can be configured.

  In addition, when joining the joining region, only a part of the circulation region is joined by diffusion joining by applying a load in the stacking direction to the joining region by expanding the circulation region as a non-joining region with hydraulic pressure or atmospheric pressure. A heat exchanger with high durability and reliability can be manufactured.

  In addition, each layer is formed of the same type of base material as the adjacent layer, and a different type film is formed on a portion to be a non-bonding region on the surface, and after forming the flow region by non-selective etching, Diffusion bonding between each laminated layer, and then removing the dissimilar material film by selective etching, thereby mixing the bonding region by diffusion bonding and the non-bonding region in the distribution region, and a highly reliable heat exchanger Can be manufactured.

  A first embodiment will be described. A part of the cross section of the heat exchanger 1 is shown in FIG. Here, the heat exchanger 1 will be described using, for example, a gas as a high temperature fluid and a liquid as a low temperature fluid.

  The heat exchanger 1 is configured by laminating a plurality of high-temperature fluid layers 2 that circulate a high-temperature fluid and a plurality of low-temperature fluid layers 3 that circulate a low-temperature fluid. Here, the high temperature fluid layer 2 and the low temperature fluid layer 3 are alternately laminated, but this is not restrictive. For example, one low temperature fluid layer 3 and two high temperature fluid layers 2 may be alternately stacked. Each of the high-temperature fluid layer 2 and the low-temperature fluid layer 3 is composed of plate-like substrates 20 and 30 having excellent thermal conductivity. As the base materials 20 and 30, the same kind of material is used.

  An outer peripheral portion 21 and a circulation region 22 are provided on the surface 20 a of the base material 20 constituting the high-temperature fluid layer 2. The circulation region 22 is provided with a high-temperature fluid channel 23 formed by a plurality of grooves and through which a high-temperature fluid flows, and a channel partition wall 24 formed between the high-temperature fluid channels 23. In addition, an outer peripheral portion 31 and a circulation region 32 are provided on the surface 30 a of the base material 30 constituting the low-temperature fluid layer 3. The circulation region 32 is provided with a low-temperature fluid flow path 33 through which a low-temperature fluid formed by a plurality of grooves and a flow path partition wall 34 formed between the low-temperature fluid flow paths 33 are provided. Here, the high-temperature fluid channel 23 and the low-temperature fluid channel 33 are formed by a plurality of channels, but this is not restrictive. The high temperature fluid layer 2 and the low temperature fluid layer 3 are arranged so that the surface 20a of the high temperature fluid layer 2 and the back surface 30b of the low temperature fluid layer 3 and the surface 30a of the low temperature fluid layer 3 and the back surface 20b of the high temperature fluid layer 2 are in contact with each other. The heat exchanger 1 is configured by stacking.

  Here, in a heat exchanger configured by laminating a high-temperature fluid layer and a low-temperature fluid layer, when the contact portions of the entire surface of the laminated surface are joined, the temperature difference between the high-temperature fluid layer and the low-temperature fluid layer is determined. Due to the difference in the coefficient of thermal expansion that occurs, there is a possibility that a shear stress is generated at the joint portion and a crack is generated. At this time, in particular, when a crack occurs in the outer peripheral portion, there arises a problem that the high-temperature fluid and the low-temperature fluid leak to the outside of the heat exchanger.

  Therefore, in the present embodiment, the outer peripheral portions 21 and 31 of the laminated surface are diffusion bonded to adjacent layers to prevent fluid leakage to the outside. Moreover, about the fluid area | regions 22 and 32, the thermal stress of the heat exchanger 1 whole is suppressed by making the part non-joining.

  As shown in FIG. 1, the high-temperature fluid layer 2 is diffusion-bonded with respect to the outer peripheral portion 21, and the entire circulation region 22 is not bonded. Here, it forms so that the top surface 24a of the flow path partition 24 may be located in the inner side of the base material 20 with respect to the outer peripheral part 21. FIG. That is, a gap is formed between the top surface 24 a of the flow path partition wall 24 and the back surface 30 b of the adjacent low-temperature fluid layer 3.

  On the other hand, the low temperature fluid layer 3 is joined to the adjacent high temperature fluid layer 2 with respect to the outer peripheral portion 31 and the entire circulation region 32. Here, each bonding is performed by diffusion bonding. That is, the outer peripheral portion 31 and the top surface 34 a of the flow path partition wall 34 are diffusion bonded to the adjacent high-temperature fluid layer 2. At this time, the outer peripheral portion 31 and the top surface 34a of the flow path partition wall 34 are formed in the same plane.

  Thus, in the heat exchanger 1 formed by laminating the high-temperature fluid layer 2 and the low-temperature fluid layer 3, the outer peripheral portions 21 and 31 are diffusion-bonded to prevent fluid leakage to the outside of the heat exchanger 1. be able to. For the flow regions 22 and 32, the high temperature fluid layer 2 side is non-bonded and the low temperature fluid layer 3 side is diffusion bonded. It has been experimentally confirmed by researchers that the thermal stress of the entire heat exchanger 1 is thereby suppressed. This is considered because the stress in the expansion direction in the high temperature fluid layer 2 and the stress in the reduction direction of the low temperature fluid layer 3 cancel each other by joining the high temperature fluid layer 2 and the low temperature fluid layer 3.

  Here, the entire circulation region 22 of the high-temperature fluid layer 2 is not joined, but this is not a limitation, and only a part of the circulation region 22 may be unjoined, and the other regions may be diffusion joined. . Similarly, the entire low-temperature fluid layer 3 is diffusion bonded. However, the present invention is not limited to this, and diffusion bonding may be performed only for a part of the flow region 32 and non-bonding may be performed for other regions.

  Next, the manufacturing method of such a heat exchanger 1 is demonstrated.

  In order to perform diffusion bonding between the adjacent layers 2 and 3, it is necessary to apply a large pressure in the stacking direction in a high temperature environment. At this time, it is difficult to transmit the force necessary for diffusion bonding uniformly in the stacking direction, and there is a possibility that diffusion bonding may not be performed depending on the stacked position or the position in the stacked surface. In particular, here, the flow path partition walls 34 that are diffusion-bonded and the non-bonded flow path partition walls 24 are mixed in the stacking direction, so that the high-temperature fluid layer 2 and the low-temperature fluid layer 3 are simply stacked and pressurized. Then, it is difficult to obtain a desired diffusion bonding.

  Therefore, at the time of diffusion bonding in the circulation region 32, as shown in FIG. 2, the pressure in the circulation region 22 of the high-temperature fluid layer 2 that is a non-bonding region is increased. For example, the atmospheric pressure in the distribution area 22 is increased. Alternatively, a high-pressure liquid is supplied. As a result, the gap between the top surface 24a of the high-temperature fluid channel 23 and the channel partition wall 24 and the back surface 20b of the low-temperature fluid layer 2 expands in the stacking direction, and pressure is applied to the low-temperature fluid layer 3 in the stacking direction. Here, since the high temperature fluid layer 2 and the low temperature fluid layer 3 are alternately laminated, the low temperature fluid layer 3 is pressurized from both sides in the lamination direction. In such a state, a load is further applied in the stacking direction to the stacked body formed by stacking the high temperature fluid layer 2 and the low temperature fluid side 3.

  As a result, the flow path partition wall 34 of the low temperature fluid layer 3 can be diffusion bonded to the back surface 20b of the high temperature fluid layer 2, and the flow path partition wall 24 of the high temperature fluid layer 2 can be unbonded to the back surface 30b of the low temperature fluid layer 3. . That is, it can be configured such that diffusion bonding and non-bonding overlap each other in the stacking direction. Note that the flow paths 23 and 33 may be formed by any method such as etching or machining.

  Alternatively, the heat exchanger 1 may be manufactured as shown in FIG.

  As shown in FIG. 3A, a Cu film 40 is formed by clad Cu on the surface 20a of SUS as the base material 20 of the high-temperature fluid layer 2 having a non-bonded region. The Cu film 40 is formed so as to cover the non-bonding region, here the flow region 22. Note that the combination of materials is not limited to this.

  Next, as shown in FIG. 3B, a groove corresponding to the high-temperature fluid flow path 23 is formed by etching this base material. First, an etching process is performed using an etchant that can corrode both SUS and Cu. By this processing, as shown in FIG. 3C, the top surface 24a of the flow path partition wall 24 is covered with Cu, and the base material 20 formed on the same plane as the outer peripheral portion 21 is obtained.

  As shown in FIG. 3 (d), such a base material 20 is laminated with a base material 30 which is formed with a groove corresponding to the low-temperature fluid flow path 33 by etching on one surface and is entirely made of SUS. Then, diffusion bonding is performed by applying pressure in the stacking direction in a high temperature environment. Here, since the Cu film 40 makes it easy for pressure to be transmitted in the stacking direction in the flow regions 22 and 32, the flow region 32 can be reliably diffusion-bonded. At this time, all the outer peripheral portions 21 and 31 and the flow regions 22 and 32 are diffusion bonded to adjacent layers.

  Next, the non-joining regions of the flow regions 22 and 32 are selectively etched. Here, the flow region 22 of the high-temperature fluid layer 2 is configured to be non-bonded by corroding the Cu film 40 covering the top surface 24a of the flow path partition wall 24. As a result, the heat exchanger 1 of the present embodiment as shown in FIG. 3 (e) can be manufactured.

  That is, after forming a film (Cu film 40) using a material different from the base materials 20 and 30 in the non-bonded region and diffusion bonding the entire flow regions 22 and 32, a film (Cu film) formed from a different material. 40) is selectively etched. Thereby, the formation position of a non-joining area | region and a diffusion joining area | region can be set freely.

  The shapes of the high temperature fluid layer 2 and the low temperature fluid layer 3 are not limited to this. For example, as shown in FIG. 4, the flow channel partition wall 24 may not be provided on the high temperature fluid layer 2 side, and the entire circulation region 22 may be used as the high temperature fluid flow channel 23. Also in this case, the outer peripheral parts 21 and 31 are joined by diffusion bonding. Further, the flow path partition wall 34 of the low temperature fluid layer 3 is also diffusion bonded to the adjacent layer. At this time, the circulation region 22 of the high-temperature fluid layer 2 becomes a non-joining region, and the circulation region 32 of the low-temperature fluid layer 3 becomes a diffusion joining region.

  Next, the effect of this embodiment will be described.

  In the heat exchanger 1 configured by laminating the low temperature fluid layer 3 having the circulation region 32 in which the low temperature fluid circulates on the surface 30a and the high temperature fluid layer 2 having the circulation region 22 in which the high temperature fluid circulates on the surface 20a. In addition, at least the outer peripheral portions 21 and 31 of the flow regions 22 and 32 are diffusion bonded to adjacent layers, and at least a part of the flow regions 22 and 32 of the high temperature fluid layer 2 and the low temperature fluid layer 3 is not bonded. . Thus, by making a part non-bonded, the expansion and contraction due to the heat generated in each part can be absorbed, the thermal stress generated in the entire laminate can be reduced, and the durability reliability can be improved. Moreover, the reliability with respect to the function which influences the function of the heat exchanger 1 greatly, such as mixing and leakage of a high temperature fluid and a low temperature fluid, can be ensured by making the outer peripheral parts 21 and 31 into a diffusion bonding.

  Here, a plurality of flow paths 23 and 33 for flowing fluid to the flow areas 22 and 32 and flow path partition walls 24 and 34 are provided, and at least the top surface 24a of the flow path partition wall 24 or the top surface 34a of the flow path partition wall 34 is provided. One is configured to be non-bonded to an adjacent layer in at least a part of the region. Thereby, it can avoid joining the distribution | circulation area | regions 22 and 32 whole, and generation | occurrence | production of the crack by local expansion-contraction can be suppressed.

  Moreover, let the distribution area | region 32 of the low temperature fluid layer 3 be a joining area | region joined to the adjacent layer, and let the circulation area | region 22 of the high temperature fluid layer 2 be a non-joining area | region. Thereby, the thermal stress of the whole heat exchanger 1 can be further suppressed, and durability reliability can be improved.

  Moreover, let one side be a non-joining area | region among the distribution | circulation area | regions 22 and 32 of the high temperature fluid layer 2 and the low temperature fluid layer 3, and let the other be a joining area | region joined to the adjacent layer by diffusion bonding. Here, the high temperature fluid layer 2 is defined as a non-bonding region, and the low temperature fluid layer 3 is defined as a bonding region. At the time of connecting the joining region, a load in the stacking direction is applied to the circulation region 32 which is the joining region by expanding the circulation region 22 which is a non-joining region with a hydraulic pressure or an atmospheric pressure. Accordingly, diffusion bonding in the bonding region is promoted, and bonding by diffusion bonding can be performed even when the bonding region and the non-bonding region coexist in the stacking direction.

  Alternatively, each layer is formed of the same type of base material (SUS) as the adjacent layer, and a film of a different material (Cu) (Cu film 40) is formed on a portion to be a non-bonding region on the surface, and is not selected. The distribution regions 22 and 32 are formed by etching. Here, the groove-like high-temperature fluid channel 23 and the low-temperature fluid channel 33 are formed. Thereafter, diffusion layers are bonded between the stacked layers, and then the different material (Cu) film (Cu film 40) is removed by selective etching. Thereby, a diffusion joining area | region can be formed in a part of distribution area | regions 22 and 32, and a non-joining area | region can be formed in another part. In particular, in one flow region 22 or 32, a diffusion bonding region and a non-diffusion bonding region can be mixed.

  Next, a second embodiment will be described. A part of the cross section of the heat exchanger 1 is shown in FIG.

  As in the first embodiment, the outer peripheral portions 21 and 31 are configured by diffusion bonding. Moreover, about the distribution | circulation area | regions 22 and 32, the one part is made into non-joining and the other part is joined by brazing. Here, the circulation region 22 of the high-temperature fluid layer 2 is not joined, and the circulation region 32 of the low-temperature fluid layer 3 is joined by brazing. That is, the top surface 34a of the flow path partition wall 34 and the back surface 20b of the high-temperature fluid layer 2 are joined by brazing.

  When brazing, it is not necessary to apply a large pressure in the stacking direction, and arbitrary positions can be joined. Therefore, not only the flow region 22 of the high-temperature fluid layer 2 is non-bonded and the flow region 32 of the low-temperature fluid layer 3 is bonded, but a bonded region / non-bonded region can be freely set according to the thermal stress generation distribution. Can do.

  At this time, since the bonding in the flow region 32 is performed by brazing, the strength is reduced as compared with the case of performing diffusion bonding. However, since the outer peripheral portion 31 performs diffusion bonding, the low-temperature fluid is maintained in the flow region 32 even if a crack occurs in the bonded portion by brazing due to shear stress generated by expansion and contraction of the layers 2 and 3. Therefore, it is possible to prevent the low temperature fluid from leaking and the high temperature fluid and the low temperature fluid from being mixed.

  When the outer peripheral portions 21 and 31 are diffusion bonded, the set temperature is preferably close to the brazing temperature, and it is preferable to set a longer time for the diffusion bonding.

  As described above, in this embodiment, the circulation regions 22 and 32 of the high-temperature fluid layer 2 and the low-temperature fluid layer 3 have a junction region joined to an adjacent layer by brazing and a non-joint region. When brazing is used, it is not necessary to transmit a large pressure in the stacking direction at the time of bonding, which increases the degree of freedom in layout of the bonding area and non-bonding area, and can be used freely at the desired position. Can do.

  Next, a third embodiment will be described. A part of the cross section of the heat exchanger 1 is shown in FIG. Hereinafter, a description will be given centering on differences from the first embodiment.

  As shown in FIG. 5, the outer peripheral parts 21 and 31 are joined by diffusion bonding. On the other hand, the circulation region 22 of the high-temperature fluid layer 2 and the circulation region 32 of the low-temperature fluid layer 3 are not joined together.

  That is, the top surface 24 a of the flow path partition wall 24 is configured to be located inside the base material 20 with respect to the outer peripheral portion 21. Further, the top surface 34 a of the flow path partition wall 34 is configured to be located inside the base material 30 with respect to the outer peripheral portion 31. When the low-temperature fluid layer 2 and the high-temperature fluid layer 3 are laminated, between the flow path partition wall 24 and the back surface 30b of the high-temperature fluid layer 3, and between the flow path partition wall 34 and the back surface 20b of the low-temperature fluid layer 2. The gap is formed. In such a heat exchanger 1, pressure is applied to the outer peripheral portions 21 and 31 in the stacking direction during diffusion bonding. At this time, since the diffusion bonding region is configured to overlap in the stacking direction, it is easy to transmit force in the stacking direction, and the diffusion bonding can be formed relatively easily.

Here, a liquid is used as the low temperature fluid. Therefore, when the width of the flow path partition wall 34 formed on the surface 30a of the low temperature fluid layer 3 is b ₁ and the width of the groove-like low temperature fluid flow path 33 is b ₂ , b ₁ ≧ b ₂ is satisfied. . Further, the relation between the width d ₁ of the gap between the top surface 34 a of the flow path partition wall 34 and the back surface 20 a of the high temperature fluid layer 2 and the groove depth d ₂ constituting the low temperature fluid flow path 33 is d ₁ ≦ d _2. It forms so that it becomes. That is, a thin liquid (low temperature fluid) layer is formed between the top surface 34 a of the flow path partition wall 34 and the high temperature fluid layer 2. By comprising in this way, heat exchange performance can be improved. In particular, when a low temperature liquid is circulated through the heat exchanger 1 to increase the liquid temperature or evaporate the liquid, the amount of heat obtained by the liquid can be increased by forming a thin liquid layer. .

  Next, the effect of this embodiment will be described. Here, only effects different from those of the first embodiment will be described.

  The outer peripheral portions 21 and 31 are joined by diffusion joining, and the flow regions 22 and 32 are not joined. Thereby, since the diffusion bonding region and the non-bonding region are not mixed in the stacking direction, it can be manufactured relatively easily.

Further, the flow region 32 of the low-temperature fluid layer 3 is composed of a groove-like low-temperature fluid flow path 33 and a flow path partition wall 34, and at least a part of the flow area 32 has a low temperature b ₁ and a low temperature. The relationship between the groove width b ₂ of the fluid channel 33 is b ₁ ≧ b ₂ , the relationship between the distance d ₁ between the channel partition wall 34 and the adjacent layer, and the depth d ₂ of the cryogenic fluid channel 33 is 0 <. It is configured to be a non-joining region where d ₁ ≦ d ₂ . As a result, a heat transfer area is also secured, and a thin layer is formed in a wide area in the flow region 33, so that good heat exchange performance can be obtained.

  Next, a fourth embodiment will be described. A plan view of each layer of the heat exchanger 1 is shown in FIG. FIG. 7A shows a plan view of the low-temperature fluid layer 3 and FIG. 7B shows a plan view of the high-temperature fluid layer 2. Hereinafter, a description will be given centering on differences from the first embodiment.

  Protrusions 41 are formed in the flow region 32 of the low temperature fluid layer 3. The shape of the protrusion 41 is not limited, and various shapes such as a circular cross section and a baffle plate can be used. The protrusion 41 plays a role of improving the heat exchange performance by using the flow of the low-temperature fluid in the circulation region 32 as a turbulent flow.

  Here, the protrusion 41 is provided in a partial area A of the distribution area 32 and is not provided in the other areas B. Alternatively, the region B may be provided with a protrusion having a top surface formed on the inner side of the base material 30 from the top surface 41a of the protrusion 41, that is, a protrusion having a relatively small protrusion height. The protrusion 41 provided in the region A is configured such that the top surface 41 a is formed on the same plane as the outer peripheral portion 31.

  Further, the protruding portion 42 is also formed in the circulation region 22 of the high-temperature fluid layer 2. Like the protrusion 41, the shape is not limited. However, the protrusion 42 is provided in a region A that overlaps the protrusion 41 in the stacking direction. In the other region B, no protrusion is provided. Alternatively, a protrusion having a protrusion height smaller than that of the protrusion 42 is provided. The protrusion 42 provided in the region A is configured such that the top surface 42 a is formed on the same plane as the outer peripheral portion 21.

  Such a high-temperature fluid layer 2 and a low-temperature fluid layer 3 are laminated, and the contact portion is diffusion-bonded. That is, the outer peripheral portions 21 and 31 and the protrusions 41 and 42 formed in the region A of the circulation regions 22 and 32 are diffusion-bonded to adjacent layers. At this time, since the protrusions 41 and 42 are formed so as to overlap with each other in the stacking direction, pressure can be appropriately transmitted to each layer during diffusion bonding, and diffusion bonding can be reliably generated.

  In addition, the joining area | region A in the distribution | circulation area | regions 22 and 32 is set so that not only the position shown in FIG.

  Next, the effect of this embodiment will be described. Here, only effects different from those of the first embodiment will be described.

  The protrusions 41 and 42 in some areas A are diffusion bonded to adjacent layers, and the other (area B) is not bonded. Thus, by making the partial region B of the distribution regions 22 and 32 non-joined, it is possible to suppress thermal stress and ensure durability reliability.

  In the distribution regions 22 and 32, a joining region A joined to a layer adjacent by diffusion joining and a non-joining region B are configured to overlap in the stacking direction. Thereby, the load required for diffusion bonding can be transmitted in the stacking direction, and the soundness of the bonded portion can be realized.

   In addition, the joining area | region and non-joining area | region in the distribution | circulation area | regions 22 and 32 are not necessarily limited to the shape mentioned above, What is necessary is just to provide a non-joining area | region in at least one part.

  Thus, the present invention is not limited to the best mode for carrying out the invention, and various modifications can be made within the scope of the technical idea described in the claims. Not too long.

  The present invention can be applied to a heat exchanger having a large temperature difference between a high temperature fluid and a low temperature fluid. For example, the present invention can be applied to an evaporator that is used in a fuel cell system and evaporates liquid fuel with high-temperature combustion gas.

It is sectional drawing of the heat exchanger used for 1st Embodiment. It is explanatory drawing of the manufacturing method of the heat exchanger in 1st Embodiment. It is explanatory drawing of the manufacturing method of the heat exchanger in 1st Embodiment. It is another sectional view of the heat exchanger used for a 1st embodiment. It is sectional drawing of the heat exchanger used for 2nd Embodiment. It is sectional drawing of the heat exchanger used for 3rd Embodiment. It is a top view of the fluid layer of the heat exchanger used for 4th Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Heat exchanger 2 High temperature fluid layer 3 Low temperature fluid layer 21 Outer peripheral part 22 Flow area 23 High temperature fluid flow path 24 Flow path partition (partition wall)
31 Peripheral part 32 Distribution area 33 Cryogenic fluid flow path 34 Flow path partition wall (partition wall)

Claims (7)

A cryogenic fluid layer having a flow region in which cryogenic fluid circulates on the surface;
In a heat exchanger configured by laminating a high-temperature fluid layer having a flow region in which high-temperature fluid flows on the surface,
A heat exchanger characterized in that at least a part of the flow region of the low-temperature fluid layer and the high-temperature fluid layer is non-bonded by diffusion bonding to adjacent layers at least in the outer periphery of the flow region. The flow region of the low-temperature fluid layer is a bonding region bonded to adjacent layers,
The heat exchanger according to claim 1, wherein the flow region of the high-temperature fluid layer is a non-joining region. The flow region of the low-temperature fluid layer is composed of a groove-shaped flow path and a partition wall,
And at least a part thereof is such that the relationship between the partition wall width b ₁ and the channel groove width b ₂ is b ₁ ≧ b ₂ , the distance d ₁ between the partition and the adjacent layer, and the channel _2. The heat exchanger according to claim 1, wherein the heat exchanger is configured so as to be a non-joining region in which a relationship with the depth d ₂ is 0 <d ₁ ≦ d ₂ .   The heat exchanger according to claim 1, wherein a joining region joined to an adjacent layer by diffusion joining and a non-joining region are overlapped in the stacking direction in the circulation region.   2. The heat exchanger according to claim 1, further comprising: a joining region joined to an adjacent layer by brazing or diffusion joining and a non-joining region in a circulation region of the low temperature fluid layer and the high temperature fluid layer. It is a manufacturing method of the heat exchanger of Claim 1, Comprising:
Of the flow regions of the high-temperature fluid layer and the low-temperature fluid layer, one is a bonding region bonded to an adjacent layer by diffusion bonding, the other is a non-bonding region,
A method of manufacturing a heat exchanger that applies a load in the stacking direction to the joining region by expanding a flow region, which is a non-joining region, with hydraulic pressure or atmospheric pressure when joining the joining region. It is a manufacturing method of the heat exchanger of Claim 1, Comprising:
Each layer is formed of the same type of base material as the adjacent layer, and a different type of film is formed on the surface of the non-bonded region.
A method of manufacturing a heat exchanger, which is formed by forming the flow region by non-selective etching, diffusion bonding between the stacked layers, and then removing the film of the dissimilar material by selective etching.

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