JP6793078B2 - Heat exchanger - Google Patents

Description

The present invention relates to heat exchangers. In particular, the present invention relates to a heat exchanger that transfers heat from a first fluid (high temperature side) to a second fluid (low temperature side).

In recent years, improvement in fuel efficiency of automobiles has been required. In particular, in order to prevent deterioration of fuel efficiency when the engine is cold, such as when the engine is started, cooling water, engine oil, ATF (Automatic transmission fluid), etc. are warmed at an early stage to reduce friction loss. The system to do is expected. In addition, a system for heating the catalyst for activating the exhaust gas purification catalyst at an early stage is expected.

Such a system is, for example, a heat exchanger. A heat exchanger is a device including a component (heat exchange component) that exchanges heat by circulating a first fluid inside and a second fluid outside. In such a heat exchanger, heat can be effectively utilized by exchanging heat from a high temperature fluid (for example, exhaust gas) to a low temperature fluid (for example, cooling water).

As a heat exchanger that recovers heat from a high-temperature gas such as automobile exhaust gas, a heat exchanger made of heat-resistant metal has been known, but heat-resistant metal is expensive, difficult to process, and has a high density. There were problems such as heavy weight and low heat conduction. Therefore, in recent years, the honeycomb structure is housed in the casing, the first fluid is circulated in the cell of the honeycomb structure, and the second fluid is circulated in the casing on the outer peripheral surface of the honeycomb structure. A heat exchanger has been proposed (Patent Documents 1 to 3).

9 is an example of a perspective view of the heat exchanger 30 in Patent Documents 1 to 3, and FIG. 10 schematically shows a cross-sectional view of the heat exchanger 30 cut in a cross section parallel to the axial direction. The casing 21 is formed linearly so that the honeycomb structure 1 forming the first fluid flow portion 5 from the inlet 25 of the first fluid to the outlet 26 of the first fluid is fitted, and the second fluid. The second fluid flow section 6 from the inlet 22 to the outlet 23 of the second fluid is also formed in a linear shape, and has an intersecting structure in which the first fluid flow section 5 and the second fluid flow section 6 intersect. The honeycomb structure 1 is provided so as to be fitted to the casing 21, and the seal portion 53 is formed by the outer peripheral surface of the extending outer peripheral wall 51 of the honeycomb structure 1 and the inner peripheral surface of the casing 21. The inlet 22 and the outlet 23 of the second fluid are formed on opposite sides of the honeycomb structure 1.

International Publication No. 2011/071161 Japanese Unexamined Patent Publication No. 2014-70826 International Publication No. 2012/133405

As is clear from the cross-sectional view of FIG. 10, the conventional casing has been provided as an integrally molded product (single part). It is presumed that this is because the integrally molded product has a smaller number of parts, which reduces the manufacturing cost and the burden of parts management. However, if it is premised that the casing is provided as an integrally molded product (single part), it is necessary to mold the casing mainly by plastic working such as hydroforming, pressing, and spinning, and it is necessary to mold the casing in the manufacturing process of the casing. The restrictions become large, and it is difficult to widen the structural variation of the casing.

The present invention has been made in view of such a problem, and a columnar honeycomb structure is housed in a casing, a first fluid is circulated in a cell of the columnar honeycomb structure, and a second fluid is casing. One of the issues is to increase the degree of freedom in designing the casing in the heat exchanger in which the columnar honeycomb structure is circulated on the outer peripheral side surface.

In order to solve the above-mentioned problems, the present inventor has made a diligent study and found that the casing has one or more steps on the inner side surface, and the steps are formed by joining metal pipes having different inner diameters. By doing so, it has been found that it is possible to obtain various casings that contribute to the improvement of the heat exchanger from at least one or more viewpoints such as improvement of heat recovery efficiency, improvement of structural strength, and reduction of manufacturing man-hours. The present invention has been completed based on the above findings, and is exemplified below.

[1]
A columnar honeycomb structure having a plurality of cells inside the outer peripheral side surface, which are partitioned by partition walls containing ceramics as the main component and penetrate from the first bottom surface to the second bottom surface to form a flow path for the first fluid. When,
A metal inner tube that orbits the outer peripheral side surface of the honeycomb structure,
A metal casing having a second fluid inlet and outlet, made of metal such that a second fluid flow path is formed between the outer peripheral side surface of the metal inner tube and the inner surface of the casing. A casing that orbits the outer peripheral side surface of the inner tube,
Is a heat exchanger equipped with
The casing has one or more stepped portions on the inner surface formed by joining two or more metal outer pipes having at least different inner diameters of the joint portions.
Heat exchanger.

[2]
The heat exchanger according to [1], wherein one or more of the two or more metal outer tubes have a thickness different from that of the other metal outer tubes.

[3]
The heat exchanger according to [1] or [2], wherein one or more of the two or more metal outer tubes has a wall thickness of 1.0 mm or more.

[4]
The casing includes a first metal outer tube, a second metal outer tube having an inner diameter of at least a joint portion smaller than that of the first metal outer tube joined to the first metal outer tube, and a first one. It is provided with a third metal outer tube having at least an inner diameter of the joint portion smaller than that of the first metal outer tube joined to the metal outer tube.
By joining the first metal outer pipe and the second metal outer pipe to form a step portion, and by joining the first metal outer pipe and the third metal outer pipe. Each of the formed step portions constitutes a step portion on the inner side surface of the casing.
The inner surface of the first metal outer pipe forms a second fluid flow path between the inner side surface of the casing and the outer peripheral side surface of the metal inner pipe.
The second and third metal outer tubes are joined to the metal inner tubes,
The heat exchanger according to any one of [1] to [3].

[5]
The heat exchanger according to [4], wherein the second and third metal outer pipes are joined to the metal inner pipe by welding or brazing.

[6]
The heat exchanger according to any one of [1] to [5], wherein at least one of the two or more metal outer tubes has a material composition different from that of the other metal outer tubes.

[7]
The heat exchanger according to [6], wherein at least one of two or more metal outer tubes has a material composition different from that of the other metal outer tubes, and the tensile strength is different.

[8]
The heat exchanger according to [6] or [7], wherein at least one of the two or more metal outer tubes has a material composition different from that of the other metal outer tubes and has a different coefficient of thermal expansion.

[9]
The heat exchanger according to any one of [6] to [8], wherein at least one of the two or more metal outer tubes has a material composition different from that of the other metal outer tubes and has different thermal conductivity. ..

[10]
The heat exchanger according to any one of [1] to [9], which has a portion in the flow path of the second fluid in which the height of the flow path changes in order to promote turbulence of the second fluid.

[11]
The heat exchanger according to [10], wherein the portion where the flow path height changes is formed by the casing and / or the metal inner tube having a bellows shape.

[12]
The heat exchanger according to [10], wherein the portion where the flow path height changes is formed by the step portion.

[13]
The casing includes a first metal outer tube having a reduced diameter portion and an enlarged diameter portion, and a second metal outer tube having a reduced diameter portion and an enlarged diameter portion.
The stepped portion formed by joining the first and second metal outer pipes together in the enlarged diameter portion constitutes a portion where the flow path height changes.
A second fluid flow path is formed between the outer peripheral side surface of the metal inner pipe and the inner side surface of each of the enlarged diameter portions of the first and second metal outer pipes.
The second and third metal outer tubes are joined to the metal inner tubes, respectively.
The heat exchanger according to [12].

[14]
The inlet and outlet of the second fluid are offset in the direction of cell extension.
In the extending direction of the cell, there is one or more parts where the flow path height narrows between the inlet and outlet of the second fluid.
The heat exchanger according to [12], wherein at least one of the portions where the flow path height is narrowed is formed by the step portion.

[15]
The flow path height A at the portion where the flow path height is narrowed, the flow path height B at the portion adjacent to the upstream side of the second fluid at the portion where the flow path height is narrowed, and the flow path height are The second fluid in the narrowing portion, according to [14], wherein the flow path height C in the portion adjacent to the downstream side satisfies A <B × 1/2 and / or A <C × 1/2. Heat exchanger.

[16]
The heat exchanger according to any one of [1] to [15], wherein a turbulence promoting member for promoting turbulence of the second fluid is arranged in the flow path of the second fluid. ..

The casing used in the heat exchanger according to the present invention has a high degree of freedom in design. Therefore, it is possible to provide a heat exchanger equipped with a wide variety of casings that contribute to the improvement of the heat exchanger from the viewpoints of improving heat recovery efficiency, improving structural strength, and / or reducing manufacturing man-hours. .. Therefore, the heat exchanger according to the present invention can be suitably used when recovering heat from a high-temperature gas such as automobile exhaust gas.

It is a figure for demonstrating the structure of the cross section parallel to the axial direction (the direction which a cell extends) of a columnar honeycomb structure about the heat exchanger which concerns on 1st Embodiment of this invention. The figure (AA'line cross section of FIG. 1) for explaining the structure of the heat exchanger according to the first embodiment of the present invention in the cross section perpendicular to the axial direction (the direction in which the cell extends) of the columnar honeycomb structure. Figure). It is a perspective view of the core component used in the heat exchanger which concerns on 1st Embodiment of this invention. It is a figure for demonstrating the structure of the cross section of the heat exchanger according to the 2nd Embodiment of this invention, which passes through the central axis of a columnar honeycomb structure and is parallel to the axial direction (the direction in which a cell extends). It is a figure for demonstrating the structure of the cross section of the heat exchanger according to the 3rd Embodiment of this invention, which passes through the central axis of the columnar honeycomb structure and is parallel to the axial direction (the direction in which a cell extends). It is a figure for demonstrating the structure of the cross section of the heat exchanger according to the 4th Embodiment of this invention, which passes through the central axis of a columnar honeycomb structure and is parallel to the axial direction (the direction in which a cell extends). It is a figure for demonstrating the structure of the cross section of the heat exchanger according to the 5th Embodiment of this invention, which passes through the central axis of the columnar honeycomb structure and is parallel to the axial direction (the direction in which a cell extends). It is a figure for demonstrating the structure of the cross section of the heat exchanger according to the 6th Embodiment of this invention, which passes through the central axis of a columnar honeycomb structure and is parallel to the axial direction (the direction in which a cell extends). It is an example of the perspective view of the heat exchanger disclosed in Patent Documents 1 to 3. It is sectional drawing which cut through the heat exchanger of FIG. 9 in the cross section parallel to the axial direction through the central axis.

Hereinafter, embodiments of the present invention will be specifically described with reference to the drawings. The present invention is not limited to the following embodiments, and the following embodiments are appropriately modified or improved based on the ordinary knowledge of those skilled in the art without departing from the spirit of the present invention. It should be understood that those skilled in the art also fall within the scope of the present invention.

<1 Heat exchanger>
FIG. 1 shows a structure having a cross section parallel to the axial direction (direction in which the cell extends) of the columnar honeycomb structure for the heat exchanger 100 according to the first embodiment of the present invention. FIG. 2 is a cross-sectional view taken along the line AA of FIG. 1, which is a cross section perpendicular to the axial direction (direction in which the cell extends) of the columnar honeycomb structure with respect to the heat exchanger 100 according to the first embodiment of the present invention. The structure of is shown.

The heat exchanger 100 is partitioned by partition walls containing ceramics as a main component, and has a plurality of cells on the outer peripheral side surface thereof, which penetrate from the first bottom surface 114 to the second bottom surface 116 to form a flow path for the first fluid. The columnar honeycomb structure 101 on the inside and
A metal inner tube 102 that orbitally covers the outer peripheral side surface of the honeycomb structure 101,
A casing 105 having a second fluid inlet 106 and an outlet 107 such that a second fluid flow path is formed between the outer peripheral side surface of the metal inner tube 102 and the inner side surface of the casing 105. A casing 105 that orbits the outer peripheral side surface of the metal inner tube 102,
To be equipped.
The casing 105 has one or more stepped portions 108 (108b, 108c) formed by joining the ends of two or more metal outer pipes having at least different inner diameters of the jointed portions on the inner surface surface. Have in. Further, the outer peripheral side surfaces at both ends of the metal inner tube 102 in the axial direction (direction in which the cell extends) are circularly fitted with the inner side surface of the casing 105. The step portion 108 passes through the central axis of the columnar honeycomb structure 101, and in a cross section parallel to the axial direction (direction in which the cell extends), a step perpendicular to the axial direction can be provided.

(1-1 core parts)
FIG. 3 illustrates a perspective view of the core component 120 of the heat exchanger 100 according to the first embodiment of the present invention, which is manufactured by fitting the honeycomb structure 101 and the metal inner tube 102. ..

(1-1-1 Honeycomb structure)
With reference to FIGS. 1 to 3, the honeycomb structure 101 is partitioned by partition walls containing ceramics as a main component, and penetrates from the first bottom surface 114 to the second bottom surface 116 to pass through the first fluid flow path. It has a plurality of cells to be formed. With such a configuration, the heat of the first fluid flowing through the cells of the honeycomb structure 101 can be efficiently collected and transferred to the outside. The first fluid can flow in the left-right direction of the paper surface in FIG. The first fluid is not particularly limited, and various liquids and gases can be used. For example, when the heat exchanger is used as a part of the heat exchanger mounted on the automobile, the first fluid Is preferably exhaust gas.

The shape of the honeycomb structure 101 is columnar, and there is no particular limitation as long as the first fluid can flow in the cell from the first bottom surface 114 to the second bottom surface 116. For example, it may be a cylinder, an elliptical pillar, a square pillar, or other polygonal pillar. Therefore, the outer shape of the honeycomb structure 101 in the cross section orthogonal to the axial direction (direction in which the cell extends) of the honeycomb structure 101 can be circular, elliptical, quadrangular, or other polygonal. In the first embodiment, the honeycomb structure 101 is cylindrical and its cross-sectional shape is circular.

Further, the cell shape in the cross section orthogonal to the axial direction (the direction in which the cell extends) of the honeycomb structure 101 is not particularly limited. A desired shape may be appropriately selected from a circle, an ellipse, a triangle, a quadrangle, a hexagon, or another polygon. In the first embodiment, the cross-sectional shape of the cell is quadrangular.

The partition wall of the honeycomb structure 101 is mainly composed of ceramics. "Containing ceramics as a main component" means that the mass ratio of ceramics to the total mass of the partition wall is 50% by mass or more.

The porosity of the partition wall is preferably 10% or less, more preferably 5% or less, and particularly preferably 3% or less. The porosity of the partition wall can also be 0%. The thermal conductivity can be improved by setting the porosity of the partition wall to 10% or less.

The partition wall preferably contains SiC (silicon carbide) having high thermal conductivity as a main component. "Containing SiC (silicon carbide) as a main component" means that the mass ratio of SiC (silicon carbide) to the total mass of the partition wall is 50% by mass or more.

More specifically, as the material of the honeycomb structure 101, Si-impregnated SiC, may be employed (Si + Al) impregnated SiC, metal composite SiC, recrystallized SiC, Si ₃ N _4, and SiC. Among them, it is preferable to use Si-impregnated SiC or (Si + Al) -impregnated SiC because it can be manufactured at low cost and has high thermal conductivity.

There is no particular limitation on the cell density (that is, the number of cells per unit area) in the cross section orthogonal to the axial direction (the direction in which the cells extend) of the honeycomb structure 101. The cell density may be appropriately designed, but is preferably in the range of 4 to 320 cells / cm ² . By setting the cell density to 4 cells / cm ² or more, the strength of the partition wall, the strength of the honeycomb structure 101 itself, and the effective GSA (geometric surface area) can be made sufficient. Further, by setting the cell density to 320 cells / cm ² or less, it is possible to prevent a large pressure loss when the first fluid flows.

The isostatic strength of the honeycomb structure 101 is preferably 1 MPa or more, more preferably 5 MPa or more. When the isostatic strength of the honeycomb structure 101 is 1 MPa or more, the durability of the honeycomb structure 101 can be made sufficient. The isostatic strength of the honeycomb structure 101 can be measured according to the method for measuring the isostatic fracture strength specified in the JASO standard M505-87, which is an automobile standard issued by the Society of Automotive Engineers of Japan.

The diameter of the honeycomb structure 101 in the cross section orthogonal to the extending direction of the cell is preferably 20 to 200 mm, preferably 30 to 100 mm. With such a diameter, the heat recovery efficiency can be improved. When the shape of the honeycomb structure 101 in the cross section orthogonal to the extending direction of the cell is not circular, the diameter of the maximum inscribed circle inscribed in the shape of the cross section of the honeycomb structure 101 is set in the cross section orthogonal to the extending direction of the cell. It is the diameter of the honeycomb structure 101.

The thickness of the partition wall of the cell of the honeycomb structure 101 may be appropriately designed according to the purpose, and is not particularly limited. The thickness of the partition wall is preferably 0.1 to 1 mm, more preferably 0.2 to 0.6 mm. By setting the thickness of the partition wall to 0.1 mm or more, the mechanical strength can be made sufficient and damage due to impact or thermal stress can be prevented. Further, when the thickness of the partition wall is 1 mm or less, the pressure loss of the first fluid increases due to the decrease in the opening area, and the heat recovery efficiency decreases due to the decrease in the contact area with the heat medium. Can be prevented.

The partition wall density is preferably 0.5 to ⁵ g / cm ³ . By setting the density of the partition wall to 0.5 g / cm ³ or more, the partition wall can be made sufficiently strong and can be prevented from being damaged by impact or thermal stress. Further, by setting the density of the partition wall to 5 g / cm ³ or less, the weight of the honeycomb structure 101 can be reduced. By setting the density in the above range, the honeycomb structure can be made strong, and the effect of improving the thermal conductivity can also be obtained. The partition wall density is a value measured by the Archimedes method.

The thermal conductivity of the honeycomb structure 101 is preferably 50 W / (m · K) or more, more preferably 100 to 300 W / (m · K), and 120 to 300 W / (m) at 25 ° C. -K) is particularly preferable. By setting the thermal conductivity of the honeycomb structure 101 in such a range, the thermal conductivity becomes good, and the heat inside the honeycomb structure can be efficiently transferred to the metal inner tube 102. The value of thermal conductivity is a value measured by a laser flash method (JIS R1611-1997).

When exhaust gas is flowed through the cell of the honeycomb structure 101 as the first fluid, it is preferable to support the catalyst on the partition wall of the honeycomb structure. When a catalyst is supported on the partition wall, CO, NOx, HC, etc. in the exhaust gas can be made into harmless substances by the catalytic reaction, and in addition, the heat of reaction generated during the catalytic reaction is used for heat exchange. Will be possible. As catalysts, precious metals (platinum, rhodium, palladium, ruthenium, indium, silver, and gold), aluminum, nickel, zirconium, titanium, samarium, cobalt, manganese, zinc, copper, tin, iron, niobium, magnesium, lantern, It preferably contains at least one element selected from the group consisting of samarium, bismuth, and barium. The above elements may be contained as elemental metals, metal oxides, and other metal compounds.

The amount of the catalyst (catalyst metal + carrier) supported is preferably 10 to 400 g / L. Further, in the case of a catalyst containing a noble metal, the supported amount is preferably 0.1 to 5 g / L. When the amount of the catalyst (catalyst metal + carrier) supported is 10 g / L or more, the catalytic action is likely to occur. On the other hand, when it is 400 g / L or less, the pressure loss can be suppressed and the increase in the manufacturing cost can be suppressed. The carrier is a carrier on which the catalyst metal is supported. As the carrier, it is preferable that the carrier contains at least one selected from the group consisting of alumina, ceria, and zirconia.

(1-1-2 metal inner tube)
The metal inner tube 102 is fitted to the outer peripheral side surface of the honeycomb structure 101 to orbitally cover the outer peripheral side surface of the honeycomb structure 101. As used herein, "fitting" in this context means that the honeycomb structure 101 and the metal inner tube 102 are fixed to each other in a fitted state. Therefore, in the fitting of the honeycomb structure 101 and the metal inner pipe 102, in addition to the fixing method by fitting such as crevice fitting, tight fitting, shrink fitting, brazing, welding, diffusion joining, etc., the honeycomb structure is used. The case where the body 101 and the metal inner tube 102 are fixed to each other is also included.

The metal inner tube 102 can have an inner surface shape corresponding to the outer peripheral side surface of the honeycomb structure 101. By directing the inner peripheral side surface of the metal inner tube 102 to the outer peripheral side surface of the honeycomb structure 101, the thermal conductivity is improved, and the heat inside the honeycomb structure 101 is efficiently transferred to the metal inner tube 102. Can be done.

From the viewpoint of increasing the heat recovery efficiency, it is preferable that the ratio of the area of the outer peripheral side surface portion of the honeycomb structure 101 to be circumferentially covered by the metal inner pipe 102 to the total area of the outer peripheral side surface of the honeycomb structure 101 is high. Specifically, the area ratio is preferably 80% or more, more preferably 90% or more, and 100% (that is, the entire outer peripheral side surface of the honeycomb structure 101 is orbitally covered with the metal inner pipe 102. It is even more preferable. The "side surface" here refers to a surface parallel to the axial direction of the honeycomb structure (direction in which the cell extends), and a surface orthogonal to the axial direction of the honeycomb structure (direction in which the cell extends) (first). The bottom surface 114 and the second bottom surface 116) are not included.

Since the metal inner tube 102 is made of metal, it is excellent in manufacturability. Further, the fact that the metal inner tube 102 is made of metal is also excellent in that it can be easily welded to the metal casing 105 described later. As the material of the metal inner tube 102, for example, stainless steel, titanium alloy, copper alloy, aluminum alloy, brass and the like can be used, and stainless steel is preferable because of its high durability and reliability and low cost.

The wall thickness of the metal inner tube 102 is preferably 0.1 mm or more, more preferably 0.3 mm or more, and even more preferably 0.5 mm or more for the reason of durability and reliability. The wall thickness of the metal inner tube 102 is preferably 10 mm or less, more preferably 5 mm or less, and even more preferably 3 mm or less because it reduces thermal resistance and enhances thermal conductivity.

(1-1-3 Casing)
The heat exchanger 100 according to the first embodiment of the present invention is a metal casing 105 having a second fluid inlet 106 and an outlet 107 in addition to the core component 120, and is a metal inner pipe 102. A casing 105 is provided that orbitally covers the outer peripheral side surface of the metal inner pipe so that a second fluid flow path is formed between the outer peripheral side surface and the inner side surface of the casing 105. It is preferable that the casing 105 orbitally covers the entire core component.

The casing 105 has at least one or two or more stepped portions 108 formed by joining the ends of metal outer pipes having different inner diameters of the jointed portions on the inner side surface. Forming the stepped portion 108 by joining the ends of metal outer pipes having different pipe diameters at the ends means that the casing 105 is composed of two or more members, and the casing is integrally molded. Since it is not provided as a product (single part), the degree of freedom in casing design is greatly expanded. For example, it is possible to manufacture casings having various structures that contribute to the improvement of heat exchangers from at least one or more viewpoints such as improvement of heat recovery efficiency, improvement of structural strength, and reduction of manufacturing man-hours.

The method of joining the ends of the metal outer pipes is not limited, but examples thereof include a fixing method by fitting such as clearance fitting, tightening fitting, and shrink fitting. Other fixing methods by fitting include mechanical fastening (screw connection using male and female threads, etc.), brazing, welding, diffusion joining, and the like. Instead of fitting, brazing, welding, diffusion joining, flange connection, etc. may be performed in a state where the ends of the metal outer pipes are butted against each other. Of these, mating welding is preferable in terms of work efficiency and joint strength.

In the heat exchanger 100, the casing 105 is the first metal outer tube 105a in which the end is fitted and welded to one end of the first metal outer tube 105a and the first metal outer tube 105a. A second metal outer tube 105b whose end is smaller than the end of the first metal outer tube 105b and a first metal outer tube whose end is fitted and welded to the other end of the first metal outer tube 105a. A third metal outer tube 105c having a tube diameter smaller than that of the end of 105a is provided. Further, the casing 105 is made of a second fluid inlet 106, an inlet conduit 122 connecting the inlet 106 and the first metal outer pipe 105a, a second fluid outlet 107, and an outlet 107 and the first metal. An outlet conduit 123 for connecting the outer pipe 105a is provided.

In the heat exchanger 100, the casing 105 is made of a step portion 108b formed by fitting and welding a first metal outer pipe 105a and a second metal outer pipe 105b, and a first metal. The stepped portion 108c formed by fitting and welding the outer pipe 105a and the third metal outer pipe 105c each constitutes the stepped portion 108 on the inner side surface of the casing 105. In FIG. 1, a portion (fitting welded portion) where the first metal outer pipe 105a and the second metal outer pipe 105b are fitted and welded is indicated by 103b, and the first metal outer pipe 105a and the third are shown. The portion (fitting welded portion) where the metal outer pipe 105c of the above is fitted and welded is indicated by 103c. The step portion 108b has a step corresponding to the wall thickness of the second metal outer pipe 105b, and the step portion 108c has a step corresponding to the wall thickness of the third metal outer pipe 105c. The flow path of the second fluid has a flow path height corresponding to these steps.

In the present specification, the "flow path height" of the second fluid passes through the central axis of the columnar honeycomb structure 101 and has a cross section parallel to the axial direction (direction in which the cell extends), and the outer circumference of the metal inner tube 102. Refers to the distance perpendicular to the axial direction between the side surface and the inner peripheral side surface of the casing 105.

The fitting welded portions 103b and 103c are formed continuously in a circumferential direction along the inner side surface in a direction perpendicular to the axial direction of the first metal outer pipe 105a, respectively, and the first metal outer pipe 105a and the first metal outer pipe 105a are formed. The second fluid from the casing 105 can be prevented from forming a gap between the second metal outer pipe 105b and between the first metal outer pipe 105a and the third metal outer pipe 105c. It is desirable from the viewpoint of preventing leakage. By forming the welded portion in a circular shape, the structural strength of the casing can be improved.

Such a structure of the casing 105 can also be manufactured by plastic working a straight pipe, but in that case, there is a problem that wall thinning is likely to occur in the stepped portion 108 and the structural strength is lowered. The degree of freedom in design is reduced due to the problem that plastic working is difficult when the wall thickness is thick, and the problem of springback peculiar to plastic working. In addition, when a straight pipe is manufactured by plastic working, it may be necessary to manufacture an expensive mold with a complicated shape, or an expensive processing machine may be required for plastic working. The cost is high and the production lead time tends to be long. On the other hand, when the step portion 108 is formed by joining such as fitting welding, such a problem does not occur.

In the heat exchanger 100, a second fluid flow path 110 is formed between the inner side surface of the first metal outer pipe 105a and the outer peripheral side surface of the metal inner pipe 102. The second fluid flows from the inlet 106 through the inlet conduit 122 into the casing 105. The second fluid is then heat exchanged with the first fluid flowing through the cells of the honeycomb structure 101 through the outer peripheral side surfaces of the metal inner tube 102 while passing through the flow path 110, and then through the outlet conduit 123. It flows out from the exit 107. The outer peripheral side surface of the metal inner tube 102 may be covered with a member for adjusting the heat transfer efficiency. The second fluid is not particularly limited, but when the heat exchanger is used as a heat exchanger mounted on an automobile, the second fluid is specified by water or antifreeze (JIS K2234: 2006). LLC) is preferable. Regarding the temperatures of the first fluid and the second fluid, it is preferable that the temperature of the first fluid> the temperature of the second fluid. The reason is that the metal inner tube 102 does not expand at a low temperature and the honeycomb structure 101 expands at a higher temperature, which makes it difficult for the two to loosen. In particular, when the fitting of the honeycomb structure 101 and the metal inner pipe 102 is shrink fitting, the risk of loosening the fitting and the honeycomb structure falling off can be minimized.

In the heat exchanger 100, the inlet conduit 122 is attached to the side opposite to the outlet conduit 123 with the metal inner pipe 102 interposed therebetween, but the attachment positions of the inlet conduit 122 and the outlet conduit 123 are not particularly limited, and heat exchange occurs. The axial direction and the outer peripheral direction can be appropriately changed in consideration of the installation location of the vessel 100, the piping position, and the heat exchange efficiency.

In the heat exchanger 100, the inner side surface of the second metal outer tube 105b and the third metal outer tube 105c (that is, the inner side surface of the casing 105) is fitted with the outer peripheral side surface of the metal inner tube 102. There is. In order to prevent the second fluid from leaking to the outside, it is preferable that the outer peripheral side surfaces at both ends of the metal inner pipe 102 in the axial direction (the direction in which the cell extends) have a structure in which the outer peripheral side surfaces are in close contact with the inner side surface of the casing 105 in a circumferential shape. .. The method of bringing the outer peripheral side surface of the metal inner pipe 102 into close contact with the inner side surface of the casing 105 is not particularly limited, and examples thereof include welding, diffusion joining, brazing, and mechanical fastening. Among these, welding is preferable because it has high durability and reliability and can improve the structural strength. When the fitting portion of the casing 105 and the metal inner pipe 102 is welded, the welding process can be performed in combination with the fitting welding for forming the step portion described above on the casing 105, so that the assembly manpower can be reduced. There is an advantage.

Further, since the casing 105 is composed of two or more parts, it is easy to weld the fitting portion between the casing 105 and the metal inner pipe 102. For example, in the first embodiment, after fitting and welding the inner side surfaces of the second metal outer pipe 105b and the third metal outer pipe 105c to the outer peripheral side surface of the metal inner pipe 102, the first metal Since the outer pipe 105a can be assembled, the work can be performed in a state where the access to the welded portion is easy and the visibility of the welded portion is high.

When the casing 105 is composed of a single component, it is necessary to insert the metal inner pipe 102 to the inside of the center of the casing 105, but at this time, the insertion resistance may increase and the work efficiency may decrease. However, in the first embodiment, it is sufficient to slightly insert both ends of the metal inner pipe 102 into the ends of the second metal outer pipe 105b and the third metal outer pipe 105c, so that workability is sufficient. Is high. In addition, when the casing 105 is composed of a single part, residual stress during plastic working such as hydroforming and press working affects and springs back (in the case of contracted pipe, it deforms after machining in the direction of expanding the pipe). ) Therefore, the shape accuracy deteriorates (as a result, the fitting size deteriorates and the structural strength of the welded portion decreases). Further, when plastic working of expansion / contraction such as hydroforming or press working is performed, the expansion / contraction taper portion is thinned, and the corrosion resistance is deteriorated at that portion. However, in the first embodiment, since it is composed of the members that are not subjected to the plastic working, the above concern does not occur.

Since the casing 105 is made of metal, it has excellent thermal conductivity and is also excellent in manufacturability. As the metal, for example, stainless steel, titanium alloy, copper alloy, aluminum alloy, brass and the like can be used, and stainless steel is preferable because it is inexpensive and has high durability and reliability.

The wall thickness of the casing 105 is preferably 0.1 mm or more, more preferably 0.5 mm or more, and even more preferably 1 mm or more for the reason of durability and reliability. The wall thickness of the casing 105 is preferably 10 mm or less, more preferably 5 mm or less, still more preferably 3 mm or less, from the viewpoint of cost, volume, weight and the like.

In the present invention, since it is not necessary to provide the casing 105 as an integrally molded product, the degree of freedom in designing the casing is high. The advantages of this will be described below, introducing some embodiments.

(A) Thickened straight pipe becomes difficult to plastically work as the wall thickness becomes thicker. However, in the present invention, since the casing 105 can be composed of two or more metal outer pipes, the casing 105 The wall thickness can be increased without worrying about plastic workability. For example, the wall thickness of the first metal outer tube 105a, the second metal outer tube 105b, and the third metal outer tube 105c can be 1.0 mm or more, and further 2.0 mm or more, respectively. is there. In addition, it is also possible to partially increase the wall thickness, such as increasing the wall thickness only for the first metal outer tube 105a. As a result, it is possible to increase the thickness of only the portion where corrosion is a concern and improve the corrosion resistance while minimizing the weight increase. Further, by thickening the casing 105, it is possible to improve the structural strength. Further, by increasing the thickness of the casing 105, advantages such as improvement in shape accuracy and improvement in corrosion resistance can be obtained.

(B) Use of dissimilar materials Further, in the present invention, since the casing 105 is composed of two or more metal outer tubes, at least one of them has a material composition different from that of other metal outer tubes. It can be configured to have. Thereby, for example, at least one of two or more metal outer tubes is selected from tensile strength, linear expansion coefficient, thermal conductivity, corrosion resistance, specific gravity, and specific heat different from those of other metal outer tubes. It is possible to have two characteristics.

To make the tensile strength of at least one metal outer tube different from that of other metal outer tubes, for example, use a metal outer tube having a higher tensile strength than other metal outer tubes. This is advantageous in that one or more metal outer tubes can be made thinner and lighter. On the contrary, by using a metal outer pipe whose tensile strength is lower than that of other metal outer pipes, the height of the flow path such as the bellows structure described later is changed for the metal outer pipe. The advantage is that it becomes easier to perform plastic working. Tensile strength refers to the value measured according to JIS Z2241: 2011.

Making the coefficient of linear expansion of at least one metal outer tube different from that of other metal outer tubes suppresses distortion between the other metal outer tube and peripheral members such as the metal inner tube. It is effective for. The coefficient of linear expansion refers to the coefficient of linear expansion when changed from 0 ° C. to 1000 ° C. measured according to JIS Z2285: 2003.

Making the thermal conductivity of at least one metal outer tube different from that of other metal outer tubes increases the transient response of the heat recovery efficiency of some metal outer tubes, or in a high temperature environment. It is effective when you want to reduce the thermal shock when exposed to. Thermal conductivity refers to the value measured by the laser flash method (JIS R1611-1997) at 25 ° C. The transient responsiveness of the heat recovery efficiency refers to the speed of the responsiveness of the heat recovery efficiency with respect to the passage of time, and a higher value is preferable. The reason why high transient responsiveness is preferable is that, for example, in the case of a heat exchanger that recovers heat from automobile exhaust gas, if the transient responsiveness is high, exhaust heat is exhausted immediately after the engine is started (the exhaust gas temperature becomes high). This is because the recovery enables early warm-up and has the advantage of increasing the effect of improving fuel efficiency.

For example, in the first embodiment, the material composition of the first metal outer tube 105a can be made different from the material composition of the second metal outer tube 105b and the third metal outer tube 105c. .. In this case, the material composition of the first metal outer tube 105a is made of a material having higher corrosion resistance than the second metal outer tube 105b and the third metal outer tube 105c, thereby minimizing the cost increase. At the same time, there is an advantage that corrosion resistance can be improved. Further, the material composition of the first metal outer tube 105a is set to a material composition having a lower specific gravity and / or a smaller specific heat than the second metal outer tube 105b and the third metal outer tube 105c, thereby achieving heat recovery efficiency. It is possible to improve the transient response of. That is, it is possible to prevent the amount of heat from the second fluid from being taken away by the first metal outer pipe 105a and being dissipated from the metal outer pipe 105a into the outside air. In this way, by making the material composition of only the first metal outer tube 105a a material with low specific gravity and / or specific heat, the first, second, and third metal outer tubes are made of all materials so. Compared with the case of changing to a simple material, there is an advantage that the cost is increased, the deterioration of corrosion resistance and the deterioration of workability can be minimized.

(C) Adoption of different wall thickness In the present invention, since the casing 105 is composed of two or more metal outer pipes, at least one of them has a wall thickness different from that of other metal outer pipes. It is easily possible to configure. FIG. 4 shows the heat exchanger 200 according to the second embodiment of the present invention. Since the components having the same reference numerals as those appearing in the description of the heat exchanger 100 according to the first embodiment are the same as those of the heat exchanger 100 according to the first embodiment, the description thereof will be omitted. .. The same applies to the subsequent embodiments.

In the heat exchanger 200, the wall thickness of the first metal outer tube 105a is thinner than the wall thickness of the second metal outer tube 105b and the third metal outer tube 105c. By reducing the wall thickness of the first metal outer tube 105a, the heat capacity is reduced, so that the transient response of the heat recovery efficiency can be improved. That is, by suppressing the amount of heat from the first fluid being taken away by the first metal outer tube 105a and being dissipated from the metal outer tube 105a into the outside air, a larger amount of heat can be seconded. It becomes possible to transmit to the fluid of. On the contrary, the wall thickness of the first metal outer tube 105a can be made thicker than the wall thickness of the second metal outer tube 105b and the third metal outer tube 105c. If all the wall thicknesses of the first metal outer pipe 105a, the second metal outer pipe 105b, and the third metal outer pipe 105c are reduced, the structural strength of the casing 105 is weakened as a whole, but the first By partially thickening only the metal outer tube 105a, it is possible to balance the structural strength and the heat recovery efficiency.

(D) Partial change of the inner surface of the casing In the present invention, in order to promote the turbulence of the second fluid, a portion where the flow path height changes is provided in the flow path of the second fluid. May be good. The portion where the flow path height changes is, for example, on the inner side surface of the casing forming the second fluid flow path and / or on the outer peripheral side surface of the metal inner pipe forming the second fluid flow path. It can be formed by imparting one or more concave portions, one or two or more convex portions, or a combination thereof. The portion where the flow path height changes can also be formed by the bellows shape of the casing and / or the metal inner pipe. Further, the portion where the flow path height changes shall be formed by at least one or two or more of the above-mentioned steps formed by joining the ends of the metal outer pipes having different inner diameters of the joint portion. Can be done.

FIG. 5 shows the heat exchanger 300 according to the third embodiment of the invention. In the heat exchanger 300, the first metal outer tube 105a forming the second fluid flow path between the metal inner tube 102 and the outer peripheral side surface has a bellows shape, so that the second is Since turbulence of the fluid is promoted, improvement in heat recovery efficiency can be expected. As a method of forming the first metal outer tube 105a into a bellows shape, a method of using a corrugated tube as the metal outer tube can be mentioned.

Since the casing 105 is composed of two or more metal outer pipes, the inner side surface of the first metal outer pipe 105a has a portion for changing the flow path height, while the second metal outer pipe The pipe 105b and the third metal outer pipe 105c can be straight pipes. By adopting a straight pipe as the second metal outer pipe 105b and the third metal outer pipe 105c, there is an advantage that it is easy to bring them into close contact with the metal inner pipe 102. In addition, by making the second metal outer pipe 105b and the third metal outer pipe 105c straight pipes, the cost increase of the material can be minimized and the pressure loss of the first fluid is exacerbated. Nor.

In the heat exchanger 300, the position of the inlet 106 of the second fluid is deviated from the position of the outlet 107 of the second fluid in the extending direction of the cell. Therefore, the second fluid flowing into the heat exchanger 300 from the inlet 106 always passes through the flow path 110 of the second fluid in the extending direction of the cell and then flows out from the outlet 107. That is, the flow of the second fluid entering from the inlet 106 of the second fluid is turbulent near the inner surface of the first metal outer pipe 105a, and the Reynolds number tends to increase (turbulent flow). As a result, the heat transfer coefficient can be increased and the heat recovery efficiency can be improved.

(E) Turbulence using a stepped portion As described above, in the present invention, the casing 105 is formed by joining two or more metal outer pipes having at least different inner diameters of the jointed portions. It has a portion or two or more step portions 108 on the inner surface. In the first embodiment, the step portion 108 is used to secure the flow path height of the second fluid, but separately, the step portion 108 is used to change the flow path height. It is also possible to promote the turbulence of the second fluid by allowing it to flow.

FIG. 6 shows the heat exchanger 400 according to the fourth embodiment of the invention. In the heat exchanger 400, the inner side surface of the casing 105 has a portion for changing the flow path height. The portion is formed by a step portion 108 formed on the inner side surface of the casing 105 due to fitting welding, and is provided at one location in a circumferential shape. The parts for changing the height of the flow path may be provided at one place or at a plurality of places.

Further, in the heat exchanger 400, the casing 105 is made of a first metal outer tube 105d having a reduced diameter portion 105d1 and an enlarged diameter portion 105d2, and a second metal having a reduced diameter portion 105e1 and an enlarged diameter portion 105e2. It is provided with an outer tube 105e. Both the first metal outer pipe 105d and the second metal outer pipe 105e have an end portion in the enlarged diameter portion (105d2, 105e2), and a step formed by fitting and welding these end portions to each other. The portion 108 constitutes a stepped portion 108 on the inner surface of the casing 105, whereby the flow path height changes.

In the heat exchanger 400, the position of the inlet 106 of the second fluid is deviated from the position of the outlet 107 of the second fluid with the step portion 108 in the extending direction of the cell. Therefore, the second fluid that has flowed into the heat exchanger 400 from the inlet 106 always passes through the step portion 108 and then flows out from the outlet 107. That is, the flow of the second fluid entering from the inlet 106 of the second fluid is turbulent in the vicinity of the step portion 108, and the Reynolds number tends to increase (turbulent flow). As a result, the heat transfer coefficient can be increased and the heat recovery efficiency can be improved.

In FIG. 6, a portion (fitting welded portion) where the first metal outer pipe 105d and the second metal outer pipe 105e are fitted and welded is shown by 103a. A metal tube having a reduced diameter portion and an enlarged diameter portion can be manufactured by subjecting a straight tube to a tube expanding process. The tube expansion process can be performed by plastic working such as hydroforming, pressing, and spinning.

A second fluid flow path 110 is formed between the outer peripheral side surface of the metal inner pipe 102 and the inner side surface of each of the enlarged diameter portions of the first metal outer pipe 105d and the second metal outer pipe 105e. The inner side surface of each of the reduced diameter portions (105d1, 105e1) of the first and second metal outer pipes is fitted with the outer peripheral side surface of the metal inner pipe 102. This prevents the second fluid flow path 110 from leaking out of the casing 105.

FIG. 7 shows the heat exchanger 500 according to the fifth embodiment of the present invention. Also in the heat exchanger 500, the inner surface of the casing 105 is configured so that the flow path height of the second fluid changes. In the fifth embodiment, the inner surface of the casing 105 has one portion 109 in which the flow path height narrows in the extending direction of the cell in a circumferential shape. The portion 109 where the flow path height is narrowed may be provided at one location or at a plurality of locations.

In the heat exchanger 500, the inlet 106 and the outlet 107 of the second fluid are displaced in the extending direction of the cell, and a portion 109 in which the flow path height is narrowed is formed between the inlet 106 and the outlet 107 of the second fluid. Has been done. As a result, the second fluid that has flowed into the heat exchanger 500 from the inlet 106 always passes through the portion 109 where the flow path height is narrowed and then flows out from the outlet 107. That is, the flow of the second fluid entering from the inlet 106 of the second fluid is turbulent in the vicinity of the portion 109 where the flow path height is narrowed, and the Reynolds number tends to increase (turbulent flow). Further, in the portion where the flow path height is narrow, the flow velocity is increased as compared with the portion where the flow path height is large. As a result, the heat transfer coefficient can be increased and the heat recovery efficiency can be improved.

In the heat exchanger 500, the casing 105 has a first metal outer tube 105d having a first diameter reduction portion 105d1, a diameter expansion portion 105d2, and a second diameter reduction portion 105d3, and a first diameter reduction portion 105e1 and a diameter expansion portion 105e1. It includes a second metal outer tube 105e having a portion 105e2 and a second reduced diameter portion 105e3. Both the first metal outer pipe 105d and the second metal outer pipe 105e have an end portion in the first reduced diameter portion (105d1, 105e1), and these ends are formed by fitting and welding. The stepped portion 108 constitutes the stepped portion 108 on the inner side surface of the casing 105, which narrows the flow path height. That is, the stepped portion 108 formed on the inner side surface of the casing 105 due to the fitting welding constitutes a part of the portion 109 in which the flow path height is narrowed.

In FIG. 7, a portion (fitting welded portion) where the first metal outer pipe 105d and the second metal outer pipe 105e are fitted and welded is shown by 103a. A metal tube having a reduced diameter portion and an enlarged diameter portion can be manufactured by subjecting a straight tube to a tube expanding process. The tube expansion process can be performed by plastic working such as hydroforming, pressing, and spinning.

A second fluid flow path 110 is formed between the outer peripheral side surface of the metal inner pipe 102 and the inner side surfaces of the first metal outer pipe 105d and the second metal outer pipe 105e. The inner side surface of each of the second reduced diameter portions (105d3, 105e3) of the first and second metal outer pipes is fitted with the outer peripheral side surface of the metal inner pipe 102. This prevents the second fluid flow path 110 from leaking out of the casing 105.

When the flow path height of the portion 109 where the flow path height is narrowed is low, there is an advantage that the heat transfer coefficient is increased by promoting turbulence and the increase in the flow velocity, and the heat recovery efficiency can be improved. On the other hand, the higher the flow path height of the portion 109 where the flow path height is narrowed, the smaller the water flow resistance can be obtained. Therefore, in consideration of the balance of both, the flow path height A in the portion where the flow path height is narrowed and the flow path height B in the portion adjacent to the upstream side of the second fluid in the portion where the flow path height is narrowed. And the flow path height C of the portion adjacent to the downstream side of the second fluid in the portion where the flow path height is narrowed are A <B × 1/2 and / or A <C × 1/2. It is preferable to satisfy, and it is more preferable to satisfy A <B × 1/4 and / or A <C × 1/4.

(F) Addition of turbulence promoting member From the viewpoint of promoting turbulence of the second fluid, instead of improving the surface shape of the inner side surface of the casing 105 and / or the outer peripheral side surface of the metal inner pipe 102. In addition to this, it is also useful to arrange the turbulence promoting member 124 for promoting the turbulence of the second fluid in the flow path 110 of the second fluid.

FIG. 8 shows the heat exchanger 600 according to the sixth embodiment of the present invention. In the heat exchanger 600, the turbulence promoting member 124 is arranged between the outer peripheral side surface of the metal inner pipe 102 and the inner side surface of the first metal outer pipe 105a. Specific examples of the turbulence promoting member 124 include corrugated fins and corrugated pipes. The turbulence promoting member 124 may be arranged adjacent to the outer peripheral side surface of the metal inner pipe 102, or may be arranged adjacent to the inner side surface of the casing 105. The turbulence promoting member 124 may be arranged in a circumferential shape between the outer peripheral side surface of the metal inner pipe 102 and the inner side surface of the casing 105. Further, the turbulent flow promoting member 124 may be divided and arranged in parallel with the flow direction of the first fluid instead of one. By doing so, turbulence is further promoted between the place where the turbulent flow promoting member is arranged and the place where the turbulent flow promoting member is not arranged, and the heat recovery efficiency can be improved.

In the heat exchanger 600, the position of the inlet 106 of the second fluid is deviated from the position of the outlet 107 of the second fluid in the extending direction of the cell. Therefore, the second fluid flowing into the heat exchanger 600 from the inlet 106 always passes through the flow path 110 of the second fluid in the extending direction of the cell and then flows out from the outlet 107. That is, the flow of the second fluid entering from the inlet 106 of the second fluid is turbulent in the vicinity of the turbulent flow promoting member 124, and the Reynolds number tends to increase (turbulent flow). As a result, the heat transfer coefficient can be increased and the heat recovery efficiency can be improved.

<2 Manufacturing method>
Next, the method of manufacturing the heat exchanger according to the present invention will be described by taking the heat exchanger 100 according to the first embodiment as an example. However, the method for manufacturing the heat exchanger of the present invention is not limited to the manufacturing method described below.

(2-1 Fabrication of honeycomb structure)
First, the clay containing the ceramic powder is extruded into a desired shape to prepare a honeycomb molded body. As the material of the honeycomb molded body, the above-mentioned ceramics can be used. For example, in the case of producing a honeycomb molded product containing a Si-impregnated SiC composite material as a main component, a binder and water or an organic solvent are added to a predetermined amount of SiC powder, and the obtained mixture is kneaded to form a clay. A honeycomb molded product having a desired shape can be obtained. Then, the obtained honeycomb molded body is dried, and the honeycomb molded body is impregnated with metal Si and fired in an inert gas under reduced pressure or in a vacuum to obtain a honeycomb structure having a plurality of cells partitioned by partition walls. 101 can be obtained.

(2-2 Fitting of honeycomb structure and metal inner tube)
Next, the honeycomb structure 101 is inserted into the metal inner pipe 102 to orbitally cover the outer peripheral side surface of the honeycomb structure 101. By shrink-fitting in this state, the inner peripheral side surface of the metal inner tube 102 is fitted to the outer peripheral side surface of the honeycomb structure 101. As described above, the honeycomb structure 101 and the metal inner pipe 102 can be fitted by a fixing method such as crevice fitting or tightening fitting, brazing, welding, diffusion joining, etc., in addition to shrink fitting. Can be done by As a result, the core component 120 is completed.

(2-3 Casing installation)
In the case of the heat exchanger 100 according to the first embodiment, both ends of the metal inner pipe 102 of the core component 120 are joined to the ends of the second metal outer pipe 105b and the third metal outer pipe 105c. .. As described above, there are various joining methods including fitting. If necessary, the joints can be joined by welding or the like. Next, the inner surface of one end of the first metal outer tube 105a and the outer surface of the end of the second metal outer tube 105b are joined, and the inner surface of the other end of the first metal outer tube 105a is joined. Steps 108b and 108c are formed by joining the outer surfaces of the ends of the third metal outer tube 105c. As a result, the casing 105 that orbitably covers the outer peripheral side surface of the metal inner pipe 102 is formed, and the second fluid flow path 110 is formed between the outer peripheral side surface of the metal inner pipe 102 and the inner side surface of the casing 105. Ru.

(2-4 Installation of inlet and outlet conduits)
The required number of through holes for the second fluid to enter and exit is formed on the outer surface of the first metal outer pipe 105a, and the inlet conduit 122 is formed in the formed through holes for the inlet, and the through holes for the outlet are provided. The outlet conduit 123 can be joined by welding, brazing, or the like. To attach the inlet conduit 122 and the outlet conduit 123 to the outer surface of the first metal outer pipe 105a, the first metal outer pipe 105a is attached to the second metal outer pipe 105b and the third metal outer pipe. It may be carried out before or after fitting with the pipe 105c.

With the above procedure, the heat exchanger 100 according to the first embodiment in which the casing 105 is assembled to the core component 120 can be manufactured. The heat exchanger according to the other embodiment can be manufactured by the same method.

100, 200, 300, 400, 500 Heat exchanger 101 Honeycomb structure 102 Metal inner pipe 103 Fitting weld 105 Casing 106 Second fluid inlet 107 Second fluid outlet 108 Step 109 Flow path height 110 Second fluid flow path 114 First bottom surface of honeycomb structure 116 Second bottom surface of honeycomb structure 120 Core parts 122 Inlet conduit 123 Outlet conduit 124 Turbulence promoting member

Claims (15)

A columnar honeycomb structure having a plurality of cells inside the outer peripheral side surface, which are partitioned by partition walls containing ceramics as the main component and penetrate from the first bottom surface to the second bottom surface to form a flow path for the first fluid. When,
A metal inner tube that orbits the outer peripheral side surface of the honeycomb structure,
A metal casing having a second fluid inlet and outlet, made of metal such that a second fluid flow path is formed between the outer peripheral side surface of the metal inner tube and the inner surface of the casing. A casing that orbits the outer peripheral side surface of the inner tube,
Is a heat exchanger equipped with
The casing includes a first metal outer tube, a second metal outer tube having an inner diameter of at least a joint portion smaller than that of the first metal outer tube joined to the first metal outer tube, and a first one. It is provided with a third metal outer tube having at least an inner diameter of the joint portion smaller than that of the first metal outer tube joined to the metal outer tube.
By joining the first metal outer pipe and the second metal outer pipe to form a step portion, and by joining the first metal outer pipe and the third metal outer pipe. Each of the formed step portions constitutes a step portion on the inner side surface of the casing.
The inner surface of the first metal outer pipe forms a second fluid flow path between the inner side surface of the casing and the outer peripheral side surface of the metal inner pipe.
The second and third metal outer pipes are straight pipes, both of which are joined to the metal inner pipe.
Heat exchanger. The heat exchanger according to claim 1, wherein at least one of the first metal outer tube, the second metal outer tube, and the third metal outer tube has a thickness different from that of the other metal outer tube. The wall thickness of one or more of the first metal outer tube, the second metal outer tube, and the third metal outer tube is 1.0 mm or more, according to claim 1 or 2. Heat exchanger. The heat exchanger according to any one of claims 1 to 3, wherein the second and third metal outer pipes are joined to the metal inner pipe by welding or brazing. Any one of claims 1 to 4 , wherein at least one of the first metal outer tube, the second metal outer tube, and the third metal outer tube has a material composition different from that of the other metal outer tubes. The heat exchanger described in the section. Claim 5 in which at least one of the first metal outer tube, the second metal outer tube, and the third metal outer tube has a material composition different from that of the other metal outer tubes, and the tensile strength is different. The heat exchanger described in. Claim 5 in which at least one of the first metal outer tube, the second metal outer tube, and the third metal outer tube has a material composition different from that of the other metal outer tubes, and the linear expansion coefficient is different. Or the heat exchanger according to 6 . Claim 5 in which at least one of the first metal outer tube, the second metal outer tube, and the third metal outer tube has a material composition different from that of the other metal outer tubes, and the thermal conductivity is different. The heat exchanger according to any one of 7 to 7 . The heat exchanger according to any one of claims 1 to 8 , which has a portion in the flow path of the second fluid in which the height of the flow path changes in order to promote turbulence of the second fluid. The heat exchanger according to claim 9 , wherein the portion where the flow path height changes is formed by forming the first metal outer tube and / or metal inner tube in a bellows shape. A columnar honeycomb structure having a plurality of cells inside the outer peripheral side surface, which are partitioned by partition walls containing ceramics as the main component and penetrate from the first bottom surface to the second bottom surface to form a flow path for the first fluid. When,
A metal inner tube that orbits the outer peripheral side surface of the honeycomb structure,
A metal casing having a second fluid inlet and outlet, made of metal such that a second fluid flow path is formed between the outer peripheral side surface of the metal inner tube and the inner surface of the casing. A casing that orbits the outer peripheral side surface of the inner tube,
Is a heat exchanger equipped with
The casing includes a first metal outer tube having a reduced diameter portion and an enlarged diameter portion, and a second metal outer tube having a reduced diameter portion and an enlarged diameter portion.
Stepped portion formed by the first and second metallic outer tube is engaged against the constitutes a portion flow channel height is changed,
Flow path for the second fluid are formed between the outer side surface and first and second respective inner side surface of the metallic outer tube of the metal inner tube,
The first and second metal outer tubes are joined to the metal inner tubes, respectively .
Heat exchanger. The stepped portion formed by joining the first and second metal outer pipes together in the enlarged diameter portion constitutes a portion where the flow path height changes.
A second fluid flow path is formed between the outer peripheral side surface of the metal inner pipe and the inner side surface of each of the enlarged diameter portions of the first and second metal outer pipes.
The heat exchanger according to claim 11. The inlet and outlet of the second fluid are offset in the direction of cell extension.
In the extending direction of the cell, there is one or more parts where the flow path height narrows between the inlet and outlet of the second fluid.
The heat exchanger according to claim 11 , wherein at least one of the portions where the flow path height is narrowed is formed by the step portion. The flow path height A at the portion where the flow path height is narrowed, the flow path height B at the portion adjacent to the upstream side of the second fluid at the portion where the flow path height is narrowed, and the flow path height are The thirteenth aspect of claim 13 , wherein the flow path height C of the portion adjacent to the downstream side of the second fluid in the narrowing portion satisfies A <B × 1/2 and / or A <C × 1/2. Heat exchanger. The heat exchanger according to any one of claims 1 to 14 , wherein a turbulence promoting member for promoting turbulence of the second fluid is arranged in the flow path of the second fluid.

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