JP6324150B2 - Heat exchange member and ceramic structure - Google Patents

Description

  The present invention relates to a heat exchange member using a ceramic structure capable of performing heat exchange between a first fluid and a second fluid.

  In order to improve the fuel efficiency of automobiles, exhaust heat recovery technology that recovers heat effectively from high-temperature gas such as engine combustion exhaust gas and exhaust cooling that cools exhaust gas when it is recirculated to the intake side of the engine Technology is required.

  As a heat exchanger used in such a technique, a heat exchanger using a ceramic honeycomb structure as shown in Patent Document 1 is known.

  On the other hand, according to Non-Patent Document 1, unburned methane is the main pollutant in the CNG engine that is attracting attention because it can reduce harmful substances in exhaust gas, and a high temperature of 350 to 400 ° C. is required for the purification of methane. It is necessary to warm the exhaust gas and activate the catalyst. Therefore, there is a need for a technique that can quickly raise the temperature of the catalyst during a cold start. In particular, there is a need for a gas / gas heat exchanger that can use a high-temperature gas after methane combustion to warm the low-temperature gas before combustion.

  As an example of the structure of such a gas / gas heat exchanger, Patent Document 1 discloses a structure having fins on the outer peripheral surface of a honeycomb structure. However, since the heat transfer coefficient of gas is as small as 1/10 to 1/100 that of liquid, it is necessary to increase the specific surface area required for heat transfer. There was a limit and there was a big problem in performance improvement.

  Further, as a second example of the structure of the gas / gas heat exchanger, Non-Patent Document 2 and Patent Document 2 are provided with a row sealed in the end surface portion of the honeycomb structure, and the outer circumference of the plugged row is A slot structure having an opening on the surface is mentioned. However, in this structure, both the first and second fluid flow paths are likely to have a high pressure loss (hereinafter, pressure loss may be referred to as pressure loss). There was a problem that the reliability of was low. In addition, since the structure is complicated, there is a problem that the structural strength is weak and the processing is difficult.

International Publication No. 2011/071161 International Publication No. 2010/110238

Catalysis Today 188 (2012) 106-112 International journal Heat and Mass Transfer 54 (2011) 4175-4181

  An object of the present invention is to provide a heat exchange member and a ceramic structure capable of efficiently exchanging heat between a first fluid and a second fluid with low pressure loss. In particular, a heat exchange member and a ceramic structure that are suitable for heat exchange between gases are provided.

  The present inventors distribute the first fluid to the cell and / or the three-dimensional network structure portion in the central portion of the ceramic structure, and distribute the second fluid to the cell in the outer peripheral portion, thereby It was found that can be solved. According to the present invention, the following heat exchange member and ceramic structure are provided.

[1] A three-dimensional network structure part having partition walls and / or continuous air holes that partition and form cells of 2 × 2 rows or more serving as a first fluid flow part that is a flow path of the first fluid, and an intermediate wall on the outer periphery thereof A partition and / or the three-dimensional network structure section that partitions and forms a plurality of cells serving as a second fluid flow section that is a flow path of the second fluid, and an outer peripheral wall on the outer periphery thereof, An inflow portion for allowing the second fluid to flow into the second fluid circulation portion from the outside, and a discharge portion for discharging the second fluid flowing into the second fluid circulation portion to the outside are provided on the outer peripheral wall. A ceramic structure mainly composed of ceramics provided at least in one or more pairs is provided, and the inflow portion or the discharge portion of the second fluid is a part of the outer peripheral wall of the ceramic structure. And the partition and / or the three-dimensional network structure The constricted portion is formed as a constricted portion that is constricted without forming a part of the portion, and the constricted portion is not formed at an end portion in the axial direction of the ceramic structure, and is formed at a portion other than the end portion, and the end portion In the first fluid circulation part , the outer peripheral wall and the partition wall and / or the three-dimensional network structure part are formed without mixing the first fluid and the second fluid. And a heat exchange member capable of exchanging heat through a partition existing between the second fluid circulation portion.

[2] The heat exchange member according to [1], wherein a metal tube is fitted to at least a part of the outer periphery of the ceramic structure.

[3] The heat exchange member according to [2], further including an intermediate member that is sandwiched between the metal tube and the ceramic structure and is made of a material having a Young's modulus lower than that of the metal tube.

[4] The heat exchange member according to any one of [1] to [3], wherein the inflow portion or the discharge portion of the second fluid is configured by the three-dimensional network structure portion.

[ 5 ] The cross-sectional shape perpendicular to the axial direction of the entire first fluid circulation portion in the portion where the constricted portion is formed is a square or a circle, according to any one of [ 1 ] to [4]. Heat exchange member.

[ 6 ] [1] to [ 5 ] wherein at least a part of the intermediate wall which is a partition existing between the first fluid circulation part and the second fluid circulation part is thicker than other partition walls. ] The heat exchange member in any one of.

[ 7 ] Said [1]-[ 6 ] where a shielding board is arranged at both ends of said 2nd fluid circulation part of said ceramic structure so that said 1st fluid and said 2nd fluid may not be mixed. ] The heat exchange member in any one of.

[ 8 ] The [1] to [1], wherein a part of the second fluid circulation portion of the ceramic structure is sealed so that the first fluid and the second fluid are not mixed. [ 6 ] The heat exchange member according to any one of [ 6 ].

[ 9 ] The heat exchange member according to any one of [1] to [ 8 ], wherein the ceramic structure has a thermal conductivity of 100 W / (m · K) or more.

[ 10 ] The heat exchange member according to any one of [1] to [ 9 ], wherein the ceramic structure includes silicon carbide as a main component.

[ 11 ] The heat exchange member according to any one of [1] to [ 10 ], wherein the three-dimensional network structure has a thermal conductivity of 100 W / (m · K) or more.

[ 12 ] The heat exchange member according to any one of [1] to [ 11 ], wherein the three-dimensional network structure portion includes silicon carbide as a main component.

[13] A honeycomb structure having partition walls, wherein a plurality of cells penetrating from one end surface to the other end surface are partitioned by the partition walls , and further having an outer peripheral wall on an outer periphery of the partition walls . Among them, the cell in the central portion in the radial direction is divided into the cell in the central portion and the cell in the remaining outer peripheral portion, and has an intermediate wall thicker than the partition, Is a silicon carbide, and has a thermal conductivity of 100 W / (m · K) or more, and a constricted portion in which the partition wall is not formed in the outer peripheral portion of the radial wall in the radial direction is spaced apart in the axial direction by at least 2 The constricted portion is not formed at an end portion in the axial direction of the honeycomb structure, but is formed at a portion other than the end portion, and the outer peripheral wall and the partition wall are formed at the end portion. Hani A ceramic structure that is a cam structure.

[ 14 ] The ceramic structure according to [ 13], wherein the constricted portion has a cross-sectional area of the constricted portion of 0.2 to 0.8 times the cross-sectional area of the other portion. body.

[ 15 ] The ceramic structure according to [ 13 ] or [ 14], wherein the thickness of the intermediate wall is 1.2 to 15 times based on the other partition walls.

  The heat exchange member includes a ceramic structure, and the ceramic structure includes an inflow portion for allowing the second fluid to flow into the second fluid circulation portion from the outside, and a second fluid that has flowed into the second fluid circulation portion. At least one pair of discharge portions for discharging to the outside is provided on a part of the outer peripheral wall. As a result, the heat exchange member causes the first fluid to flow through the cell and / or the three-dimensional network structure portion in the central portion of the ceramic structure, and the second fluid flows to the cell and / or the three-dimensional network in the outer peripheral portion. It can be distributed to the structure part. And heat exchange can be carried out via the partition which exists between a 1st fluid circulation part and a 2nd fluid circulation part, without mixing a 1st fluid and a 2nd fluid.

It is sectional drawing cut | disconnected by the surface parallel to an axial direction of the heat exchange member of this invention. It is the schematic diagram seen from one end surface of the axial direction of the heat exchange member of this invention. It is a perspective view which shows the honeycomb structure in which the constriction part was formed. It is a perspective view which shows the heat exchange member which made the metal pipe fit to the honeycomb structure in which the constriction part was formed. It is a mimetic diagram showing an embodiment of an end face of a honeycomb structure. It is a schematic diagram which shows other embodiment of the end surface of a honeycomb structure. It is a schematic diagram which shows Embodiment 1 of a constriction part. It is a schematic diagram which shows Embodiment 2 of a constriction part. It is a schematic diagram which shows Embodiment 3 of a constriction part. It is a schematic diagram which shows Embodiment 4 of a constriction part. It is a mimetic diagram showing an embodiment of a heat exchange member which formed a plugging part in a honeycomb structure. It is a photograph which shows the fine structure of a three-dimensional network structure part. It is a mimetic diagram showing an embodiment of a ceramics structure which formed the 2nd fluid circulation part as a three-dimensional network structure part. It is a schematic diagram which shows embodiment of the ceramic structure which formed the 1st fluid distribution | circulation part as the three-dimensional network structure part. It is a schematic diagram which shows other embodiment of the ceramic structure which formed the 2nd fluid distribution | circulation part as the three-dimensional network structure part. It is a schematic diagram which shows embodiment of the ceramic structure which formed a part of 1st fluid distribution | circulation part as a three-dimensional network structure part. It is a schematic diagram which shows embodiment of the ceramic structure which formed a part of 2nd fluid circulation part as a three-dimensional network structure part. It is a schematic diagram showing an embodiment of a ceramic structure in which a first fluid circulation part and a second fluid circulation part are formed as a three-dimensional network structure part. It is a schematic diagram which shows embodiment of the ceramic structure which used the constriction part as the three-dimensional network structure part. 6 is a schematic diagram showing an embodiment of Comparative Example 1. FIG.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The present invention is not limited to the following embodiments, and changes, modifications, and improvements can be added without departing from the scope of the invention.

(First embodiment)
(Heat exchange member)
First, the heat exchange member 10 including the honeycomb structure 1 as the ceramic structure 30 will be described as a first embodiment, and the ceramic structure 30 including the three-dimensional network structure portion 11 will be described later. FIG. 1A is a cross-sectional view of the heat exchange member 10 of the present invention cut along a plane parallel to the axial direction 9, and FIG. 1B is a schematic diagram viewed from one end face 2 in the axial direction 9. 2A is a perspective view showing the honeycomb structure 1 which is the ceramic structure 30 in which the constricted portion 16 is formed, and FIG. 2B is a perspective view of the honeycomb structure 1 in which the constricted portion 16 is formed. It is a perspective view which shows the heat exchange member 10 made to fit. 1A and 1B and FIG. 2B are drawn with the direction of the discharge portion 15 being different.

  The heat exchanging member 10 includes a partition wall 4 that partitions and forms 2 × 2 or more rows of cells 3 to be the first fluid circulation part 5 that is a first fluid channel, and a second fluid channel on the outer periphery thereof. A honeycomb structure 1 having a partition wall 4 for partitioning a plurality of cells 3 to be a second fluid circulation part 6 and an outer peripheral wall 7 on the outer periphery thereof is provided. The honeycomb structure 1 includes an inflow portion 14 for allowing the second fluid to flow into the second fluid circulation portion 6 from the outside, and a discharge portion 15 for discharging the second fluid that has flowed into the second fluid circulation portion 6 to the outside. However, at least one pair or more is provided on a part of the outer peripheral wall 7. The honeycomb structure 1 is mainly composed of ceramics. The main component means that 50% by mass or more of the honeycomb structure 1 is ceramic.

  In the heat exchange member 10, it is preferable that a metal tube 12 is fitted to at least a part of the outer periphery of the honeycomb structure 1. In FIG. 1A, the length of the metal tube 12 is longer than the length of the honeycomb structure 1 in the axial direction 9, and the honeycomb structure 1 is accommodated in the metal tube 12. Since the heat exchange member 10 includes the metal tube 12, it can be easily processed according to the installation location and the installation method, and has a high degree of freedom. The heat exchange member 10 can protect the honeycomb structure 1 by the metal tube 12 and is resistant to external impact.

  The heat exchange member 10 is preferably provided with an intermediate material 13 made of a material having a Young's modulus lower than that of the metal tube 12 sandwiched between the metal tube 12 and the honeycomb structure 1. By providing the intermediate member 13, the adhesion between the metal tube 12 and the honeycomb structure 1 is improved. Thereby, the sealing property between the metal tube 12 and the honeycomb structure 1 is improved, and when the vibration is applied to the metal tube, the intermediate material absorbs the shock and the impact is hardly transmitted to the honeycomb structure.

  Further, in the embodiment shown in FIG. 1A, shielding plates 17 are arranged at both end portions 2 of the second fluid circulation portion 6 of the honeycomb structure 1 so that the first fluid and the second fluid are not mixed. .

  With the above configuration, the heat exchange member 10 does not mix the first fluid and the second fluid, and the partition wall 4 that exists between the first fluid circulation part 5 and the second fluid circulation part 6 is interposed. Heat exchange. This will be described in more detail below.

(Honeycomb structure)
2A is a perspective view showing the honeycomb structure 1 in which the constricted portion 16 is formed, FIG. 3A is a schematic view showing an embodiment of the end face 2 of the honeycomb structure 1, and FIG. 3B is an end face 2 of the honeycomb structure 1. It is a schematic diagram which shows other embodiment.

  The honeycomb structure 1 has partition walls 4, and a plurality of cells 3 penetrating from one first end surface 2 a to the other second end surface 2 b are partitioned by the partition walls 4. Among the plurality of cells 3, an intermediate wall 8 that surrounds the cell 3 in the central portion in the radial direction and is divided into a cell 3 in the central portion and a cell 3 in the remaining outer peripheral portion and is thicker than the partition wall 4. It is preferable to provide. The intermediate wall 8 refers to a partition existing between the first fluid circulation part 5 and the second fluid circulation part 6, and is referred to as the intermediate wall 8 even when the partition walls 4 other than the intermediate wall 8 have the same thickness. And

  The cells 3 at the center of the center wall 8 serving as the first fluid circulation part 5 are composed of cells 3 in 2 × 2 rows or more. The cells 3 of 2 × 2 rows or more means that the first fluid circulation part 5 has a cell structure of 2 rows or more in the vertical direction and 2 rows or more in the horizontal direction. Thereby, heat can be efficiently transferred between the first fluid and the partition 4.

  The external shape of the honeycomb structure 1 is not limited to a cylindrical shape (columnar shape), but an elliptical cross section perpendicular to the axial (longitudinal) direction 9, an oval shape in which arcs are combined, a square shape, or other polygonal shape It may be columnar. By having the partition walls 4, heat from the fluid flowing through the inside of the honeycomb structure 1 can be efficiently collected and transmitted. When the honeycomb structure 1 is cylindrical, the diameter is preferably 200 mm or less, and more preferably 100 mm or less.

  The main component of the honeycomb structure 1 is preferably composed mainly of ceramics, more preferably silicon carbide. Here, a main component means what occupies 50 mass% or more. Furthermore, the honeycomb structure 1 preferably has a thermal conductivity of 100 W / (m · K) or more. Such a honeycomb structure 1 is suitable as the heat exchange member 10 because of its good thermal conductivity. The thermal conductivity was measured for a test piece cut out from the honeycomb structure by a thermal diffusivity measured by an optical alternating current method, a specific heat measured by a DSC (Differen-tial Scanning Calorimetry) method, and Archimedes. The value at room temperature is calculated using the value of density measured by the method.

  The second fluid inflow portion 14 or discharge portion 15 formed in the honeycomb structure 1 of the heat exchange member 10 does not form part of the outer peripheral wall 7 and part of the partition walls 4 of the honeycomb structure 1. It is formed by. The inflow portion 14 and the discharge portion 15 are configured as a constricted portion 16 having a constricted shape. That is, the honeycomb structure 1 is provided with at least two constricted portions 16 in which the partition walls 4 are not formed in the outer peripheral portion of the intermediate wall 8 in the radial direction. Since the inflow portion 14 and the discharge portion 15 are formed as the constricted portion 16, the second fluid can be caused to flow into the second fluid circulation portion 6 and discharged (outflow) from the second fluid circulation portion 6. . Even if the plurality of cells 3 are formed in the second fluid circulation portion 6, the second fluid can be easily circulated.

  The cross-sectional shape perpendicular to the axial direction 9 of the entire first fluid circulation portion 5 in the portion where the constricted portion 16 is formed can be formed into a square or a circle. For example, in FIG. 2A, the cross-sectional shape perpendicular to the axial direction 9 of the entire first fluid circulation part 5 is formed as a circle, and the second fluid circulation part 6 is also formed as a circle.

  The cross-sectional shape of the constricted portion 16 is preferably a quadrilateral shape although the shape formed at the constricted portion is preferably a circle in the cross section perpendicular to the axial direction 9 of the honeycomb structure 1 (see FIG. 2A). It may be.

  As shown in FIG. 4A, the cross-sectional shape of the constricted portion 16 is a rectangle (FIG. 4B), a trapezoid (as shown in FIG. 4A, rather than a triangular shape formed in the constricted portion in a cross section parallel to the axial direction 9 of the honeycomb structure 1. It is preferable that the outer peripheral side is large) (FIG. 4C), and it is preferable that the corner portion of the constricted portion is not a pin angle (corner with a sharp tip) (FIG. 4D).

  The constricted portion 16 is preferably formed so as to be separated in the axial direction 9. Further, it is preferable that the constricted portion 16 is not formed at the end portion in the axial direction 9 of the honeycomb structure 1 but is formed at a portion other than the end portion, and the outer peripheral wall 7 and the partition wall 4 are formed at the end portion. . That is, as shown in FIG. 1A, the constricted portion 16 is not the endmost portion, but is formed closer to the center in the axial direction 9 than that. The position La (see FIG. 4B) of the constricted portion 16 is preferably 2 mm or more and 50 mm or less, more preferably 5 mm or more and 30 mm or less from the end face 2 of the honeycomb structure 1. By forming in this way, durability reliability can be improved.

  The length Lb (see FIG. 4B) of the constricted portion 16 in the axial direction 9 of the honeycomb structure 1 is preferably 3 mm to 50 mm, and more preferably 5 mm to 30 mm. Here, the length Lb of the constricted portion 16 refers to the length of the longest portion of the constricted portion 16 in the cross section parallel to the axial direction 9 of the honeycomb structure 1.

  The constricted portion 16 preferably has a cross-sectional area of the constricted portion of 0.2 to 0.8 times the cross-sectional area of the other portion.

  The maximum depth Lc (see FIG. 4B) of the constricted portion 16 is preferably 10% or more and 50% or less, and preferably 20% or more and 40% or less, with respect to the radius other than the constricted portion (end face 2 etc.) More preferably, it is a depth.

  As shown in FIG. 1A, a plurality of cells 3 serving as a first fluid circulation part 5 serving as a first fluid flow path and a second fluid circulation part 6 serving as a second fluid flow path on the outer periphery thereof. By providing the inflow part 14 and the discharge part 15 formed as the constricted part 16 in the honeycomb structure 1 having a plurality of cells 3, the pressure loss in the first fluid circulation part 5 and the second fluid circulation part 6 is reduced. Can be reduced. For example, in FIG. 12, the first fluid circulation part 5 and the second fluid circulation part 6 are alternately formed for each row. In such a slot structure, the first fluid and the second fluid Since the inlet area of the channel inlet is reduced, the pressure loss is increased. However, in the heat exchanging member 10 as shown in FIG. 1A, the first fluid circulation part 5 and the second fluid circulation part 6 are not alternately formed in each row, and the pressure loss is large because the inlet area is large. Is small.

  In the slot structure, since the interface between the first fluid and the second fluid exists every other layer, the entire partition wall 4 is made thick in order to ensure the sealing property between the fluids (prevent gas leakage). There is a need to do. On the other hand, in this structure, since the interface between the first fluid and the second fluid is limited within the honeycomb structure 1, the thickness of the partition wall 4 (intermediate wall 8) is increased in order to ensure sealing performance. do it.

  Further, in the slot structure, since the flow paths of the first fluid and the second fluid exist every other layer, the temperature difference per fixed distance within the member is large and the generated stress tends to increase. Further, since a complicated structure is formed inside the honeycomb structure 1, it is difficult to ensure the structural strength. On the other hand, in this structure, the flow paths of the first fluid and the second fluid are divided into the central portion and the outer peripheral portion of the honeycomb structure 1, respectively, so that the temperature difference per unit distance and the generated stress can be reduced ( It is also possible to increase the structural strength by increasing the thickness of the partition wall 4 at the fluid interface where the temperature difference increases. Moreover, since the structure is simple, the structural strength is increased.

  In addition, in the slot structure, after the honeycomb structure 1 is extruded, precision is required for the processing of the slot portion in order to ensure the sealing performance of the first fluid and the second fluid. Although processing is required at the entrance / exit part of the fluid circulation part 6, the processing itself (peripheral deletion) can be easily achieved.

It is preferable that at least a part of the intermediate wall 8, which is a partition wall existing between the first fluid circulation part 5 and the second fluid circulation part 6, is thicker than the other partition walls 4. In Figure 3A, the thickness t _b of the intermediate wall is thicker than the thickness t _a of the partition wall 4. More specifically, the thickness t _b of the intermediate wall 8 of the honeycomb structure 1 is preferably 1.2 to 15 times based on the other partition walls 4. By comprising in this way, pressure resistance can be improved, sealing performance can be ensured, and heat exchange can be performed without mixing the first fluid and the second fluid.

  The honeycomb structure 1 preferably has a thermal conductivity of 100 W / (m · K) or more. More preferably, it is 120-300 W / (m * K), More preferably, it is 150-300 W / (m * K). By setting it as this range, heat conductivity becomes favorable and it is possible to efficiently exchange heat between the first fluid and the second fluid.

  The honeycomb structure 1 is preferably made of ceramics having excellent heat resistance, and considering heat conductivity in particular, it is preferable that SiC (silicon carbide) having high thermal conductivity is a main component. The main component means that 50% by mass or more of the honeycomb structure 1 is silicon carbide.

  However, it is not always necessary that the entire honeycomb structure 1 is made of SiC (silicon carbide), and it is sufficient that SiC (silicon carbide) is included in the main body. That is, the honeycomb structure 1 is preferably made of ceramics containing SiC (silicon carbide).

  In addition, even if it is SiC (silicon carbide), in the case of a porous body, high thermal conductivity cannot be obtained. Therefore, it is preferable to impregnate silicon in the process of manufacturing the honeycomb structure 1 to obtain a dense structure. High heat conductivity can be obtained by using a dense structure. For example, in the case of a porous body of SiC (silicon carbide), it is about 20 W / (m · K), but can be made about 150 W / (m · K) by using a dense body.

As the honeycomb structure 1, Si-impregnated SiC, (Si + Al) -impregnated SiC, metal composite SiC, recrystallized SiC, Si ₃ N ₄ , SiC, or the like can be adopted, but a dense body for obtaining a high heat exchange rate Si-impregnated SiC or (Si + Al) -impregnated SiC can be used for the structure. Si-impregnated SiC has a structure in which the SiC particle surface is surrounded by solidified metal-silicon melt and SiC is integrally bonded via metal silicon, so that silicon carbide is shielded from an oxygen-containing atmosphere and prevented from oxidation. Is done. Furthermore, SiC has the characteristics of high thermal conductivity and easy heat dissipation, but SiC impregnated with Si is densely formed while exhibiting high thermal conductivity and heat resistance, and has sufficient strength as a heat transfer member. Indicates. That is, the honeycomb structure 1 made of a Si—SiC-based (Si impregnated SiC, (Si + Al) impregnated SiC) material has excellent heat resistance, thermal shock resistance, oxidation resistance, and excellent corrosion resistance against acids and alkalis. And high thermal conductivity.

  The porosity is preferably 10% or less, and preferably 3% or less. By setting it as such a range, thermal conductivity can be improved.

The density of the partition walls 4 of the cells 3 of the honeycomb structure 1 is preferably 0.5 to ⁵ g / cm ³ . In the case of 0.5 g / cm ³ or more, the strength of the partition wall 4 is sufficient, and the partition wall 4 can be prevented from being damaged by pressure when the first fluid passes through the flow path. Further, if it is 5 g / cm ³ or less, the honeycomb structure 1 itself does not become too heavy, and the weight can be reduced. By setting the density within the above range, the honeycomb structure 1 can be strengthened. Moreover, the effect which improves heat conductivity is also acquired.

  When the honeycomb structure 1 is formed as the honeycomb structure 1 in which a plurality of cells 3 serving as flow paths are partitioned by partition walls 4, the cell shape may be circular, elliptical, triangular, quadrangular, hexagonal, or other various shapes. What is necessary is just to select a desired shape from squares etc. suitably. Further, the shape of the cell 3 at the center portion from the intermediate wall 8 and the shape of the cell 3 at the outer peripheral portion from the intermediate wall 8 may be different.

  The cell density of the honeycomb structure 1 (that is, the number of cells per unit cross-sectional area) is not particularly limited, and may be appropriately designed according to the thickness of the partition walls 4 from the viewpoint of the structural strength of the honeycomb structure 1. The isostatic strength of the honeycomb structure 1 is preferably 1 MPa or more, and more preferably 5 MPa or more.

  The number of cells per honeycomb structure 1 is preferably 16 to 10,000, and particularly preferably 50 to 2,000. If the number of cells is too large, the honeycomb itself becomes large, so the heat conduction distance from the first fluid side to the second fluid side becomes long, the heat conduction loss becomes large, and the heat flux becomes small. In addition, when the number of cells is small, the heat transfer area on the first fluid side becomes small, the heat resistance on the first fluid side cannot be lowered, and the heat flux becomes small.

  The thickness (wall thickness) of the partition walls 4 (excluding the intermediate wall 8) of the cells 3 of the honeycomb structure 1 may be appropriately designed according to the purpose, and is not particularly limited. The wall thickness is preferably 0.1 to 1 mm, and more preferably 0.2 to 0.5 mm. When the wall thickness is 0.1 mm or more, the mechanical strength is improved and damage due to impact or thermal stress can be prevented. On the other hand, when the thickness is 1 mm or less, the ratio of the cell volume to the honeycomb structure 1 side increases, so that the pressure loss of the fluid decreases and the heat exchange rate can be improved.

  When the first fluid (high temperature side) is exhaust gas, it is preferable that a catalyst is supported on the wall surface inside the cell 3 of the honeycomb structure 1 through which the first fluid passes. This is because in addition to the role of exhaust gas purification, reaction heat (exothermic reaction) generated during exhaust gas purification can also be exchanged. Precious metals (platinum, rhodium, palladium, ruthenium, indium, silver and gold), aluminum, nickel, zirconium, titanium, cerium, cobalt, manganese, zinc, copper, tin, iron, niobium, magnesium, lanthanum, samarium, bismuth and It is preferable to contain at least one element selected from the group consisting of barium. These may be metals, oxides, and other compounds.

  The supported amount of catalyst (catalyst metal + supported body) supported on the partition walls 4 of the cells 3 of the first fluid circulation section 5 of the honeycomb structure 1 through which the first fluid passes is 10 to 400 g / L. If it is a noble metal, it is still more preferable that it is 0.1-5 g / L. When the amount of the catalyst (catalyst metal + support) supported is 10 g / L or more, the catalytic action is sufficiently exhibited. On the other hand, when it is 400 g / L or less, the pressure loss does not become too large, and an increase in manufacturing cost can be suppressed.

(Metal pipe)
As shown in FIG. 1A, the honeycomb structure 1 can be protected by being accommodated in the metal tube 12. Moreover, it is one of the preferable forms that the metal pipe 12 is longer than the length in the axial direction 9 of the honeycomb structure 1. If comprised in this way, it will be easy to process the edge part of the metal pipe 12 according to the installation place and application of the heat exchange member 10. FIG. However, the embodiment is not limited to the embodiment of FIG. 1A, and the metal tube 12 may be the same as or shorter than the length of the honeycomb structure 1 in the axial direction 9.

  As the metal tube 12, one having heat resistance and corrosion resistance is preferable. For example, a SUS tube, a copper tube, a brass tube, or the like can be used. The pressure between the honeycomb structure 1 and the metal tube 12 due to the difference in thermal expansion coefficient between the metal tube 12 and the honeycomb structure 1 due to the temperature of the second fluid flowing on the outer peripheral surface of the metal tube 12. It is necessary to prevent from missing. For this reason, the metal tube 12 having an inner diameter smaller than the outer diameter of the honeycomb structure 1 is preferably fitted at normal temperature.

(Intermediate material)
The heat exchange member 10 preferably includes an intermediate material 13 made of a material having a Young's modulus lower than that of the metal tube 12 sandwiched between the honeycomb structure 1 and the metal tube 12. Adhesion is improved by providing the intermediate member 13 made of a material having a Young's modulus lower than that of the metal tube 12 between the honeycomb structure 1 and the metal tube 12 on the outer peripheral side thereof. Thereby, the sealing performance between the metal pipe 12 and the honeycomb structure 1 becomes good. Examples of the intermediate material 13 include a heat insulating mat and a graphite sheet.

(Shielding part)
As shown to FIG. 1A, the shielding board 17 is arrange | positioned as a shielding part at the both ends 2 of the 2nd fluid circulation part 6 of the honeycomb structure 1 so that a 1st fluid and a 2nd fluid may not mix. It is preferable. In FIG. 1B, ring-shaped shielding plates 17 are provided on both end surfaces 2 of the honeycomb structure 1. As the shielding plate 17, for example, metal, specifically, stainless steel or the like can be used. The shielding plate 17 is provided in contact with the end surface 2 of the honeycomb structure 1 so as to block the second fluid circulation portion 6 of the honeycomb structure 1. When the honeycomb structure 1 is fitted, it can be manufactured by fitting the shielding plate 17 with both end faces 2 provided. In this way, the honeycomb structure 1 can be more firmly fixed to the metal tube 12.

  Instead of arranging the shielding plate 17, a part of the opening of the second fluid circulation part 6 of the honeycomb structure 1 may be sealed. In FIG. 5, plugged portions 18 are formed at both ends of the cell 3 of the second fluid circulation portion 6. However, the shielding part is not limited to the shielding plate 17 or the sealing.

(Method for producing heat exchange member)
First, the manufacturing method of the honeycomb structure 1 will be described, and then the fitting between the metal tube 12 and the honeycomb structure 1 will be described.

  First, SiC powders having different average particle diameters are mixed to prepare a mixture of SiC powders. This SiC powder mixture is mixed with a binder and water, and kneaded using a kneader to obtain a kneaded product. This kneaded product is put into a vacuum kneader to produce a cylindrical clay.

  Next, the kneaded material is extruded to form a honeycomb formed body. In extrusion molding, the shape and thickness of the outer peripheral wall 7, the thickness of the partition walls 4, the shape of the cells 3, the cell density, etc. can be made desired by selecting an appropriate form of die and jig. . It is preferable to use a die made of a cemented carbide that hardly wears. The honeycomb molded body is formed so that the outer peripheral wall 7 has a cylindrical shape or a quadrangular prism shape, and the inside of the outer peripheral wall 7 is divided into a square lattice shape by the partition walls 4. Further, the partition walls 4 are formed so as to be parallel to each other at equal intervals in each of the directions orthogonal to each other and to cross the inside of the outer peripheral wall 7 straightly. Thereby, the cross-sectional shape of the cell 3 other than the outermost peripheral part inside the outer peripheral wall 7 can be made square.

  Next, the honeycomb formed body obtained by extrusion molding is dried. First, the honeycomb formed body is dried by an electromagnetic heating method, and then dried by an external heating method. By such two-stage drying, moisture corresponding to 97% or more of the total amount of water contained in the honeycomb formed body before drying is removed from the honeycomb formed body.

  Next, the constricted portion 16 is formed in the honeycomb structure 1. The constricted portion 16 can be formed by removing the partition walls 4 in the outer peripheral portion of the honeycomb molded body from the outer peripheral wall 7 and the intermediate wall 8.

  Next, the honeycomb formed body is degreased in a nitrogen atmosphere. Furthermore, a lump of metal Si is placed on the honeycomb structure 1 obtained by such degreasing and fired in vacuum or in an inert gas under reduced pressure. During the firing, the lump of metal Si placed on the honeycomb structure 1 is melted, and the outer peripheral wall 7 and the partition walls 4 are impregnated with metal Si. For example, when the thermal conductivity of the outer peripheral wall 7 and the partition wall 4 is set to 100 W / (m · K), a mass of 70 parts by mass of metal Si is used with respect to 100 parts by mass of the honeycomb structure. Further, when the thermal conductivity of the outer peripheral wall 7 and the partition wall 4 is set to 150 W / (m · K), 80 parts by mass of metal Si is used with respect to 100 parts by mass of the honeycomb structure.

  Next, a method for integrating the honeycomb structure 1 manufactured as described above and the metal tube 12 will be described. In addition, after providing the intermediate material 13 on the outer peripheral side of the honeycomb structure 1, it is one of preferable modes that the metal pipe 12 is fitted to the honeycomb structure 1.

  First, for example, a heat insulating mat used as the intermediate member 13 is wound around the outer peripheral surface of the outer peripheral wall 7 of the honeycomb structure 1. At this time, you may stick using an adhesive agent. Subsequently, the metal tube 12 is heated to about 1000 ° C. with a high-frequency heater. Then, the honeycomb structure 1 can be inserted into the metal tube 12 and integrated by fitting to form the heat exchange member 10.

  The shielding plate 17 may be inserted together (continuously) when the honeycomb structure 1 is fitted, or may be inserted separately. The continuous insertion is preferable because it plays a role of protecting the honeycomb structure 1 and the soft intermediate material 13.

(Second embodiment)
An embodiment in which at least a part of the ceramic structure 30 is provided with a three-dimensional network structure portion 11 having ceramic as a main component and continuous pores will be described.

The three-dimensional network structure 11 has a pore diameter of 200 μm to 5 mm, an open porosity of 70 to 99%, a density of 0.06 to 0.6 g / cm ³ , and is formed of a sponge-like porous structure having continuous air holes. ing. FIG. 6 is a photograph showing the microstructure of the three-dimensional network structure unit 11. As shown in FIG. 6, the sponge-shaped porous structure is formed by a branch portion 24 and a merge portion 23 where the branch portions 24 merge. The branch diameter of the branch portion 24 where the cross-sectional area is the smallest (if the cross-section is not a circle, (cross-sectional area / π) ^0.5 × 2) is the minimum branch diameter 25, and the minimum branch diameter of the 20 branch portions 25 is measured, the average minimum branch diameter 25 calculated from the average value is 0.1 to 2 mm, the average aperture ratio (the average of the aperture ratio (area of the opening portion / cross-sectional area) in each cross section) is 30 to 90% is preferable.

  The three-dimensional network structure 11 preferably has a thermal conductivity of 100 W / (m · K) or more. More preferably, it is 120-300 W / (m * K), More preferably, it is 150-300 W / (m * K). By setting it as this range, heat conductivity becomes favorable and it is possible to efficiently exchange heat between the first fluid and the second fluid.

  The three-dimensional network structure 11 is preferably made of ceramics having excellent heat resistance, and considering heat conductivity in particular, it is preferable that SiC (silicon carbide) having high thermal conductivity is the main component. The main component means that 50% by mass or more of the honeycomb structure 1 is silicon carbide.

  2nd embodiment is the heat exchange member 10 provided with the ceramic structure 30 which equips at least one part with the above three-dimensional network structure parts 11. FIG.

  FIG. 7 shows an embodiment of a ceramic structure 30 in which the second fluid circulation part 6 is formed as a three-dimensional network structure part 11. In the embodiment of FIG. 7, the constricted portion 16 is not formed, but the inflow portion 14 and the discharge portion 15 are formed in a part of the second fluid circulation portion 6. By forming such a first embodiment, the first fluid circulation part 5 and the second fluid circulation part 6 are formed as the three-dimensional network structure part 11, so that the contact with the fluid is increased, so that the heat exchange efficiency is improved. To do. Further, in this embodiment, since the constricted portion 16 is not formed, even in the portion of the volume occupied by the constricted portion 16 (the volume that did not substantially affect the heat exchange), it is in contact with the gas. Heat exchange efficiency can be improved within the same volume. That is, compared with the embodiment in which the constricted portion 16 is formed, the space is efficiently used and the heat exchange efficiency can be improved. Furthermore, in the embodiment in which the constricted portion 16 is formed, stress is easily generated in the constricted portion 16, but in this embodiment, there are few stress concentration portions. As a result, the structural strength is improved. In FIG. 7, the metal tube 12 (and the intermediate member 13) is not drawn, but only the locations of the inflow portion 14 and the discharge portion 15 are not covered with the metal tube 12 (and the intermediate member 13) (the metal tube 12 (and An opening is formed in the intermediate material 13). Thus, the second fluid that has flowed in at the inflow portion 14 passes through the entire area of the second fluid circulation portion 6 formed in a three-dimensional network structure and is discharged from the discharge portion 15.

  FIG. 8A shows an embodiment of a ceramic structure 30 in which the first fluid circulation part 5 is formed as a three-dimensional network structure part 11. FIG. 8B shows an embodiment of a ceramic structure 30 in which the second fluid circulation part 6 is formed as a three-dimensional network structure part 11. 8A and 8B show an embodiment in which the constricted portion 16 is formed. By adopting such an embodiment, compared to the embodiment in which the constricted portion 16 is not formed, the pressure loss of the second fluid at the inflow portion 14 and the discharge portion 15 can be reduced, and the second fluid can be efficiently transferred to the first fluid. The fluid can be circulated throughout the two-fluid circulator 6.

  FIG. 9A shows a ceramic structure 30 in which a part of the first fluid circulation part 5 is formed as a three-dimensional network structure part 11. FIG. 9B shows a ceramic structure 30 in which a part of the second fluid circulation portion 6 is formed as a three-dimensional network structure portion 11. Although a figure shows embodiment provided with the three-dimensional network structure part 11 in the center part of the axial direction 9, it is not limited to this. Alternatively, the three-dimensional network structure 11 may be provided in two or more locations. By adopting such an embodiment, the flow of fluid can be disturbed in the three-dimensional network structure portion 11, heat transfer between the fluid and the ceramic structure 30 is promoted, and the fluid to the ceramic structure 30 (or the ceramic structure). Heat can be transferred efficiently (from the body 30 to the fluid).

  FIG. 10 shows an embodiment of a ceramic structure 30 in which both the first fluid circulation part 5 and the second fluid circulation part 6 are formed as a three-dimensional network structure part 11. By adopting such an embodiment, when the fluid flows into the three-dimensional network structure 11, the fluid is agitated, and the fluid temperature distribution in the cross section that tends to become steep is usually smoothed (averaged). be able to. On the other hand, for example, when the first fluid circulation part 5 is formed in a honeycomb structure, the fluid is not agitated in the first fluid circulation part 5, so that the central part of the cross section becomes high temperature and the outer peripheral part of the cross section becomes low temperature. Easily, the temperature distribution in the cross section of the first fluid becomes steep. In this embodiment, as a result of the fluid temperature distribution becoming gentle (averaged), the temperature difference between the first fluid near the intermediate wall 8 and the second fluid (or the first fluid circulation near the intermediate wall 8). The temperature difference between the part 5 and the second fluid circulation part 6 is increased, the amount of heat transfer between the fluids is increased, and the heat exchange efficiency can be improved.

  FIG. 11 shows a ceramic structure 30 in which the three-dimensional network structure portion 11 is formed in the constricted portion 16. If it does in this way, the narrow part 16 which was space can be used effectively, and heat exchange efficiency can further be improved.

  Next, the manufacturing method of the three-dimensional network structure part 11 is demonstrated. First, a mixing amount is set so that the atomic ratio of silicon to carbon is Si / C = 0.05 to 4 to prepare a slurry containing resins as a carbon source and silicon powder.

  As the resins contained in the slurry, at least one of phenol resin, furan resin, organometallic polymer, sucrose, and the like can be used.

  Silicon powder containing silicon powder or at least one metal such as magnesium, aluminum, titanium, chromium, manganese, iron, cobalt, nickel, copper, zinc, zirconium, niobium, molybdenum, and tungsten as a silicon raw material contained in the slurry An alloy or a mixture of this one kind of silicon alloy and silicon powder can be used.

  Carbon powder, graphite powder, carbon black, and the like can be added to the slurry as additives.

  In addition, one or more of silicon carbide, silicon nitride, zirconia, zircon, alumina, silica, mullite, molybdenum disilicide, boron carbide, boron powder, and the like may be added to the slurry as an aggregate or an antioxidant. it can.

  The slurry is impregnated with a sponge-shaped holding material having a skeleton formed of resin, rubber, paper, or the like and having continuous air holes so that the continuous air holes are not blocked. For example, it is also a preferable method to remove excess slurry by squeezing a sponge-shaped holding material. Next, the sponge-shaped holding material to which the slurry is attached is closely adhered to and bonded to the honeycomb structure or the outer peripheral wall molded body so as to have a desired final shape.

  Next, the sponge-shaped holding material to which the slurry is attached, and the honeycomb structure or the joined body to which the outer peripheral wall is joined are fired at 900 to 1350 ° C. in a vacuum or an inert atmosphere, A porous porous structure is produced. Then, silicon is reactively sintered to the carbonized porous structure at a temperature of 1350 ° C. or higher. Then, the three-dimensional network structure part 11 can be produced by melt-impregnating silicon at a temperature of 1300 to 1800 ° C. in a vacuum or an inert atmosphere.

  Silicon or silicon alloy containing at least one metal such as magnesium, aluminum, titanium, chromium, manganese, iron, cobalt, nickel, copper, zinc, zirconium, niobium, molybdenum and tungsten as silicon for melt impregnation Alternatively, a mixture of this one kind of silicon alloy and silicon can be used.

  The 1st fluid distribute | circulated to the heat exchange member 10 of this invention is not specifically limited, such as gas and a liquid. For example, if it is gas, the exhaust gas of a motor vehicle etc. are mentioned. In addition, the second fluid is not particularly limited as a medium such as gas or liquid. However, since the first fluid circulation part 5 and the second fluid circulation part 6 are constituted by the plurality of cells 3, the contact area is large and the thermal conductivity of the honeycomb structure 1 is also high. Even when both of the two fluids are gas, sufficient heat exchange can be performed, which is suitable for heat exchange between gas and gas.

  EXAMPLES Hereinafter, although this invention is demonstrated further in detail based on an Example, this invention is not limited to these Examples.

Example 1
(Manufacture of honeycomb structure)
A honeycomb structure 1 mainly composed of a Si-impregnated SiC composite material was produced as follows. First, a forming raw material kneaded with a predetermined amount of SiC powder, a binder, water, an organic solvent or the like was extruded into a desired shape and dried to obtain a honeycomb formed body. A part of the outer peripheral wall 7 and the partition wall 4 were deleted from the obtained honeycomb formed body, and processed into a shape having two constricted portions (constricted portions 16). Then, the honeycomb formed body was impregnated with metal Si in a reduced pressure inert gas or vacuum. The honeycomb structure 1 manufactured in this way is a dense material in which metal Si is filled in the gaps between the SiC particles, and has a high thermal conductivity of about 150 W / (m · K). .

The honeycomb structure 1 had a diameter of 60 mm and a length of 200 mm, and the cell structure portion had a partition wall thickness t _{a of} about 0.5 mm and a cell pitch of about 3.6 mm. Moreover, the cross-sectional shape perpendicular | vertical to the axial direction 9 of the whole 1st fluid distribution | circulation part 5 in the part in which the constriction part 16 was formed was a square of 30 mm x 30 mm (in XX 'sectional drawing of FIG. 4B). The cross-sectional shape of the first fluid circulation part 5 is a square). The length Lb of the constricted portion 16 is 20 mm, and the upper and lower constricted portions 16 are arranged at a position 30 mm from a position La 10 mm from the end face 2. The intermediate wall 8 was the same thickness as the other partition walls 4.

(Production of fluid circuit)
The heat insulating mat was wound around the outer peripheral surface of the honeycomb structure 1 and then press-fitted into the metal tube 12 made of stainless steel and having two through holes 21 for introducing a fluid disposed in advance on the outer peripheral surface. At the time of press-fitting, setting was made so that the cross section in which the through hole 21 of the metal pipe 12 was arranged was arranged in the cross section of the constricted portion of the honeycomb structure 1. Thereafter, a shielding plate 17 made of stainless steel was installed so as to close the outer peripheral portions of the both end faces 2 of the honeycomb structure 1 and fixed to the metal tube 12 by welding.

(Heat exchange efficiency test)
The first fluid flows from the first end face 2a of the honeycomb structure 1 and passes through the cell 3 (first fluid circulation portion 5) in the vicinity of the center of the cross section of the honeycomb structure 1 from the second end face 2b. It was discharged. On the other hand, the second fluid is disposed on the outer peripheral surface of the metal tube 12 and flows from the through hole 21 on the side close to the first end surface 2a, passes through the second fluid circulation portion 6 of the honeycomb structure 1, The heat transfer efficiency was measured by discharging from the through hole 21 on the side close to the second end face 2b.

As the first fluid, atmospheric gas at 400 ° C. was used and flowed into the cell 3 at SV (space velocity) 50000 h ⁻¹ . Moreover, 30 degreeC atmospheric gas was used as a 2nd fluid, and it flowed in the cell 3 at SV (space velocity) 50000h- ¹ . The temperature of the first fluid flowing 20 mm upstream from the inlet end face (first end face 2 a) of the honeycomb structure 1 is “inlet gas temperature 1”, and 200 mm downstream from the outlet end face (second end face 2 b) of the honeycomb structure 1. The temperature of the first fluid flowing through was set as “outlet gas temperature 1”. Further, the temperature of the second fluid flowing 20 mm upstream from the inflow portion 14 (referenced to the position of the outer peripheral surface of the outer peripheral wall 7) of the honeycomb structure 1 is “inlet gas temperature 2”, and the discharge portion 15 ( The temperature of the second fluid flowing 200 mm downstream from the position of the outer peripheral surface of the outer peripheral wall 7 was defined as “exit gas temperature 2”.
Heat exchange efficiency (%) = (exit gas temperature 2−inlet gas temperature 2) / (inlet gas temperature 1−inlet gas temperature 2) × 100

(Pressure loss measurement)
Under the same test conditions as in the heat exchange efficiency test, the pressure difference between the first end surface 2a of the honeycomb structure 1 and the 300 mm upstream portion from the second end surface 2b and the 300 mm downstream portion is measured. " Further, the pressure difference between the 300 mm upstream portion from one through hole 21 of the metal tube 12 and the 300 mm downstream portion from the other through hole 21 was measured, and was set as “pressure loss 2”.

(Heat resistance test)
Except for using 700 ° C, 800 ° C, or 900 ° C atmospheric gas as the first fluid, the test conditions were the same as in the heat exchange efficiency test, and the honeycomb structure 1 after the test was checked for cracks and breakage. .

(Example 2)
(Manufacture of honeycomb structure)
In the same manner as in Example 1, a honeycomb structure 1 was produced. The thermal conductivity was about 150 W / (m · K).

The honeycomb structure 1 had a diameter of 60 mm and a length of 200 mm, and the cell structure portion had a partition wall 4 thickness of about 0.5 mm and a cell pitch of about 3.6 mm. However, the thickness t _b of the intermediate wall 8 has set the shape during extrusion such that the 3 mm. Moreover, the cross-sectional shape perpendicular | vertical to the axial direction 9 of the whole 1st fluid distribution | circulation part 5 in the part in which the constriction part 16 was formed was a square of 30 mm x 30 mm (in XX 'sectional drawing of FIG. 4B). The cross-sectional shape of the first fluid circulation part 5 is a square). The length Lb of the constricted portion 16 is 20 mm, and the upper and lower constricted portions 16 are arranged at a position 30 mm from a position 10 mm from the end face 2.

  The production of the fluid circuit, the heat exchange efficiency test, the pressure loss measurement, and the heat resistance test are the same as in Example 1.

(Example 3)
(Manufacture of honeycomb structure)
In the same manner as in Example 1, a honeycomb structure 1 was produced. The thermal conductivity was about 150 W / (m · K).

The honeycomb structure 1 has a diameter of 60 mm and a length of 200 mm, and the cell structure portion has a partition wall 4 thickness of about 0.5 mm and a cell pitch of about 3.6 mm. However, the thickness t _b of the intermediate wall 8 has set the shape during extrusion such that the 3 mm. Moreover, the cross-sectional shape perpendicular to the axial direction 9 of the entire first fluid circulation portion 5 in the portion where the constricted portion 16 is formed is a circle having a diameter of 40 mm (in the XX ′ cross-sectional view of FIG. 4B). The cross-sectional shape of the first fluid circulation part 5 is circular). The length Lb of the constricted portion 16 is 20 mm, and the upper and lower constricted portions 16 are arranged at a position 30 mm from a position 10 mm from the end face 2.

  The production of the fluid circuit, the heat exchange efficiency test, the pressure loss measurement, and the heat resistance test are the same as in Example 1.

( Reference Example 1 )
(Manufacture of honeycomb molded body)
A forming raw material kneaded with a predetermined amount of SiC powder, a binder, water, an organic solvent or the like was extruded into a desired shape and dried to obtain a honeycomb formed body.

(Manufacture of ceramic structures including three-dimensional network structure)
A ceramic structure including a three-dimensional network structure part and containing Si-impregnated SiC composite material as a main component was produced as follows. First, a slurry containing a predetermined amount of resins and silicon powder was prepared. A sponge-like holding material having a skeleton formed of resin and having continuous air holes was impregnated with slurry to such an extent that the continuous air holes were not blocked. Next, the honeycomb structure and the molded body of the outer peripheral wall were adhered and bonded to the sponge-shaped holding material to which the slurry was adhered so as to have a desired final shape. The obtained joined body was impregnated with metal Si in a reduced-pressure inert gas. The ceramic structure produced in this way is a dense material in which metal Si is filled in the gaps between the SiC particles, and has a high thermal conductivity of about 150 W / (m · K).

The honeycomb structure 1 has a diameter of 40 mm and a length of 200 mm, and the cell structure portion has a partition wall 4 thickness of about 0.5 mm and a cell pitch of about 3.6 mm. The three-dimensional network structure 11 is disposed on the outer periphery of the honeycomb structure (FIG. 7), has a diameter of 60 mm, a length of 200 mm, a pore diameter of 3 mm, an open porosity of 95%, and a density of 0.1 g / cm ^3. The average branch diameter was about 0.5 mm, and the average aperture ratio was about 70%.

  The production of the fluid circuit, the heat exchange efficiency test, the pressure loss measurement, and the heat resistance test are the same as in Example 1.

(Comparative Example 1)
(Manufacture of honeycomb structure)
A honeycomb structure 1 mainly composed of a Si-impregnated SiC composite material was produced as follows. First, a forming raw material kneaded with a predetermined amount of SiC powder, a binder, water, an organic solvent or the like was extruded into a desired shape and dried to obtain a honeycomb formed body. With respect to the opening portions of the both end faces 2 of the obtained honeycomb formed body, every other layer was sealed by 5 mm in the axial direction 9 from both end faces 2 using the same raw material as the formed body. Thereafter, through holes 22 were made on the outer peripheral surface of the honeycomb structure 1 for the rows where both end faces 2 were sealed, so that fluid could pass (see FIG. 12). Then, the honeycomb formed body was impregnated with metal Si in a reduced pressure inert gas or vacuum. The honeycomb structure 1 manufactured in this way is a dense material in which metal Si is filled in the gaps between the SiC particles, and has a high thermal conductivity of about 150 W / (m · K). .

The shape of the honeycomb structure 1, diameter 60 mm, a length of 200 mm, the cell structure portion, the thickness _{t a} of the partition wall 4 was about 0.5 mm, the cell pitch of about 3.6 mm. As for the through holes 22 on the outer peripheral surface, the through holes 22 on the first end surface 2a side and the through holes 22 on the second end surface 2b side of the honeycomb structure 1 are arranged on the outer peripheral surface on the opposite side. By arranging the through holes 22 in this way, the fluid flowing from the through holes 22 on one outer peripheral surface side passes through the axial direction 9 of the honeycomb structure 1 and is discharged from the through holes 22 on the other outer peripheral surface. It becomes a structure like this. The hole shape of the through hole 22 is 20 mm from the end surface 2 of the honeycomb structure 1 to the 25 mm position, that is, 20 mm in the axial direction 9 and has a width of 3 mm.

(Production of fluid circuit)
The honeycomb structure 1 was arranged in a stainless casing having a cross-shaped shape and having two sets of flow passage inlet / outlet pipes. At that time, both end faces 2 of the honeycomb are directed to one flow path inlet A-exit A ′, and the through holes 22 arranged on the outer peripheral surface of the honeycomb structure 1 are directed to the other flow path inlet B-exit B ′. (FIG. 12).

(Heat exchange efficiency test)
The first fluid was introduced from the flow path inlet A of the casing, passed from the first end face 2a of the honeycomb structure 1 to the second end face 2b, and discharged from the flow path outlet A ′ of the casing. On the other hand, the second fluid is introduced from the flow passage inlet B of the casing, passed from one outer peripheral surface of the honeycomb structure 1 to the other outer peripheral surface, and discharged from the flow passage outlet B ′ of the casing, thereby achieving heat transfer efficiency. Was measured. As the first fluid, atmospheric gas at 400 ° C. was used and flowed into the cell 3 at SV (space velocity) 50000 h ⁻¹ . Moreover, 30 degreeC atmospheric gas was used as a 2nd fluid, and it flowed in the cell 3 at SV (space velocity) 50000h- ¹ .

The temperature of the first fluid flowing 20 mm upstream from the inlet end face (first end face 2 a) of the honeycomb structure 1 is “inlet gas temperature 1”, and 200 mm downstream from the outlet end face (second end face 2 b) of the honeycomb structure 1. The temperature of the first fluid flowing through was set as “outlet gas temperature 1”. The temperature of the second fluid flowing 20 mm upstream from the inlet outer peripheral surface of the honeycomb structure 1 is “inlet gas temperature 2”, and the temperature of the second fluid flowing 200 mm downstream from the outlet outer peripheral surface of the honeycomb structure 1 is “outlet gas”. Temperature 2 ”.
Heat exchange efficiency (%) = (exit gas temperature 2−inlet gas temperature 2) / (inlet gas temperature 1−inlet gas temperature 2) × 100

(Pressure loss measurement)
Under the same test conditions as in the heat exchange efficiency test, the pressure difference between the first end surface 2a of the honeycomb structure 1 and the 300 mm upstream portion from the second end surface 2b and the 300 mm downstream portion is measured. " Further, the pressure difference between the 300 mm upstream portion from one outer peripheral surface of the honeycomb structure 1 and the 300 mm downstream portion from the other outer peripheral surface was measured, and was set as “pressure loss 2”.

(Heat resistance test)
Except for using 700 ° C, 800 ° C, or 900 ° C atmospheric gas as the first fluid, the test conditions were the same as in the heat exchange efficiency test, and the honeycomb structure 1 after the test was checked for cracks and breakage. .

(result)
Regarding the pressure loss, both the pressure loss 1 and the pressure loss 2 were lower in Examples 1 to 3 and Reference Example 1 than in Comparative Example 1. Although there was no significant difference between Example 1 and Example 2, Example 3 had the lowest pressure loss. In pressure loss 2, Reference Example 1 had the second highest pressure loss after Comparative Example 1. On the other hand, regarding the result of the heat resistance test, in Comparative Example 1, the first and second fluids were broken in the sealability at 700 ° C. or higher, whereas in Example 1, the heat resistance test was 800 ° C. or higher. Although cracking occurred under the conditions, the conditions under which the sealing performance was destroyed were 900 ° C. or more. Regarding Example 2, although cracking occurred at 800 ° C. or higher, no gas leak was observed even at 900 ° C. Regarding Example 3, neither cracking nor gas leakage was confirmed even at 900 ° C. Regarding Reference Example 1 , the result was the same as Example 3. Regarding the heat exchange efficiency, the levels of Examples 1 to 3 and Comparative Example 1 were almost the same level, but Example 3 was slightly higher in efficiency. On the other hand, Reference Example 1 was more efficient than other levels.

From the above results, it was confirmed that in Examples 1 to 3, the heat exchange performance was comparable to that in Comparative Example 1, but the structure was low pressure loss and strong against thermal shock. Further, it was confirmed that the sealing property between fluids was easily maintained even when cracking due to thermal shock occurred. Moreover, it was confirmed that Example 3 is the most preferable structure among Examples 1-3. On the other hand, it was confirmed that the reference example 1 had a heat exchange performance higher than that of the comparative example 1, a low pressure loss, and a structure resistant to thermal shock. In addition, compared with Example 3, it was confirmed that although the pressure loss increases, the efficiency can be greatly surpassed.

  The heat exchange member of the present invention is not particularly limited as long as it is used for heat exchange between a heated body (high temperature side) and a heated body (low temperature side), and can be used in the automotive field, chemical field, pharmaceutical field, and the like. In particular, it is suitable when both the heating body and the heated body are gases. The ceramic structure of the present invention can produce a heat exchange member having excellent heat exchange efficiency.

1: honeycomb structure, 2, 2a, 2b: end face (in the axial direction), 3: cell, 4: partition, 5: first fluid circulation part, 6: second fluid circulation part, 7: outer peripheral wall, 8: Intermediate wall, 9: axial direction (longitudinal direction), 10: heat exchange member, 11: three-dimensional network structure part, 12: metal pipe, 13: intermediate material, 14: inflow part, 15: discharge part, 16: constricted part , 17: shielding plate, 18: plugged portion, 21: through hole (of the metal pipe), 22: through hole (of the honeycomb structure), 23: merge portion, 24: branch portion, 25: minimum branch diameter, 30: Ceramic structure.

Claims (15)

A three-dimensional network structure part having partition walls and / or continuous air holes that partition and form cells of 2 × 2 rows or more that serve as a first fluid flow part that is a flow path of the first fluid;
A partition wall and / or the three-dimensional network structure section that defines a plurality of cells that serve as a second fluid circulation section, which is a flow path of the second fluid, on the outer periphery via an intermediate wall;
Furthermore, it has an outer peripheral wall on its outer periphery,
An inflow portion for allowing the second fluid to flow into the second fluid circulation portion from the outside, and a discharge portion for discharging the second fluid flowing into the second fluid circulation portion to the outside are provided on the outer peripheral wall. A ceramic structure mainly composed of ceramics provided at least one or more pairs in part,
The inflow part or the discharge part of the second fluid is bundled without forming a part of the outer peripheral wall of the ceramic structure and a part of the partition wall and / or the three-dimensional network structure part. Configured as a constricted part
The constricted portion is not formed at an end portion in the axial direction of the ceramic structure, but is formed at a portion other than the end portion, and the outer peripheral wall and the partition and / or the three-dimensional network structure are formed at the end portion. Part is formed,
A heat exchange member capable of exchanging heat via a partition wall existing between the first fluid circulation part and the second fluid circulation part without mixing the first fluid and the second fluid.   The heat exchange member according to claim 1, wherein a metal tube is fitted to at least a part of the outer periphery of the ceramic structure.   The heat exchange member according to claim 2, further comprising an intermediate member made of a material having a Young's modulus lower than that of the metal tube, which is sandwiched between the metal tube and the ceramic structure.   The heat exchange member according to any one of claims 1 to 3, wherein the inflow portion or the discharge portion of the second fluid is configured by the three-dimensional network structure portion.   The heat exchange member according to any one of claims 1 to 4, wherein a cross-sectional shape perpendicular to the axial direction of the entire first fluid circulation portion in the portion where the constricted portion is formed is a square or a circle. .   The thickness of at least one part of the said intermediate wall which is a partition which exists between said 1st fluid circulation part and said 2nd fluid circulation part is thicker than another partition. The heat exchange member as described in.   The shielding board is arrange | positioned at the both ends of the said 2nd fluid circulation part of the said ceramic structure so that said 1st fluid and said 2nd fluid may not mix. The heat exchange member as described in.   The plug of any one of claims 1 to 6, wherein a part of the second fluid circulation portion of the ceramic structure is sealed so that the first fluid and the second fluid are not mixed. The heat exchange member according to Item 1.   The heat exchange member according to any one of claims 1 to 8, wherein the ceramic structure has a thermal conductivity of 100 W / (m · K) or more.   The heat exchange member according to any one of claims 1 to 9, wherein the ceramic structure includes silicon carbide as a main component.   The heat exchange member according to any one of claims 1 to 10, wherein the three-dimensional network structure portion has a thermal conductivity of 100 W / (m · K) or more.   The heat exchange member according to any one of claims 1 to 11, wherein a main component of the three-dimensional network structure is silicon carbide. A honeycomb structure having a partition , a plurality of cells penetrating from one end face to the other end face by the partition , and further having an outer peripheral wall on the outer periphery of the partition,
Among the plurality of cells, an intermediate wall that surrounds the cell in the central portion in the radial direction and is divided into the cell in the central portion and the cell in the remaining outer peripheral portion, and is thicker than the partition With
The main component is silicon carbide, the thermal conductivity is 100 W / (m · K) or more,
In the radial direction, at least two constricted portions in which the partition walls are not formed in the outer peripheral portion of the intermediate wall are provided apart in the axial direction, and the constricted portions are end portions in the axial direction of the honeycomb structure. A ceramic structure which is a honeycomb structure which is not formed in any of the above-described cases but is formed at a portion other than the end portion, and the outer peripheral wall and the partition walls are formed at the end portion.   14. The ceramic structure according to claim 13, wherein the constricted portion has a cross-sectional area of the constricted portion of 0.2 to 0.8 times the cross-sectional area of the other portion.   The ceramic structure according to claim 13 or 14, wherein a thickness of the intermediate wall is 1.2 to 15 times based on the other partition walls.