JP5819838B2 - Heat exchange member - Google Patents

Description

  The present invention relates to a heat exchange member used by being mounted on a heat exchanger.

  When a fluid (gas, liquid) is heated or cooled, a heat exchanger may be used. In the heat exchanger, a high-temperature fluid and a low-temperature fluid are separated from each other by a heat conductive flow path wall, and heat is transferred to the flow path wall so that heat exchange between both fluids is performed. In such a heat exchanger, the efficiency of heat exchange can be increased by increasing the area of the flow path wall that separates the high-temperature fluid and the low-temperature fluid. Therefore, a heat exchanger having a structure in which a high-temperature fluid and a low-temperature fluid are separated by a wave-shaped channel wall has been devised for the purpose of increasing the area of the channel wall. For the same purpose, each of the flow path of the high-temperature fluid and the flow path of the low-temperature fluid is branched into a plurality of flow paths, and the branched high-temperature flow path and the low-temperature flow path are alternately arranged. A heat exchanger having the structure described above has been devised.

  In such a heat exchanger, the channel wall continues to be exposed to the fluid, and may corrode depending on the nature of the fluid. In view of this, for a heat exchanger, a technique for improving the corrosion resistance by using a ceramic channel wall has been proposed (for example, Patent Document 1).

JP 61-24997 A

  However, in the proposed technology, when the ceramic flow path wall receives heat, it contracts and expands (causes thermal stress), and sometimes the flow path wall may be damaged by this thermal stress. In particular, if a high-temperature fluid and a low-temperature fluid are mixed due to breakage of the flow path wall, the function as a heat exchanger is impaired.

  In view of the above problems, an object of the present invention is to provide a technique for suppressing breakage due to thermal stress while maintaining heat exchange efficiency and corrosion resistance.

  The present invention is a heat exchange member shown below.

[1] A cylindrical outer peripheral wall having a porosity of 10% or less made of ceramics mainly composed of Si-impregnated SiC impregnated with metal Si, and a plurality of first fluid flow paths inside the outer peripheral wall A partition wall having a porosity of 10% or less, the partition wall being made of ceramics mainly composed of Si-impregnated SiC impregnated with metal Si, wherein the outer peripheral wall and the partition wall are the inner part of the outer peripheral wall. In the cross section perpendicular to the thickness T of the outer peripheral wall and the axial direction of the outer peripheral wall, the heat exchange between the first fluid flowing through the second fluid and the second fluid flowing outside the outer peripheral wall is interposed. the diameter D of the equivalent circle is calculated from the internal area of the peripheral wall, and the thickness t of the partition wall meets the following formulas (1) to (3), containing said metal Si in the outer peripheral wall and said partition wall The sum of the amount and the SiC content The heat exchange member whose ratio [metal Si content / (metal Si content + SiC content)] of the metal Si is 0.25 to 0.5 .
Formula (1): 0.3 mm <= T <= 4.0mm
Formula (2): 15 mm ≦ D ≦ 120 mm
Formula (3): 0.04 × T ≦ t ≦ 0.6 mm

[2] The thickness T of the outer peripheral wall, the diameter D of the equivalent circle calculated from the inner area of the outer peripheral wall in the cross section perpendicular to the axial direction of the outer peripheral wall, and the thickness t of the partition wall The heat exchange member according to [1], which satisfies (4) to (6).
Formula (4): 0.5 mm ≦ T ≦ 4.0 mm
Formula (5): 30 mm ≦ D ≦ 60 mm
Formula (6): 0.04 * T <= t <= 0.6mm

[3] The heat exchange member according to [1] or [2], wherein the cross-sectional shape of the cell is a polygon formed from an obtuse angle.

[4] The heat exchange member according to any one of [1] to [3], wherein at least one of the outer peripheral wall and the partition wall is dense.

[5] A coating that covers the outer peripheral wall so that the first fluid and the second fluid are separated from each other and heat exchange can be performed between the first fluid and the second fluid. The heat exchange member according to any one of [1] to [4], which includes a member.

  According to the heat exchange member of the present invention, damage due to thermal stress can be suppressed while maintaining heat exchange efficiency and corrosion resistance.

It is a perspective view of one embodiment of a heat exchange member of the present invention. It is the front view which looked at the heat exchange member shown in FIG. 1 from the one edge part side. It is a schematic diagram of the heat exchanger with which the heat exchange member of FIG. 1 was mounted. FIG. 4 is a cross-sectional view taken along line A-A ′ in FIG. 3. FIG. 4 is a B-B ′ sectional view in FIG. 3. It is a perspective view of the modification of one Embodiment of the heat exchange member of this invention. It is a perspective view of the other modification of one Embodiment of the heat exchange member of this invention. It is an enlarged view of one edge part of the heat exchange member whose cross-sectional shape of a cell is a hexagon. It is an enlarged view of one edge part of the heat exchange member which has a notch in a partition. It is the figure which expanded a part of cross section of the heat exchange member which has a notch in an outer peripheral wall. It is the figure which expanded a part of cross section of the heat exchange member from which the thickness of a partition differs between a center side and an outer peripheral side.

  Embodiments of the present invention will be described below. 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 present invention.

  The heat exchange member of the present invention partitions and forms a cylindrical outer peripheral wall made of ceramics containing SiC as a main component and a plurality of cells serving as a flow path for the first fluid inside the outer peripheral wall. And partition walls made of ceramics.

  In the heat exchange member of the present invention, when the first fluid is allowed to flow inside the outer peripheral wall and the second fluid is allowed to flow further to the outside of the outer peripheral wall, the outer peripheral wall and the partition wall are the first fluid and the second fluid. Intervene heat exchange between.

  In the heat exchange member of the present invention, the first fluid is distributed to the plurality of cells. When the first fluid is distributed to each cell in this way, the first fluid can be allowed to flow while contacting the partition wall surrounding each cell, and as a result, heat exchange can be performed between the first fluid and the partition wall. Can do. Furthermore, the heat exchange between the first fluid and the second fluid is finally performed through the heat conduction in the partition wall and the outer wall and the heat exchange between the outer wall and the second fluid. be able to.

  In particular, in the heat exchange member of the present invention, the first fluid is distributed to a plurality of cells, and the heat exchange between the first fluid and the partition wall is actively performed in each cell. The heat exchange efficiency between the first fluid and the second fluid is increased, and as a result, the heat exchange efficiency between the first fluid and the second fluid is enhanced.

  In the heat exchange member of the present invention, the outer peripheral wall and the partition wall are made of ceramics mainly composed of SiC, so that they have excellent corrosion resistance and high thermal conductivity. Such an outer peripheral wall or partition wall having high thermal conductivity is unlikely to cause a temperature difference between parts. That is, in each of the outer peripheral wall and the partition wall, the temperature difference between the highest temperature portion and the lowest temperature portion can be reduced. Therefore, in the heat exchange member of this invention, it can suppress that a big difference arises in the degree of shrinkage | contraction and expansion for every part in an outer peripheral wall or a partition. That is, in the heat exchange member of the present invention, the outer peripheral wall and the partition walls are made of ceramics whose main component is SiC, so that it is possible to suppress the occurrence of large thermal stresses on the outer peripheral wall and the partition walls. As a result, in the heat exchange member of the present invention, the occurrence of cracks and cracks due to thermal stress is suppressed in the outer peripheral wall and the partition wall.

  The ceramic mainly composed of SiC referred to in the present specification means a ceramic containing 50 mass% or more of SiC. For example, a partition wall made of ceramics containing SiC as a main component means a partition wall containing SiC by 50 mass% or more.

Furthermore, in the heat exchange member of the present invention, the thickness T of the outer peripheral wall, the diameter D of the equivalent circle calculated from the area inside the outer peripheral wall in the cross section perpendicular to the axial direction of the outer peripheral wall, and the thickness t of the partition wall The following formulas (1) to (3) are satisfied.
Formula (1): 0.3 mm <= T <= 4.0mm
Formula (2): 15 mm ≦ D ≦ 120 mm
Formula (3): 0.04 × T ≦ t ≦ 0.6 mm

  In the heat exchange member of the present invention, the rigidity of the outer peripheral wall is enhanced by the thickness T of the outer peripheral wall satisfying 0.3 mm ≦ T ≦ 4.0 mm. By increasing the rigidity of the outer peripheral wall in this way, in the heat exchange member of the present invention, the outer peripheral wall is less likely to be damaged, and as a result, the first fluid flowing inside the outer peripheral wall and the outer peripheral wall due to the outer peripheral wall being damaged. The problem of mixing with the second fluid flowing outside is less likely to occur.

  Moreover, in the heat exchange member of this invention, even if the crack and crack by a thermal stress arise in a partition from satisfy | filling the relationship of Formula (1)-(3) mentioned above, such a crack and crack have heat exchange efficiency. It is possible to suppress enlargement to such an extent that it is greatly reduced. Furthermore, when satisfy | filling the relationship of Formula (1)-(3) mentioned above, the pressure loss at the time of a 1st fluid flowing through the inside (specifically the inside of a cell) of an outer peripheral wall can be suppressed.

In the heat exchange member of the present invention, the thickness T of the outer peripheral wall, the diameter D of the equivalent circle calculated from the area of the outer peripheral wall in the cross section perpendicular to the axial direction of the outer peripheral wall, and the thickness t of the partition wall are It is preferable to satisfy (4) to (6).
Formula (4): 0.5 mm ≦ T ≦ 4.0 mm
Formula (5): 30 mm ≦ D ≦ 60 mm
Formula (6): 0.04 * T <= t <= 0.6mm

  In the heat exchange member of the present invention, when the relations of the above formulas (4) to (6) are satisfied, the rigidity of the outer peripheral wall is further increased, and the outer peripheral wall is hardly cracked or cracked. However, cracks and cracks due to thermal stress are extremely unlikely to occur. Furthermore, in the heat exchange member of the present invention, when the outer peripheral wall has a cylindrical shape and satisfies the relations of the above formulas (4) to (6), the effect of suppressing the occurrence of cracks and cracks in the outer peripheral wall. In addition, the effect of suppressing the occurrence of cracks and cracks in the partition walls can be expressed more reliably, which is more preferable.

  The heat exchange member of the present invention is preferably a polygon in which the cross-sectional shape of the cell is an obtuse angle. In the case of such a polygonal cell cross-sectional shape, the difference in the rigidity of the partition wall is smaller when compared between the respective portions inside the outer peripheral wall. As a result, the difference in the magnitude of the thermal stress generated in the partition walls is reduced when compared between the respective portions inside the outer peripheral wall. Thus, when the variation in the magnitude of the thermal stress generated in the partition wall is reduced, the maximum stress generated in the partition wall inside the outer peripheral wall is reduced, and as a result, the occurrence of cracks and cracks in the partition wall can be more reliably suppressed. Become.

  In the heat exchange member of the present invention, it is preferable that at least one of the outer peripheral wall and the partition wall is dense, and it is more preferable that both the outer peripheral wall and the partition wall are dense. When the outer peripheral wall is dense, the outer peripheral wall has high thermal conductivity, and as a result, the heat exchange efficiency of the heat exchange member can be increased. Similarly, when the partition walls are dense, the partition walls have high thermal conductivity, and as a result, the heat exchange efficiency of the heat exchange member can be increased. Therefore, in the heat exchange member of the present invention, when both the outer peripheral wall and the partition wall are dense, the heat exchange efficiency of the heat exchange member can be more reliably increased.

  The term “dense” as used herein means that the porosity is 10% or less. In the heat exchange member of the present invention, when the partition wall or the outer peripheral wall is dense, the porosity is more preferably 5% or less. In addition, the porosity here means the porosity measured by the mercury intrusion method. For example, when the outer peripheral wall or partition wall is made of porous ceramics (porosity of 30% or more) whose main component is SiC, the thermal conductivity is about 20 W / m · K. On the other hand, when the outer peripheral wall and partition walls are made of a dense ceramic (porosity of 10% or less) containing SiC as a main component, the thermal conductivity can be increased to about 150 W / m · K.

  The heat exchange member of the present invention preferably has a covering member that covers the outer peripheral wall. The covering member is provided so as to separate the first fluid and the second fluid. In this way, even if the outer peripheral wall is damaged, mixing of the first fluid and the second fluid can be prevented. The covering member is provided on the heat exchange member in a state in which heat exchange is possible between the first fluid and the second fluid.

  In the heat exchange member of the present invention, the first fluid and the second fluid can be separated by a simple configuration of inside and outside the cylinder. Since the heat exchange member can have a simple structure of a cylindrical shape, a heat exchanger can be made by a simple assembly operation. For example, it is possible to easily assemble a heat exchanger by connecting a pipe to both ends of the heat exchange member of the present invention to form a first fluid flow path, and further covering the heat exchange member with a casing (heat Specific examples of assembling the exchanger will be described later).

  Hereinafter, specific embodiments of the heat exchange member of the present invention will be described with reference to the drawings, and the contents thereof will be described in detail.

  FIG. 1 is a perspective view of an embodiment of a heat exchange member of the present invention. As illustrated, the heat exchange member 1 of the present embodiment has a cylindrical outer peripheral wall 3. The outer peripheral wall 3 is open at both ends 9a and 9b. Therefore, it is possible to allow the first fluid to pass through the inside of the outer peripheral wall 3 using one of the end 9a and the end 9b as an inlet and the other as an outlet.

  Further, in the present embodiment, the inside of the outer peripheral wall 3 is partitioned by the partition walls 7 into a square lattice shape. Thereby, a plurality of cells 5 are formed inside the outer peripheral wall 3. Therefore, the heat exchange member of the present embodiment is a so-called honeycomb structure 20. In the present embodiment, the outer shape of the honeycomb structure 20 is cylindrical (columnar), but the outer shape of the honeycomb structure 20 is not limited to the cylindrical shape. For example, as a modification of the present embodiment, when the honeycomb structure 20 is viewed from a cross section perpendicular to the axial direction, the outer cross-sectional shape of the honeycomb structure 20 is an ellipse, a quadrangle, or other polygons. Also good.

  Furthermore, in the present embodiment, the partition walls 7 traverse the inside of the outer peripheral wall 3 straight, and both ends of these partition walls 7 are in contact with the outer peripheral wall 3. Thus, since the partition wall 7 and the outer peripheral wall 3 are in contact with each other, heat conduction can be performed between the partition wall 7 and the outer peripheral wall 3.

  Moreover, in the heat exchange member 1 of this embodiment, the outer peripheral wall 3 and the partition 7 are formed of ceramics whose main component is SiC.

  Moreover, the outer peripheral wall 3 and the partition 7 can also be made from ceramics whose main component is SiC impregnated with metal Si. In this case, the thermal conductivity of the outer peripheral wall 3 and the partition wall 7 can be further increased as the amount of impregnation with the metal Si is increased. For example, for ceramics mainly composed of SiC impregnated with metal Si, 100 parts by mass of ceramics mainly composed of SiC before impregnation with metal Si are impregnated with 30 parts by mass or more of metal Si. The conductivity can be 100 W / m · K or more.

Specifically, Si-impregnated SiC, (Si + Al) -impregnated SiC, metal composite SiC, recrystallized SiC, Si ₃ N ₄ , SiC, or the like can be used as the material of the outer peripheral wall 3 and the partition walls 7. However, when the outer peripheral wall 3 and the partition wall 7 made of the materials listed here are porous (porosity of 30% or more), high thermal conductivity may not be obtained. Therefore, in order to obtain a high heat exchange rate when Si-impregnated SiC, (Si + Al) -impregnated SiC, metal composite SiC, recrystallized SiC, Si ₃ N ₄ , SiC, or the like is used as the material of the outer peripheral wall 3 or the partition wall 7. The outer peripheral wall 3 and the partition wall 7 are preferably made dense (porosity of 10% or less).

  When making such a dense material, it is more preferable to use Si-impregnated SiC or (Si + Al) -impregnated SiC as the material of the outer peripheral wall 3 and the partition wall 7. The outer peripheral wall 3 and the partition walls 7 made of SiC impregnated with Si are densely formed and exhibit sufficient strength while exhibiting high thermal conductivity and heat resistance. For example, in the case of SiC (silicon carbide) porous (porosity of 30% or more), the thermal conductivity is about 20 W / m · K, but in the case of dense (porosity of 10% or less) made of Si-impregnated SiC. The thermal conductivity is improved to about 150 W / m · K.

Further, when the outer peripheral wall 3 and the partition wall 7 are made of Si-impregnated SiC, (Si + Al) -impregnated SiC, metal composite SiC, recrystallized SiC, Si ₃ N ₄ , SiC, or the like, the outer peripheral wall 3 or the partition wall 7 is heat resistant. It can be made excellent in thermal shock resistance, oxidation resistance, and corrosion resistance against acids and alkalis, and as a result, the heat exchange member 1 can withstand long-term use.

  Here, when the outer peripheral wall 3 and the partition wall 7 are mainly composed of Si-impregnated SiC or (Si + Al) -impregnated SiC, the ratio of the Si content to the sum of the Si content and the SiC content [Si content / (Si content + SiC content)] is preferably 0.05 to 0.5, and more preferably 0.1 to 0.4. When the ratio of the Si content to the sum of the Si content and the SiC content is 0.05 or more, the bonding between the SiC particles formed through the Si phase is sufficient, and the outer peripheral wall 3 and the partition walls 7 can be increased, and in addition to this, sufficient thermal conductivity can be obtained. When the ratio of the Si content to the sum of the Si content and the SiC content is 0.5 or less, the amount of the Si phase is not excessive, and as a result, the outer peripheral wall 3 is subjected to firing or the like. When forming the barrier rib 7, it is difficult to cause inconvenience such as deformation.

FIG. 2 is a front view of the end 9a of the heat exchange member 1 of the present embodiment. In this front view, the diameter T of the equivalent circle calculated from the thickness T of the outer peripheral wall 3 in the heat exchange member 1 of the present embodiment and the area of the outer peripheral wall 3 in the cross section perpendicular to the axial direction of the outer peripheral wall 3; And the thickness t of the partition wall 7 is shown.

  In the present embodiment, the outer peripheral wall 3 has a cylindrical shape with a uniform thickness. Further, when the heat exchange member 1 of the present embodiment is viewed from a cross section perpendicular to the axial direction, the cross-sectional shape inside the outer peripheral wall 3 is a circle. Therefore, the diameter D of the equivalent circle is the same as the inner diameter of the outer peripheral wall 3.

  When the shape of the outer peripheral wall is other than the cylindrical shape, the area of the region surrounded by the inner surface of the outer peripheral wall is obtained in a cross section perpendicular to the axial direction of the outer peripheral wall, and the diameter of a circle having the same area as this area is obtained. This is calculated and used as the diameter D of the equivalent circle.

  Next, a specific example of a heat exchanger equipped with the heat exchange member 1 of the present embodiment will be shown. A mode of heat exchange using the heat exchange member 1 of the present embodiment will be described with reference to the drawing of this heat exchanger.

  FIG. 3 shows a schematic diagram of a heat exchanger 21 equipped with the heat exchange member 1 shown in FIG. As illustrated, in the heat exchanger 21 of the present embodiment, the heat exchange member 1 described above is mounted in the casing 11. The casing 11 used here is formed into a rectangular parallelepiped box shape by a wall 19. In the heat exchanger 21 of the present embodiment, one hole is formed in each of the wall 19 on one surface of the casing 11 and the wall 19 on the surface opposite to this surface, and the end of the heat exchange member 1 is formed in these holes. The part 9a and the end part 9b are fitted. By doing so, the heat exchange member 1 is traversed inside the casing 11. Furthermore, in the heat exchanger 21 of the present embodiment, the end 9a and the end 9b of the heat exchange member 1 are connected to the tube 23a and the tube 23b on the outside of the wall 19, respectively. As a result, in the heat exchanger 21 of the present embodiment, when the first fluid is allowed to flow into the tube 23a, it can subsequently flow into the heat exchange member 1 and further into the tube 23b.

  FIG. 4 is a cross-sectional view taken along the line A-A ′ in FIG. 3. As shown in the drawing, when the first fluid flows inside the heat exchange member 1 (inside the outer peripheral wall 3), the first fluid is distributed to each of the plurality of cells 5.

  Further, as shown in FIG. 3, the casing 11 is provided with an inlet 13 for allowing the second fluid to flow into the casing 11 and an outlet 15 for discharging the second fluid from the casing 11 to the outside. .

  FIG. 5 is a cross-sectional view taken along the line B-B ′ in FIG. 3. As illustrated, when the second fluid flows into the casing 11 from the inlet 13, the second fluid flows while contacting the outer peripheral surface 4 of the outer peripheral wall 3 of the heat exchange member 1, and is finally discharged from the outlet 15. .

  Here, a rectangular parallelepiped box-shaped casing 11 is shown and described. However, as for the form of the casing, the flow path of the first fluid made by connecting a heat exchange member or a pipe to the heat exchange member. As long as the second fluid can flow on the outer periphery of the heat exchange member inside the casing.

  For example, if the first fluid is hot and the second fluid is cold, heat transfer occurs from the first fluid to the second fluid. In this heat transfer process, first, heat is transferred from the first fluid to the partition wall 7 and the outer peripheral wall 3, and then, heat is transferred from the outer peripheral wall 3 to the second fluid. At this time, heat transfer from the first fluid to the outer peripheral wall 3 is performed in the following two modes.

  Since the first fluid flowing through the cell 5 on the outermost peripheral side (for example, the cell 5 a in FIG. 5) is in contact with the outer peripheral wall 3, heat can be directly transferred to the outer peripheral wall 3.

  The first fluid flowing through other cells (for example, the cell 5 b and the cell 5 c in FIG. 5) can transfer heat to the outer peripheral wall 3 through the partition wall 7. For example, in the case of the first fluid flowing through the cell 5a in FIG. 5, first, heat is transferred from the first fluid to the partition wall 7 forming the cell 5a, and then the partition wall 7 of this cell 5a The heat can be transferred to the outer peripheral wall 3 by sequentially following the partition walls 7 forming the cells 5. Thus, even if the first fluid flows without contacting the outer peripheral wall 3, heat can be reliably transmitted to the outer peripheral wall 3 by utilizing the heat conduction of the partition wall 7.

  In the heat exchange member 1 of the present embodiment, for example, when a hole or a crack is generated in the partition wall 7 (the partition wall 7 separating the cell 5b and the cell 5c) indicated by a broken-line frame α in FIG. Since only the first fluids flowing through 5c are mixed with each other, it does not progress to a fatal failure that impairs the function as the heat exchange member. Therefore, in the heat exchange member 1 of the present embodiment, as a modification, it is easy to appropriately apply a form capable of realizing higher heat exchange efficiency such as making the partition wall 7 thin or making the partition wall 7 twisted.

  Furthermore, in the heat exchange member 1 of the present embodiment, the partition wall 7 also serves to structurally reinforce the outer peripheral wall 3 as a beam. Thus, since the partition wall 7 serves as a beam, the outer peripheral wall 3 is less likely to have a hole or a crack. Therefore, in the heat exchange member 1 of this embodiment, it is hard to produce the fatal failure which mixes a 1st fluid and a 2nd fluid.

  FIG. 6 is a perspective view of a modification of the present embodiment. The heat exchange member 100 of this modification includes a cylindrical metal tube 40 and a graphite sheet 45. In FIG. 6, a part of the metal tube 40 is cut away to expose the graphite sheet 45 inside the metal tube 40, and further, a part of the exposed graphite sheet 45 is cut away to form an inner side of the graphite sheet 45. The outer peripheral wall 3 is exposed as shown in FIG. As shown in the figure, in this modification, the honeycomb structure 20 is housed inside the metal tube 40 with the outer peripheral wall 3 covered with the graphite sheet 45.

  By covering the periphery of the outer peripheral wall 3 with the tube wall of the metal tube 40 in this way, even if the outer peripheral wall 3 is damaged and the first fluid may leak out of the outer peripheral wall 3, the leaked first This fluid is shielded by the tube wall of the metal tube 40, and the situation where the first fluid and the second fluid are mixed can be prevented.

  In particular, the heat between the outer peripheral wall 3 and the metal tube 40 is obtained by sandwiching the graphite sheet 45 between the outer peripheral wall 3 of the honeycomb structure 20 and the metal tube 40 as in the modification shown in FIG. Good exchange can be achieved. Due to the nature of the ceramic material, it may be difficult to completely smooth the surface of the outer peripheral wall 3, and the surface of the outer peripheral wall 3 in this case is uneven. When such an uneven outer peripheral wall 3 is placed inside the metal tube 40 without sandwiching the graphite sheet 45, the convex portions on the surface of the outer peripheral wall 3 and the metal tube 40 are only brought into contact with each other in a scattered manner. It becomes difficult to perform good heat conduction between the wall 3 and the metal tube 40. When the graphite sheet 45 is sandwiched between the outer peripheral wall 3 and the metal tube 40, the graphite sheet 45 can be deformed, so that the graphite sheet 45 can also enter the concave portion on the surface of the outer peripheral wall 3 to come into contact therewith. In this way, each of the outer peripheral wall 3 and the metal tube 40 can be brought into contact with the graphite sheet 45 in a wide range, and as a result, good heat conduction can be performed between the outer peripheral wall 3 -graphite sheet 45 and the metal tube 40. It becomes possible.

  FIG. 7 is a perspective view of another modification of the present embodiment. As shown in the figure, the heat exchange member 150 of the present modification has a square columnar outer peripheral wall 3 having a hollow inside. A plurality of cells 5 are formed inside the outer peripheral wall 3 by partitioning the inside of the outer peripheral wall 3 into a square lattice shape by the partition walls 7.

When the heat exchange member 150 of this modification is viewed from a cross section perpendicular to the axial direction, the cross-sectional shape inside the outer peripheral wall 3 is a square having a side length L (mm). Therefore, in this modification, the diameter D of the equivalent circle calculated from the area inside the outer peripheral wall 3 in the cross section perpendicular to the axial direction of the outer peripheral wall 3 is 2L / π ^1/2 (mm).

  FIG. 8 is an enlarged view of one end of the heat exchange member according to the embodiment of the present invention. As shown in the figure, in the heat exchange member 210 of the present embodiment, the cross-sectional shape of the cell 5 is a regular hexagon (a polygon having a cross-sectional shape of the cell of 120 degrees). When the cross-sectional shape of the cell is a polygon having an obtuse angle, the thermal stress generated in the partition wall 7 can be relaxed. As a result, the occurrence of cracks and cracks in the partition walls 7 can be suppressed.

  FIG. 9 is an enlarged view of one end of the heat exchange member according to the embodiment of the present invention. As shown in the figure, in the heat exchange member 220 of the present embodiment, there is a cut 31 in a part of the partition wall 7. The presence of the cut 31 in the partition wall 7 can relieve the thermal stress generated in the partition wall 7, and as a result, the occurrence of cracks and cracks in the partition wall 7 can be suppressed. In particular, by making a notch 31 in the vicinity of the portion of the partition wall 7 where the largest thermal stress is generated, the thermal stress generated in the partition wall 7 can be alleviated more effectively. It becomes possible to suppress generation | occurrence | production of a crack etc. still more reliably.

  FIG. 10 is a cross-sectional view of a heat exchange member according to an embodiment of the present invention. As shown in the figure, in the heat exchange member 230 of the present embodiment, there is a cut 33 in the outer peripheral wall 3. The presence of the cut 33 in the outer peripheral wall 3 can relieve thermal stress generated in the outer peripheral wall 3, and as a result, the occurrence of cracks and cracks in the outer peripheral wall 3 can be suppressed. In particular, as in the case of the notches 33 shown in FIG. 10, if the notches 33 are formed in the outer peripheral wall 3 where the plurality of partition walls 7 just intersect, the thermal stress generated in the plurality of partition walls 7 can be reduced. This is preferable because it becomes possible.

  FIG. 11 is a cross-sectional view of a heat exchange member according to an embodiment of the present invention. As shown in the figure, in the heat exchange member 240 of the present embodiment, the partition wall 7 in the central part inside the outer peripheral wall 3 is thin, and the partition wall 7 in the outer peripheral part is thick. When the partition wall 7 in the center portion inside the outer peripheral wall 3 is thinner than the partition wall 7 in the outer periphery portion, the thermal stress generated in the partition wall 7 in the center portion can be reduced. As a result, it is possible to suppress the occurrence of cracks and cracks in the partition wall 7 in the central portion. On the other hand, the partition wall 7 at the outer peripheral portion is thicker than the central portion, and thus there is a risk of generating a large thermal stress. However, since the partition wall 7 in the outer peripheral portion is close to the coupling portion between the partition wall 7 and the outer peripheral wall 3, the strength is reinforced by the outer peripheral wall 3. Therefore, the occurrence of cracks and cracks is also suppressed in the partition wall 7 in the outer peripheral portion.

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

(1) Heat exchange member (preparation of clay)
First, 70% by mass of SiC powder having an average particle size of 45 μm, 10% by mass of SiC powder having an average particle size of 35 μm, and 20% by mass of SiC powder having an average particle size of 5 μm were mixed to prepare a mixture of SiC powders. 100 parts by mass of this SiC powder mixture was mixed with 4 parts by mass of binder and water, and kneaded using a kneader to obtain a kneaded product. This kneaded material was put into a vacuum kneader to produce a columnar clay.

(Extrusion molding)
Next, the kneaded material was extruded to form a honeycomb formed body. In extrusion molding, the shape and thickness of the outer peripheral wall, the thickness of the partition walls, the shape of the cells, the cell density, and the like were made desired by selecting an appropriate form of die and jig. The base was made of a hard metal that does not easily wear. The honeycomb molded body was formed such that the outer peripheral wall was formed into a cylindrical shape or a hollow quadrangular prism shape, and the inside of the outer peripheral wall was divided into a square lattice shape by partition walls. Further, these partition walls were formed so as to be parallel to each other at equal intervals in the directions orthogonal to each other and to traverse the inside of the outer peripheral wall straight. Thereby, the cross-sectional shape of the cell other than the outermost peripheral portion inside the outer peripheral wall was made square.

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

(Degreasing, impregnation and firing of Si metal)
Next, the honeycomb formed body was degreased at 500 ° C. for 5 hours in a nitrogen atmosphere. Furthermore, a lump of metal Si was placed on the honeycomb structure obtained by such degreasing and fired at 1450 ° C. for 4 hours in an inert gas under vacuum or reduced pressure. During the firing, the lump of metal Si placed on the honeycomb structure was melted, and the outer peripheral wall and partition walls were impregnated with metal Si. When the thermal conductivity of the outer peripheral wall and the partition walls was set to 100 W / m · K, a mass of 70 parts by mass of metal Si was used with respect to 100 parts by mass of the honeycomb structure. Further, when the thermal conductivity of the outer peripheral wall and partition walls was set to 150 W / m · K, 80 parts by mass of metal Si mass was used with respect to 100 parts by mass of the honeycomb structure. Through such firing, a heat exchange member was obtained. In addition, about the more detailed form of a heat exchange member, it mentions when demonstrating each Example and each comparative example separately below.

(Examples 1-8, Comparative Examples 1 and 2)
A heat exchange member having a cylindrical outer peripheral wall having a structure basically the same as that shown in FIG. 1 was manufactured. Specifically, the total length is 100 mm, the outer peripheral wall thickness T is 1.0 mm, the partition wall thickness t is 0.5 mm, the cell density is 24 cells / cm ² , and the outer wall and partition wall thermal conductivity is 150 W / m · K. Thus, a heat exchange member having an equivalent circle diameter D (here, the same as the inner diameter of the outer peripheral wall) calculated from the area inside the outer peripheral wall as shown in Table 1 was manufactured.

(Examples 9-22, Comparative Examples 3-10)
A heat exchange member having a cylindrical outer peripheral wall having a structure basically the same as that shown in FIG. 1 was manufactured. Specifically, the total length is 100 mm, the diameter D of the equivalent circle calculated from the area inside the outer peripheral wall (here, the same as the inner diameter of the outer peripheral wall) is 45 mm, the cell density is 24 cells / cm ² , and the heat of the outer peripheral wall and the partition wall A heat exchange member having a conductivity of 150 W / m · K, the outer peripheral wall thickness T and the partition wall thickness t shown in Table 2 was manufactured.

(Examples 23 to 36, Comparative Examples 11 to 17)
A heat exchange member having a cylindrical outer peripheral wall having a structure basically the same as that shown in FIG. 1 was manufactured. Specifically, the total length is 100 mm, the diameter D of the equivalent circle calculated from the area inside the outer peripheral wall (here, the same as the inner diameter of the outer peripheral wall) is 45 mm, the cell density is 24 cells / cm ² , and the heat of the outer peripheral wall and the partition wall A heat exchange member having a conductivity of 100 W / m · K and having the outer peripheral wall thickness T and the partition wall thickness t shown in Table 3 was manufactured.

(Examples 37 to 44, Comparative Examples 18 and 19)
A heat exchange member having a quadrangular prism-shaped outer peripheral wall having basically the same structure as that shown in FIG. 7 was manufactured. Specifically, the total length is 100 mm, the outer peripheral wall thickness T is 1.0 mm, the partition wall thickness t is 0.5 mm, the cell density is 24 cells / cm ² , and the outer wall and partition wall thermal conductivity is 150 W / m · K. Thus, a heat exchange member in which the diameter D of the equivalent circle calculated from the area inside the outer peripheral wall is as shown in Table 4 was manufactured. In addition, when the heat exchange member was seen from a cross section perpendicular to the axial direction, the cross section inside the outer peripheral wall was a square, and the length of one side was set to the value shown in Table 4.

(2) Heat exchanger By housing the heat exchange members of the above-described embodiments and comparative examples in the casing, a heat exchanger (a heat exchanger having basically the same structure as that shown in FIG. 3) can be obtained. Produced. About the casing, the thing of the shape where the clearance gap between the outer peripheral wall of a heat exchange member and the wall surface of a casing becomes 1 mm in each part was used. That is, about the heat exchange member which has a cylindrical outer peripheral wall, it accommodated in the cylindrical casing (Examples 1-36, Comparative Examples 1-17). About the heat exchange member which has a square pillar-shaped outer peripheral wall, it accommodated in the rectangular parallelepiped box type casing (Examples 37-44, Comparative Examples 18 and 19). In addition, ten heat exchangers were produced for each example and each comparative example, and the following heat exchange tests and the like were performed on these ten heat exchangers.

(3) Heat Exchange Test In the heat exchanger described above, a heat exchange test was performed using nitrogen gas as the first fluid and water as the second fluid. The temperature of nitrogen gas was set to 500 ° C., the flow rate was set to 20 g / s, and the flow rate of water was set to 5 L / min. In addition, the heat exchange test includes the nitrogen gas outlet temperature (the temperature of the nitrogen gas immediately after being discharged from the end on the outlet side of the heat exchange member) and the water outlet temperature (the temperature of water when passing through the outlet of the casing). Was confirmed to stabilize.

The temperature of the first fluid immediately before flowing into the end portion on the inlet side of the heat exchange member is “inlet gas temperature”, and the temperature of the first fluid immediately after discharge from the end portion on the outlet side of the heat exchange member is “outlet gas temperature”. Was measured. The temperature of water passing through the inlet of the casing was measured as “inlet water temperature”. From these temperatures, the heat exchange efficiency (%) was calculated by the following formula. The results are shown in Tables 1-4.
Heat exchange efficiency (%) = (inlet gas temperature−outlet gas temperature) / (inlet gas temperature−inlet water temperature) × 100

(4) Measurement of pressure loss In the heat exchange test mentioned above, the pressure gauge was each arranged in the channel of nitrogen gas located before and behind the heat exchange member. The pressure loss of nitrogen gas flowing in the heat exchange member (in the cell) was measured from the differential pressure obtained from the measured values of these pressure gauges. About each Example and each comparative example, the average value of the pressure loss measured with the total 10 heat exchangers is shown to Tables 1-4.

(5) Inspection of breakage About each Example and each comparative example, after producing a total of 10 heat exchangers as described above and conducting a heat exchange test, heat exchange from each of these 10 heat exchangers The member was taken out, and the presence or absence of breakage in the partition walls or the outer peripheral wall was observed. Tables 1 to 4 show the number of heat exchange members that were damaged among the total 10 heat exchange members.

(6) Isostatic strength test A 0.5 mm thick urethane rubber sheet is wrapped around the outer wall of the heat exchange member, and a circular urethane rubber sheet is placed on both ends of the heat exchange member. An aluminum plate having a thickness of 20 mm was disposed between the two. The aluminum plate and urethane rubber sheet had the same shape and size as the end of the heat exchange member (for example, the outer peripheral wall is cylindrical, that is, the end is circular) (The aluminum disk was used for this). Furthermore, the test sample was obtained by sealing between the outer periphery of an aluminum board, and the urethane rubber sheet | seat by winding with a vinyl tape along the outer periphery of an aluminum board. The test sample was then placed in a pressure vessel filled with water. Subsequently, the water pressure in the pressure vessel was increased to 20 MPa at a rate of 0.3 to 3.0 MPa / min, and the water pressure when the heat exchange member was broken was measured. Tables 1 to 4 show the water pressure when the heat exchange member breaks. In addition, when destruction did not occur even at a water pressure of 20 MPa, it was described as “> 20” in Tables 1 to 4. Further, when the water pressure when the heat exchange member breaks is more than 1.0 MPa, it is determined that the isostatic strength is “possible” [indicated by circles (◯) in Tables 1 to 4], and the heat exchange member When the water pressure when fracture occurred was 1.0 MPa or less, the isostatic strength was determined to be “impossible” [indicated by a cross (×) in Tables 1 to 4].

(7) Comprehensive evaluation When satisfying the two conditions of “pressure loss of 70 kPa or less” and “isostatic strength exceeding 1.0 MPa”, the comprehensive evaluation was determined as “possible” [circles (◯) in Tables 1 to 4]. Indicated by]. In addition, when there is a condition that does not satisfy even one of the above two conditions, the comprehensive evaluation is determined to be “impossible” [in Tables 1 to 4, indicated by a cross (×)].

  The present invention can be used as a heat exchange member used by being mounted on a heat exchanger.

1: heat exchange member, 3: outer peripheral wall, 4: outer peripheral surface, 5, 5a to 5c: cell, 7: partition wall, 9, 9a, 9b: end, 11: casing, 13: (second fluid) Inlet, 15: (second fluid) outlet, 17: (second fluid) flow path, 19: wall, 20: honeycomb structure, 21: heat exchanger, 23a, 23b: pipe, 31: ( Notches of partition walls, 33: Notches of (outer peripheral wall), 40: Metal tube, 45: Graphite sheet, 100, 150, 210, 220, 230, 240: Heat exchange member.

Claims (5)

A cylindrical outer peripheral wall having a porosity of 10% or less, made of ceramics mainly composed of Si-impregnated SiC impregnated with metal Si;
A partition wall having a porosity of 10% or less made of ceramics mainly composed of Si-impregnated SiC impregnated with metal Si, which defines a plurality of cells serving as flow paths for the first fluid in the outer peripheral wall. Have
The outer peripheral wall and the partition wall intervene heat exchange between the first fluid flowing inside the outer peripheral wall and a second fluid flowing outside the outer peripheral wall;
The thickness T of the outer peripheral wall, the diameter D of the equivalent circle calculated from the inner area of the outer peripheral wall in the cross section perpendicular to the axial direction of the outer peripheral wall, and the thickness t of the partition wall are expressed by the following formula (1). It meets to (3),
The ratio of the metal Si content to the sum of the metal Si content and the SiC content in the outer peripheral wall and the partition wall [metal Si content / (metal Si content + SiC content)] is 0.25 to 0.25. A heat exchange member that is 0.5 .
Formula (1): 0.3 mm <= T <= 4.0mm
Formula (2): 15 mm ≦ D ≦ 120 mm
Formula (3): 0.04 × T ≦ t ≦ 0.6 mm The thickness T of the outer peripheral wall, the diameter D of the equivalent circle calculated from the inner area of the outer peripheral wall in the cross section perpendicular to the axial direction of the outer peripheral wall, and the thickness t of the partition wall are expressed by the following formula (4). The heat exchange member according to claim 1 satisfying (6).
Formula (4): 0.5 mm ≦ T ≦ 4.0 mm
Formula (5): 30 mm ≦ D ≦ 60 mm
Formula (6): 0.04 * T <= t <= 0.6mm   The heat exchange member according to claim 1 or 2, wherein the cross-sectional shape of the cell is a polygon composed of an obtuse angle.   The heat exchange member according to any one of claims 1 to 3, wherein at least one of the outer peripheral wall and the partition wall is dense.   A covering member is provided so as to separate the first fluid and the second fluid, and covers the outer peripheral wall so that heat can be exchanged between the first fluid and the second fluid. The heat exchange member according to any one of claims 1 to 4.

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