Heat transfer member and heat exchanger

Abstract

To provide a heat conductive member capable of improving the heat recovery efficiency.SOLUTION: Provided is a heat conductive member 100 that includes a honeycomb structure 10 having: an outer peripheral wall 11; and a plurality of partition walls 15 arranged inside the outer peripheral wall 11 and defining a plurality of cells 14 extending from a first end face 12 to a second end face 13 to form a flow path for a first fluid. In a cross section of the honeycomb structure 10 perpendicular to a flow path direction for the first fluid, the partition walls 15 include a plurality of first partition walls 15a extending in a radial direction and a plurality of second partition walls 15b extending in a circumferential direction. In at least a part of the first partition wall 15a, a portion defining the cell 14 closest to the outer peripheral wall 11 is thicker than a portion defining the cell 14 closest to the central portion.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a heat transfer member and a heat exchanger. [Background technology]

[0002] In recent years, there has been a demand for improved fuel economy in automobiles. In particular, to prevent a decline in fuel economy when the engine is cold, such as when starting the engine, there are hopes for systems that can quickly warm the coolant, engine oil, automatic transmission fluid (ATF), etc., thereby reducing friction loss. There are also hopes for systems that can heat exhaust gas purification catalysts to quickly activate them.

[0003] An example of such a system is a heat exchanger. A heat exchanger is a device that exchanges heat between a first fluid and a second fluid by circulating a first fluid inside the heat exchanger and a second fluid outside the heat exchanger. Such a heat exchanger can effectively utilize heat by exchanging heat from a high-temperature fluid (e.g., exhaust gas) to a low-temperature fluid (e.g., cooling water).

[0004] Known heat exchangers that recover heat from high-temperature gases such as automobile exhaust gases include a heat exchanger that uses a heat conduction member (also called a "heat exchange member") having a honeycomb structure that is disposed inside the outer peripheral wall and has first partition walls that extend radially and a plurality of second partition walls that extend circumferentially in a cross section perpendicular to the cell extension direction (Patent Documents 1 and 2). In this heat exchanger, heat exchange can be performed by circulating a first fluid within the cells of the honeycomb structure and a second fluid on the outer peripheral wall surface. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] International Publication No. 2019 / 135312 [Patent Document 2] Japanese Patent Application Publication No. 2019-120488 Summary of the Invention [Problem to be solved by the invention]

[0006] However, conventional honeycomb structures having first partition walls extending radially and multiple second partition walls extending circumferentially have a larger cell width on the outer wall side than on the center side, making it impossible to sufficiently recover heat in the cells on the outer wall side.

[0007] The present invention has been made to solve the above-mentioned problems, and provides a heat transfer member and a heat exchanger that can improve heat recovery efficiency. [Means for solving the problem]

[0008] The above problems are solved by the present invention, which is specified as follows:

[0009] The present invention provides a heat conduction member including a honeycomb structure having an outer peripheral wall and a plurality of partition walls disposed inside the outer peripheral wall, extending from a first end face to a second end face, and defining a plurality of cells that serve as flow paths for a first fluid, In a cross section of the honeycomb structure perpendicular to a flow path direction of the first fluid, the partition walls include a plurality of first partition walls extending in a radial direction and a plurality of second partition walls extending in a circumferential direction, At least a part of the first partition wall has a thickness of a portion that defines the cell closest to the outer peripheral wall greater than a thickness of a portion that defines the cell closest to the center. Ku, the partition walls include the first partition walls having portions adjacent to each other in the circumferential direction that have different thicknesses; It is a heat conductive member. The present invention also provides a heat conduction member including a honeycomb structure having an outer peripheral wall and a plurality of partition walls disposed inside the outer peripheral wall, extending from a first end face to a second end face, and defining a plurality of cells that serve as flow paths for a first fluid, In a cross section of the honeycomb structure perpendicular to a flow path direction of the first fluid, the partition walls include a plurality of first partition walls extending in a radial direction and a plurality of second partition walls extending in a circumferential direction, At least a portion of the first partition wall has a thickness of a portion that defines the cell and is closest to the outer peripheral wall, the thickness of a portion that defines the cell and is closest to a center portion, The honeycomb structure is a heat conduction member having two or more regions including the first partition walls whose thicknesses differ in the circumferential direction.

[0010] The present invention also provides a heat conduction member including a honeycomb structure having an outer peripheral wall, an inner peripheral wall, and partition walls disposed between the outer peripheral wall and the inner peripheral wall, extending from a first end face to a second end face and defining a plurality of cells that serve as flow paths for a first fluid, In a cross section of the honeycomb structure perpendicular to a flow path direction of the first fluid, the partition walls include a plurality of first partition walls extending in a radial direction and a plurality of second partition walls extending in a circumferential direction, The number of the cells closest to the outer peripheral wall in the circumferential direction is greater than the number of the cells closest to the inner peripheral wall in the circumferential direction. Ku, the partition walls include the first partition walls having portions adjacent to each other in the circumferential direction that have different thicknesses; It is a heat conductive member. The present invention also provides a heat conduction member including a honeycomb structure having an outer peripheral wall, an inner peripheral wall, and partition walls disposed between the outer peripheral wall and the inner peripheral wall, extending from a first end face to a second end face and defining a plurality of cells that serve as flow paths for a first fluid, In a cross section of the honeycomb structure perpendicular to a flow path direction of the first fluid, the partition walls include a plurality of first partition walls extending in a radial direction and a plurality of second partition walls extending in a circumferential direction, the number of the cells in the circumferential direction closest to the outer circumferential wall is greater than the number of the cells in the circumferential direction closest to the inner circumferential wall, The honeycomb structure is a heat conduction member having two or more regions including the first partition walls whose thicknesses differ in the circumferential direction.

[0011] Furthermore, the present invention provides a heat conductive member, an outer cylinder arranged radially outward from the covering member at a distance so that a second fluid can flow around the outer periphery of the covering member; It is a heat exchanger comprising: [Effects of the Invention]

[0012] According to the present invention, it is possible to provide a heat transfer member and a heat exchanger that can improve heat recovery efficiency. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is a cross-sectional view of a heat conduction member according to a first embodiment of the present invention, taken along a line parallel to the axial direction of a honeycomb structure. [Figure 2] 2 is a cross-sectional view of the heat conducting member taken along line aa' in FIG. [Figure 3] FIG. 4 is a cross-sectional view perpendicular to the axial direction of the honeycomb structure of a heat conduction member in another aspect according to the first embodiment of the present invention. [Figure 4]FIG. 4 is a cross-sectional view perpendicular to the axial direction of the honeycomb structure of a heat conduction member in another aspect according to the first embodiment of the present invention. [Figure 5] FIG. 4 is a cross-sectional view perpendicular to the axial direction of the honeycomb structure of a heat conduction member in another aspect according to the first embodiment of the present invention. [Figure 6] FIG. 4 is a cross-sectional view perpendicular to the axial direction of the honeycomb structure of a heat conduction member in another aspect according to the first embodiment of the present invention. [Figure 7] FIG. 4 is a cross-sectional view perpendicular to the axial direction of the honeycomb structure of a heat conduction member in another aspect according to the first embodiment of the present invention. [Figure 8] 1 is a cross-sectional view of a heat exchanger according to a first embodiment of the present invention, taken along a line parallel to the axial direction of a honeycomb structure. [Figure 9] 9 is a cross-sectional view of the heat exchanger shown in FIG. 8 taken along line bb'. [Figure 10] FIG. 4 is a cross-sectional view of a heat conduction member according to a second embodiment of the present invention, taken along a line parallel to the axial direction of a honeycomb structure. [Figure 11] 11 is a cross-sectional view of the heat conducting member shown in FIG. 10 taken along the line cc'. FIG. [Figure 12] FIG. 10 is a cross-sectional view perpendicular to the axial direction of the honeycomb structure of another aspect of the heat conduction member according to the second embodiment of the present invention. [Figure 13] FIG. 10 is a cross-sectional view perpendicular to the axial direction of the honeycomb structure of another aspect of the heat conduction member according to the second embodiment of the present invention. [Figure 14] 1 is an enlarged partial cross-sectional view perpendicular to the axial direction of the honeycomb structure produced in Example 1. FIG. [Figure 15] 1 is an enlarged partial cross-sectional view perpendicular to the axial direction of the honeycomb structure produced in Example 2. FIG. [Figure 16] 1 is an enlarged partial cross-sectional view perpendicular to the axial direction of the honeycomb structure produced in Comparative Example 1. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0014] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The present invention is not limited to the following embodiments, and it should be understood that modifications and improvements made to the following embodiments based on the ordinary knowledge of those skilled in the art without departing from the spirit of the present invention are also within the scope of the present invention.

[0015] <Embodiment 1> (1) Heat conductive material Fig. 1 is a cross-sectional view of the heat conduction member according to the first embodiment of the present invention, taken along the line parallel to the axial direction of the honeycomb structure (the flow path direction of the first fluid). Fig. 2 is a cross-sectional view of the heat conduction member shown in Fig. 1 taken along the line a-a', i.e., a cross-sectional view of the heat conduction member according to the first embodiment of the present invention, taken along the line perpendicular to the axial direction of the honeycomb structure.

[0016] A heat conduction member 100 according to a first embodiment of the present invention includes a honeycomb structure 10 having an outer peripheral wall 11 and a plurality of partition walls 15 disposed inside the outer peripheral wall 11 and extending from a first end face 12 to a second end face 13 to define a plurality of cells 14 that serve as flow paths for a first fluid. The heat conduction member 100 may also include a covering member 20 that covers the outer peripheral surface of the outer peripheral wall 11, as necessary. In the heat conduction member 100 having such a structure, heat exchange between the first fluid capable of flowing inside the cells 14 and the second fluid capable of flowing around the periphery of the outer wall 11 occurs via the outer wall 11 of the honeycomb structure 10. Furthermore, when the heat conduction member 100 includes a covering member 20, heat exchange between the first fluid capable of flowing inside the cells 14 and the second fluid capable of flowing around the periphery of the covering member 20 occurs via the outer wall 11 and the covering member 20. 1, the first fluid can flow in either the left or right direction on the paper. The first fluid is not particularly limited, and various liquids or gases can be used. For example, when the heat conducting member 100 is used in a heat exchanger mounted on an automobile, the first fluid is preferably exhaust gas.

[0017] The partition walls 15 constituting the honeycomb structure 10 include a plurality of first partition walls 15a extending in the radial direction and a plurality of second partition walls 15b extending in the circumferential direction in a cross section of the honeycomb structure 10 perpendicular to the flow direction of the first fluid (i.e., the cross section shown in FIG. 2). By using partition walls 15 (particularly, first partition walls 15a) with such a structure, the heat of the first fluid can be transferred in the radial direction via the first partition walls 15a, and therefore the heat of the first fluid can be transferred efficiently to the outside of the honeycomb structure 10.

[0018] In at least a portion of the first partition walls 15a, the thickness of a portion defining the cells 14 closest to the peripheral wall 11 is greater than the thickness of a portion defining the cells 14 closest to the center. For example, in the honeycomb structure 10 shown in FIG. 2, the thickness of portion A defining the cells 14 closest to the peripheral wall 11 is greater than the thickness of portion D defining the cells 14 closest to the center. By using the first partition walls 15a with such a structure, the difference between the cell width on the center side and the cell width on the peripheral wall 11 side can be reduced. As a result, the cells 14 on the peripheral wall 11 side can recover heat to the same extent as the cells 14 on the center side, thereby improving the heat recovery efficiency of the honeycomb structure 10 as a whole. Furthermore, because the thickness of the portion defining the cells 14 closest to the peripheral wall 11 is greater, damage (e.g., cracks, fractures, etc.) of the honeycomb structure 10 due to external impacts, thermal stress due to the temperature difference between the first and second fluids, etc. can be suppressed. Here, in this specification, "cell width" means the linear length at the radial center between two first partitions 15a that constitute one cell 14 (i.e., the linear length connecting the radial centers of two first partitions 15a that constitute one cell 14). In Figure 2, an example is shown in which, in all of the first partition walls 15a, the thickness of portion A that defines the cells 14 closest to the outer peripheral wall 11 is greater than the thickness of portion D that defines the cells 14 closest to the center. However, it should be noted that a portion of the first partition walls 15a may have the same thickness from the center to the outer peripheral wall 11.

[0019] At least a portion of the first partition walls 15a has three or more portions that define three or more cells 14 in the radial direction, and the thickness of the portion that defines the cells 14 located on the outer peripheral wall 11 side may be the same as or greater than the thickness of the portion that defines the cells 14 located on the central side. For example, the honeycomb structure 10 shown in FIG. 2 has four portions A to D that define four cells 14 in the radial direction, and the thickness of portion A is greater than the thickness of portions B to D, and portions B to D have the same thickness. By using the first partition walls 15a with such a structure, it is possible to easily reduce the difference in cell width between the central side and the outer peripheral wall 11 side, thereby improving the heat recovery efficiency of the cells 14 on the outer peripheral wall 11 side. 2 shows an example in which the thicknesses of the portions B to D are all the same, it should be noted that the thicknesses of the portions B to D may be different. For example, the thickness of the portion B may be greater than the thicknesses of the portions C and D, and the thickness of the portion C may be greater than the thickness of the portion D.

[0020] The thickness of the first partition walls 15a may gradually increase from the center toward the outer peripheral wall 11. A cross-sectional view of a heat conduction member having such a structure, taken perpendicular to the axial direction of the honeycomb structure, is shown in Fig. 3. Even in the heat conduction member 200 including the honeycomb structure 10 having the first partition walls 15a with such a structure, the difference between the cell width on the center side and the cell width on the outer peripheral wall 11 side can be easily reduced, thereby improving the heat recovery efficiency in the cells 14 on the outer peripheral wall 11 side. Although Figure 3 shows an example in which the thickness of all of the first partition walls 15a gradually increases from the center toward the outer peripheral wall 11, it should be noted that the thickness of some of the first partition walls 15a may gradually increase from the center toward the outer peripheral wall 11.

[0021] 2 and 3, the first partition walls 15a may extend in a straight line from the center toward the outer peripheral wall 11. By using first partition walls 15a with such a structure, the heat transfer path of the first partition walls 15a is straight, and therefore the heat of the first fluid can be efficiently transferred to the outside of the honeycomb structure 10. On the other hand, if the first partition walls 15a do not extend in a straight line from the center toward the outer peripheral wall 11, the heat transfer path of the first partition walls 15a is curved (heat transfer becomes necessary via the second partition walls 15b), and therefore it becomes difficult to efficiently transfer the heat of the first fluid to the outside of the honeycomb structure 10.

[0022] The partition walls 15 may include first partition walls 15a in which adjacent portions in the circumferential direction have different thicknesses. A cross-sectional view perpendicular to the axial direction of the honeycomb structure of a heat conduction member having such a structure is shown in Fig. 4. Even in a heat conduction member 300 including a honeycomb structure 10 having first partition walls 15a with such a structure, the difference between the cell width on the central side and the cell width on the outer peripheral wall 11 side can be easily reduced, thereby improving the heat recovery efficiency in the cells 14 on the outer peripheral wall 11 side.

[0023] The honeycomb structure 10 may have two or more regions including first partition walls 15a with different thicknesses in the circumferential direction. FIG. 5 shows a cross-sectional view of a heat conduction member having such a structure, taken perpendicular to the axial direction of the honeycomb structure. The honeycomb structure 10 in the heat conduction member 400 shown in FIG. 5 has two regions r1 and r2 including first partition walls 15a with different thicknesses in the circumferential direction. In an actual heat exchanger, depending on the position of the supply or discharge port for the second fluid flowing around the outer periphery of the outer peripheral wall 11 (or the covering member 20, if present), there may be regions in the circumferential direction of the honeycomb structure where the heat of the first fluid is easily recovered and regions where the heat of the first fluid is difficult to recover. Therefore, by providing the region r1 including thick first partition walls 15a in the region where the heat of the first fluid is easily recovered and the region r2 including thin first partition walls 15a in the region where the heat of the first fluid is difficult to recover, the heat of the first fluid can be efficiently recovered.

[0024] In the honeycomb structure 10, among the cells 14 defined by the first partition walls 15a, the number of cells 14 closest to the outer peripheral wall 11 in the circumferential direction may be greater than the number of cells 14 closest to the center in the circumferential direction. FIG. 6 shows a cross-sectional view of a heat conduction member having such a structure, taken perpendicular to the axial direction of the honeycomb structure. In the honeycomb structure 10 of the heat conduction member 500 shown in FIG. 6, among the cells 14 defined by the first partition walls 15a, the number of cells 14 closest to the outer peripheral wall 11 in the circumferential direction is 16, while the number of cells 14 closest to the center in the circumferential direction is 8. By controlling the number of cells 14 in the circumferential direction in this manner, it is possible to easily reduce the difference in cell width between the center side and the outer peripheral wall 11 side, thereby improving the heat recovery efficiency of the cells 14 on the outer peripheral wall 11 side.

[0025] At least a portion of the first partition walls 15a has three or more portions that define three or more cells 14 in the radial direction, and the number of cells 14 located on the outer peripheral wall 11 side in the circumferential direction may be equal to or greater than the number of cells 14 located on the central side in the circumferential direction. For example, in the honeycomb structure 10 shown in FIG. 6, the first partition walls 15a have four portions A to D that define four cells 14 in the radial direction, and the number of cells 14 defined in the circumferential direction by partition walls 15 including portion A is the same as the number of cells 14 defined in the circumferential direction by partition walls 15 including portion B or C and is greater than the number of cells 14 defined in the circumferential direction by partition walls 15 including portion D. Furthermore, the number of cells 14 defined in the circumferential direction by partition walls 15 including portion B is the same as the number of cells 14 defined in the circumferential direction by partition walls 15 including portion C and is greater than the number of cells 14 defined in the circumferential direction by partition walls 15 including portion D. Furthermore, the number of cells 14 in the circumferential direction that are defined by partition walls 15 including portion C is greater than the number of cells 14 in the circumferential direction that are defined by partition walls 15 that include portion D. By controlling the number of cells 14 in the circumferential direction in this manner, it is possible to easily reduce the difference in cell width between the central side and the outer peripheral wall 11 side, thereby improving the heat recovery efficiency of cells 14 on the outer peripheral wall 11 side.

[0026] The cells 14 defined by the first partition wall 15a and the second partition wall 15b preferably have substantially the same cell width in the circumferential direction. With this configuration, the flow path resistance in the circumferential direction becomes the same, and the first fluid can flow uniformly in the circumferential direction.

[0027] The shape (external shape) of the honeycomb structure 10 is not particularly limited and may be, for example, a circular cylinder, an elliptical cylinder, a square cylinder, or other polygonal cylinders. Note that Figures 1 to 6 show an example in which the shape (external shape) of the honeycomb structure 10 is a cylinder.

[0028] The honeycomb structure 10 is not limited to the solid honeycomb structure shown in Figs. 1 to 6, and may be a hollow honeycomb structure having a hollow region in the center, into which a tubular member can be inserted, in a cross section perpendicular to the axial direction of the honeycomb structure 10. Fig. 7 shows a cross section perpendicular to the axial direction of a heat conduction member having such a structure. The honeycomb structure 10 in the heat conduction member 600 shown in Fig. 7 further includes an inner peripheral wall 16, and partition walls 15 (first partition wall 15a and second partition wall 15b) are disposed between the outer peripheral wall 11 and the inner peripheral wall 16. Even with such a hollow honeycomb structure, it is possible to obtain the same effects as those of the solid honeycomb structure described above. In the hollow honeycomb structure, the outer shape and the shape of the hollow region may be the same or different, but it is preferable that they are the same from the viewpoint of resistance to external impacts, thermal stress, and the like.

[0029] The thickness of the outer peripheral wall 11 (in the case of a hollow honeycomb structure, the outer peripheral wall 11 and the inner peripheral wall 16) and the partition walls 15 (the first partition walls 15a and the second partition walls 15b) can be adjusted appropriately depending on the application. The thickness of the outer peripheral wall 11 (in the case of a hollow honeycomb structure, the outer peripheral wall 11 and the inner peripheral wall 16) is preferably greater than the thickness of the second partition walls 15b. By adopting such a configuration, it is possible to increase the strength of the outer peripheral wall 11 (in the case of a hollow honeycomb structure, the outer peripheral wall 11 and the inner peripheral wall 16), which is prone to destruction (for example, cracks, breakage, etc.) due to external impacts, thermal stress caused by the temperature difference between the first fluid and the second fluid, etc.

[0030] When the heat conduction members 100, 200, 300, 400, 500, and 600 are used for general heat exchange purposes, the thickness of the outer peripheral wall 11 and the inner peripheral wall 16 is preferably more than 0.3 mm and not more than 10 mm, more preferably 0.5 mm to 5 mm, and even more preferably 1 mm to 3 mm. Furthermore, when the heat conduction members 100, 200, 300, 400, 500, and 600 are used for heat storage purposes, it is also preferable that the thickness of the outer peripheral wall 11 be 10 mm or more to increase the heat capacity of the outer peripheral wall 11. The thickness of the first partition walls 15a at the portions defining the cells 14 closest to the outer peripheral wall 11 is preferably 0.05 to 1 mm, more preferably 0.1 to 0.8 mm, and even more preferably 0.2 to 0.6 mm. The thickness of the first partition walls 15a at the portions defining the cells 14 closest to the center is preferably 0.02 to 0.9 mm, more preferably 0.05 to 0.7 mm, and even more preferably 0.1 to 0.5 mm. The thickness of the second partition walls 15b is preferably 0.1 to 1 mm, and more preferably 0.2 to 0.6 mm. By making the thickness of the second partition walls 15b 0.1 mm or more, it is possible to ensure sufficient mechanical strength of the honeycomb structure 10. Furthermore, by making the thickness of the second partition walls 15b 1 mm or less, it is possible to suppress problems such as an increase in pressure loss due to a decrease in the opening area and a decrease in heat recovery efficiency due to a decrease in the contact area with the first fluid.

[0031] The outer peripheral wall 11 (in the case of a hollow honeycomb structure, the outer peripheral wall 11 and the inner peripheral wall 16) and the partition walls 15 are mainly composed of ceramics. "Mainly composed of ceramics" means that the mass ratio of ceramics to the total mass is 50 mass% or more.

[0032] The porosity of the outer peripheral wall 11 (in the case of a hollow honeycomb structure, the outer peripheral wall 11 and the inner peripheral wall 16) and the partition walls 15 is preferably 10% or less, more preferably 5% or less, and even more preferably 3% or less. The porosity of the outer peripheral wall 11, the inner peripheral wall 16 and the partition walls 15 can also be 0%. By setting the porosity of the outer peripheral wall 11, the inner peripheral wall 16 and the partition walls 15 to 10% or less, the thermal conductivity can be improved.

[0033] The outer peripheral wall 11 (in the case of a hollow honeycomb structure, the outer peripheral wall 11 and the inner peripheral wall 16) and the partition walls 15 preferably contain SiC (silicon carbide), which has high thermal conductivity, as a main component. "Containing SiC (silicon carbide) as a main component" means that the mass ratio of SiC (silicon carbide) to the total mass is 50 mass% or more. Specifically, Si-SiC-based materials such as Si-impregnated SiC and (Si+Al)-impregnated SiC, metal composite SiC, recrystallized SiC, Si3N4, and SiC can be used as materials for the outer peripheral wall 11, the inner peripheral wall 16, and the partition walls 15. Among these, it is preferable to use Si-SiC-based materials because they can be manufactured inexpensively and have high thermal conductivity.

[0034] The cell density (i.e., the number of cells 14 per unit area) in a cross section perpendicular to the axial direction of the honeycomb structure 10 is not particularly limited and may be adjusted appropriately depending on the application, etc., but is preferably 4 to 320 cells / cm. 2 The cell density is preferably in the range of 4 cells / cm. 2 By setting the cell density to the above, it is possible to sufficiently secure the strength of the partition walls 15, and in turn the strength and effective GSA (geometric surface area) of the honeycomb structure 10 itself. 2 By setting the above, it is possible to prevent an increase in pressure loss when the first fluid flows.

[0035] The isostatic strength of the honeycomb structure 10 is preferably more than 100 MPa, more preferably 150 MPa or more, and even more preferably 200 MPa or more. When the isostatic strength of the honeycomb structure 10 exceeds 100 MPa, the honeycomb structure 10 has excellent durability. The isostatic strength of the honeycomb structure 10 can be measured in accordance with the method for measuring isostatic fracture strength specified in JASO standard M505-87, an automotive standard issued by the Society of Automotive Engineers of Japan.

[0036] The diameter (outer diameter) of the outer peripheral wall 11 in a cross section perpendicular to the axial direction of the honeycomb structure 10 is preferably 20 to 200 mm, more preferably 30 to 100 mm. By setting the diameter in this range, it is possible to improve the heat recovery efficiency. When the outer peripheral wall 11 is not circular, the diameter of the outer peripheral wall 11 is defined as the diameter of the largest inscribed circle inscribed in the cross-sectional shape of the outer peripheral wall 11. Furthermore, when the honeycomb structure 10 is a hollow honeycomb structure, the diameter of the inner peripheral wall 16 in a cross section perpendicular to the axial direction of the honeycomb structure 10 is preferably 1 to 50 mm, and more preferably 2 to 30 mm. When the cross-sectional shape of the inner peripheral wall 16 is not circular, the diameter of the inner peripheral wall 16 is defined as the diameter of the largest inscribed circle inscribed in the cross-sectional shape of the inner peripheral wall 16.

[0037] The thermal conductivity of the honeycomb structure 10 at 25°C is preferably 50 W / (m·K) or more, more preferably 100 to 300 W / (m·K), and even more preferably 120 to 300 W / (m·K). By setting the thermal conductivity of the honeycomb structure 10 within this range, the thermal conductivity is improved, and heat within the honeycomb structure 10 can be efficiently transferred to the outside. The thermal conductivity value is measured by a laser flash method (JIS R1611:1997).

[0038] When exhaust gas is flowed as the first fluid through the cells 14 of the honeycomb structure 10, it is preferable to support a catalyst on the partition walls 15 of the honeycomb structure 10. Supporting a catalyst on the partition walls 15 makes it possible to convert CO, NOx, HC, and other substances in the exhaust gas into harmless substances through a catalytic reaction, and also makes it possible to use the reaction heat generated during the catalytic reaction for heat exchange. The catalyst preferably contains at least one element selected from the group consisting of 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 barium. The above elements may be contained as simple metals, metal oxides, or other metal compounds.

[0039] The amount of catalyst (catalytic metal + support) supported is preferably 10 to 400 g / L. Furthermore, if the catalyst contains a precious metal, the amount supported is preferably 0.1 to 5 g / L. When the amount of catalyst (catalytic metal + support) supported is 10 g / L or more, catalytic action is easily exhibited. On the other hand, when it is 400 g / L or less, pressure loss and an increase in production costs can be suppressed. The support is a carrier on which the catalytic metal is supported. The support preferably contains at least one selected from the group consisting of alumina, ceria, and zirconia.

[0040] The covering member 20 is not particularly limited as long as it can cover the outer peripheral surface of the outer peripheral wall 11 of the honeycomb structure 10. For example, a tubular member can be used that fits onto the outer peripheral surface of the outer peripheral wall 11 of the honeycomb structure 10 and covers the outer peripheral wall 11 of the honeycomb structure 10. Furthermore, from the viewpoint of buffering action, an inorganic mat or the like may be interposed between the honeycomb structure 10 and the covering member 20. Here, in this specification, "fitting" means that the honeycomb structure 10 and the covering member 20 are fixed in a fitted state to each other. Therefore, the fitting of the honeycomb structure 10 and the covering member 20 includes fixing methods using fitting such as clearance fitting, interference fitting, and shrink fitting, as well as cases where the honeycomb structure 10 and the covering member 20 are fixed to each other by brazing, welding, diffusion bonding, etc.

[0041] The covering member 20 can have an inner surface shape corresponding to the outer wall 11 of the honeycomb structure 10. When the inner surface of the covering member 20 is in direct contact with the outer wall 11 of the honeycomb structure 10, the thermal conductivity is improved and the heat inside the honeycomb structure 10 can be efficiently transferred to the covering member 20.

[0042] From the viewpoint of improving heat recovery efficiency, it is preferable that the ratio of the area of ​​the outer peripheral surface of the outer peripheral wall 11 of the honeycomb structure 10 that is circumferentially covered by the covering member 20 to the total area of ​​the outer peripheral surface of the outer peripheral wall 11 of the honeycomb structure 10 is high. Specifically, the area ratio is preferably 80% or more, more preferably 90% or more, and even more preferably 100% (i.e., the entire outer peripheral surface of the outer peripheral wall 11 of the honeycomb structure 10 is circumferentially covered by the covering member 20). The "peripheral wall 11" here refers to a surface parallel to the axial direction of the honeycomb structure 10, and does not include surfaces perpendicular to the axial direction of the honeycomb structure 10 (first end face 12 and second end face 13).

[0043] The covering member 20 is preferably made of metal from the viewpoint of manufacturability. Furthermore, if the covering member 20 is made of metal, it is advantageous in that it can be easily welded to the outer cylinder 30 (casing), which will be described later. Examples of materials that can be used for the covering member 20 include stainless steel, titanium alloys, copper alloys, aluminum alloys, and brass. Among these, stainless steel is preferred because of its high durability, reliability, and low cost.

[0044] The thickness of the covering member 20 is preferably 0.1 mm or more, more preferably 0.3 mm or more, and even more preferably 0.5 mm or more, for reasons of durability and reliability. The thickness of the covering member 20 is preferably 10 mm or less, more preferably 5 mm or less, and even more preferably 3 mm or less, for reasons of reducing thermal resistance and increasing thermal conductivity.

[0045] The length of the covering member 20 (length in the flow path direction of the first fluid) is not particularly limited and may be adjusted appropriately depending on the size of the honeycomb structure 10. For example, the length of the covering member 20 is preferably greater than the length of the honeycomb structure 10. Specifically, the length of the covering member 20 is preferably 5 mm to 250 mm, more preferably 10 mm to 150 mm, and even more preferably 20 mm to 100 mm. When the length of the covering member 20 is greater than the length of the honeycomb structure 10 , it is preferable that the covering member 20 is provided so that the honeycomb structure 10 is positioned at the center of the covering member 20 .

[0046] Next, a description will be given of a method for manufacturing the heat conduction members 100, 200, 300, 400, 500, and 600. However, the method for manufacturing the heat conduction members 100, 200, 300, 400, 500, and 600 is not limited to the manufacturing method described below. First, a clay containing ceramic powder is extruded into a desired shape to produce a honeycomb molded body. At this time, by selecting an appropriate die and jig, the shape and density of the cells 14, the number, length, and thickness of the partition walls 15 (first partition walls 15a and second partition walls 15b), and the shapes and thicknesses of the outer peripheral wall 11 and inner peripheral wall 16 can be controlled. The above-mentioned ceramics can also be used as the material for the honeycomb molded body. For example, when manufacturing a honeycomb molded body primarily composed of a Si-impregnated SiC composite material, a predetermined amount of SiC powder is mixed with a binder and water or an organic solvent, and the resulting mixture is kneaded to form a clay, which is then molded to produce a honeycomb molded body of the desired shape. The resulting honeycomb molded body is then dried and impregnated with metal Si in a reduced-pressure inert gas or vacuum, followed by firing, to produce a honeycomb structure 10.

[0047] Next, the honeycomb structure 10 is shrink-fitted into the covering member 20, thereby covering the outer peripheral surface of the outer wall 11 of the honeycomb structure 10 with the covering member 20. Specifically, the covering member 20 is heated and expanded, the honeycomb structure 10 is inserted into the covering member 20, and then the covering member 20 is cooled and contracted, thereby fixing the honeycomb structure 10 in the covering member 20. Note that the fitting of the honeycomb structure 10 and the covering member 20 can be performed by a fixing method based on fitting, such as a clearance fit or an interference fit, as well as shrink fitting, as described above, or by brazing, welding, diffusion bonding, or the like. In this manner, the heat conduction member 100 can be obtained.

[0048] The heat conduction members 100, 200, 300, 400, 500, and 600 according to embodiment 1 of the present invention include a honeycomb structure 10 having a first partition wall 15a in which the thickness of the portion defining the cells 14 closest to the outer wall 11 is greater than the thickness of the portion defining the cells 14 closest to the center. Therefore, the difference between the cell width on the center side and the cell width on the outer wall 11 side is small, and heat recovery can be performed in the cells 14 on the outer wall 11 side to the same extent as in the cells 14 on the center side.

[0049] (2) Heat exchanger The heat exchanger according to the first embodiment of the present invention includes the above-described heat conduction members 100, 200, 300, 400, 500, and 600. The components other than the heat conduction members 100, 200, 300, 400, 500, and 600 are not particularly limited, and known components can be used. For example, the heat exchanger according to the first embodiment of the present invention may include the heat conduction members 100, 200, 300, 400, 500, and 600, and an outer cylinder (casing) disposed radially outward from and spaced apart from the covering member 20 of the heat conduction members 100, 200, 300, 400, 500, and 600 so that the second fluid can flow around the outer periphery of the covering member 20.

[0050] Fig. 8 is a cross-sectional view parallel to the axial direction of the honeycomb structure of the heat exchanger according to the first embodiment of the present invention. Fig. 9 is a cross-sectional view taken along line b-b' of the heat exchanger shown in Fig. 8, which is a cross-sectional view perpendicular to the axial direction of the honeycomb structure of the heat exchanger according to the first embodiment of the present invention.

[0051] A heat exchanger 1000 according to a first embodiment of the present invention includes a heat conduction member 100 and an outer cylinder 30 disposed radially outward from and spaced apart from the covering member 20 so that a second fluid can flow around the outer periphery of the covering member 20 of the heat conduction member 100. The outer cylinder 30 has a supply pipe 31 and a discharge pipe 32 for the second fluid. Preferably, the outer cylinder 30 covers the entire outer periphery of the heat conduction member 100. In the heat exchanger 1000 having the above-described structure, the second fluid flows into the outer casing 30 from the supply pipe 31. Next, while passing through the second fluid flow path, the second fluid exchanges heat with the first fluid flowing through the cells 14 of the honeycomb structure 10 via the covering member 20 of the heat conduction member 100, and is then discharged from the second fluid discharge pipe 32. The outer peripheral surface of the covering member 20 of the heat conduction member 100 may be covered with a member for adjusting heat transfer efficiency.

[0052] The second fluid is not particularly limited, but when the heat exchanger 1000 is installed in an automobile, the second fluid is preferably water or antifreeze (LLC as defined in JIS K2234:2006). Regarding the temperatures of the first and second fluids, it is preferable that the temperature of the first fluid is greater than the temperature of the second fluid. This is because the covering member 20 of the heat conduction member 100 does not expand at low temperatures, and the honeycomb structure 10 expands at higher temperatures, making it difficult for the fitting between the two to loosen. In particular, when the fitting between the honeycomb structure 10 and the covering member 20 is shrink-fitted, the risk of the fitting loosening and the honeycomb structure 10 falling off can be minimized.

[0053] The inner surface of the outer cylinder 30 is preferably fitted with the outer peripheral surface of the covering member 20 of the heat conduction member 100. In this way, the outer peripheral surfaces of the covering member 20 at both ends in the flow path direction of the first fluid are in close circumferential contact with the inner surface of the outer cylinder 30, making it possible to prevent leakage of the second fluid to the outside. Methods for bringing the outer peripheral surface of the covering member 20 into close contact with the inner surface of the outer cylinder 30 include, but are not limited to, welding, diffusion bonding, brazing, mechanical fastening, and the like. Among these, welding is preferred because it has high durability and reliability and can also improve structural strength.

[0054] From the viewpoints of thermal conductivity and manufacturability, the outer cylinder 30 is preferably made of a metal. Examples of metals that can be used include stainless steel, titanium alloys, copper alloys, aluminum alloys, and brass. Among these, stainless steel is preferred because it is inexpensive and has high durability and reliability.

[0055] For reasons of durability and reliability, the thickness of the outer cylinder 30 is preferably 0.1 mm or more, more preferably 0.5 mm or more, and even more preferably 1 mm or more. From the viewpoints of cost, volume, weight, etc., the thickness of the outer cylinder 30 is preferably 10 mm or less, more preferably 5 mm or less, and even more preferably 3 mm or less.

[0056] The outer cylinder 30 may be an integrally molded product, or may be a joined member formed from two or more members. When the outer cylinder 30 is a joined member formed from two or more members, the degree of freedom in designing the outer cylinder 30 can be increased.

[0057] The positions of the supply pipe 31 and the discharge pipe 32 for the second fluid are not particularly limited, and can be appropriately changed in the axial and circumferential directions in consideration of the installation location of the heat exchanger 1000, the piping position, the heat exchange efficiency, etc. For example, the supply pipe 31 and the discharge pipe 32 for the second fluid can be provided at positions corresponding to both axial ends of the honeycomb structure 10. Furthermore, the supply pipe 31 and the discharge pipe 32 for the second fluid may extend in the same direction or in different directions.

[0058] 8 and 9 show the case where the heat conducting member 100 is used, but the heat conducting member 200, 300, 400, 500, or 600 may be used instead of the heat conducting member 100. When the heat conducting member 600 is used, an inner cylinder may be further provided in the hollow region of the honeycomb structure 10 (on the inner periphery side of the inner periphery wall 16) and an on-off valve may be provided in the inner cylinder. The inner tube may have through holes formed therein for introducing the first fluid into the cells 14 of the honeycomb structure 10, and the through holes may branch the flow of the first fluid into two (the cells 14 of the honeycomb structure 10 and the hollow portion). The on-off valve can use its on-off mechanism to control the amount of the first fluid flowing through the hollow region of the honeycomb structure 10. In particular, the on-off valve can selectively introduce the first fluid into the cells 14 of the honeycomb structure 10 through the through holes by blocking the flow of the first fluid inside the inner cylinder during heat exchange between the first fluid and the second fluid, thereby enabling efficient heat exchange between the first fluid and the second fluid.

[0059] The through-holes provided in the inner cylinder may be formed around the entire circumference of the inner cylinder, or may be formed in a partial position of the inner cylinder (for example, only the upper, central, or lower part). The shape of the through-holes may be various shapes such as circular, elliptical, or rectangular.

[0060] In the heat exchanger 1000 having such a structure, the first fluid can be circulated inside the inner cylinder. When the on-off valve is closed, the airflow resistance inside the inner cylinder increases, and the first fluid selectively flows into the cells 14 through the through-holes. On the other hand, when the on-off valve is open, the airflow resistance inside the inner cylinder decreases, and the first fluid selectively flows into the inner cylinder in the hollow region. Therefore, by controlling the opening and closing of the on-off valve, the amount of the first fluid flowing into the cells 14 can be adjusted. Note that the first fluid flowing through the inner cylinder in the hollow region hardly contributes to heat exchange with the second fluid, and therefore the path of this first fluid functions as a bypass path when it is desired to suppress the heat recovery of the first fluid. In other words, when it is desired to suppress the heat recovery of the first fluid, the on-off valve can be opened.

[0061] Next, a description will be given of a method for manufacturing the heat exchanger 1000. However, the method for manufacturing the heat exchanger 1000 is not limited to the manufacturing method described below. The heat exchanger 1000 can be manufactured by placing and joining the outer casing 30 radially outward of the covering member 20 of the heat conduction members 100, 200, 300, 400, 500, and 600 at a distance so that the second fluid can flow around the outer periphery of the covering member 20. Specifically, both ends of the covering member 20 of the heat conduction members 100, 200, 300, 400, 500, and 600 are joined to the inner surface of the outer casing 30. As described above, various joining methods, including fitting, are available. If necessary, the joining points can be joined by welding or other methods. This forms the outer casing 30 that surrounds and covers the outer periphery of the covering member 20, and a flow path for the second fluid is formed between the outer periphery of the covering member 20 and the inner surface of the outer casing 30. In this manner, the heat exchanger 1000 can be obtained. Furthermore, when an inner cylinder and an on-off valve are further provided, the inner cylinder provided with the on-off valve may be inserted into the inner peripheral wall 16 of the honeycomb structure 10 and fitted by shrink fitting. As described above, the fitting between the inner peripheral wall 16 of the honeycomb structure 10 and the inner cylinder may be performed by a fixing method based on fitting such as a clearance fit or an interference fit, as well as by shrink fitting, brazing, welding, diffusion bonding, or the like.

[0062] The heat exchanger 1000 according to the first embodiment of the present invention includes the above-described heat conduction members 100, 200, 300, 400, 500, and 600, and therefore can improve heat recovery efficiency.

[0063] <Embodiment 2> (1) Heat conductive material Fig. 10 is a cross-sectional view of the heat conduction member according to the second embodiment of the present invention, taken parallel to the axial direction of the honeycomb structure (the flow path direction of the first fluid). Fig. 11 is a cross-sectional view of the heat conduction member shown in Fig. 10 taken along line c-c', i.e., a cross-sectional view of the heat conduction member according to the second embodiment of the present invention, taken perpendicular to the axial direction of the honeycomb structure. 10 and 11, components denoted by the same reference numerals as those in the above figures indicate the same components, and detailed description thereof will be omitted.

[0064] A heat conduction member 700 according to a second embodiment of the present invention includes a honeycomb structure 10 having an outer peripheral wall 11, an inner peripheral wall 16, and partition walls 15 disposed between the outer peripheral wall 11 and the inner peripheral wall 16, extending from a first end face 12 to a second end face 13 and defining a plurality of cells 14 that serve as flow paths for a first fluid. The heat conduction member 700 may also include a covering member 20 that covers the outer peripheral surface of the outer peripheral wall 11, as necessary. In the heat conduction member 700 having such a structure, heat exchange between the first fluid capable of flowing inside the cells 14 and the second fluid capable of flowing around the periphery of the outer wall 11 occurs via the outer wall 11 of the honeycomb structure 10. Furthermore, when the heat conduction member 700 includes the covering member 20, heat exchange between the first fluid capable of flowing inside the cells 14 and the second fluid capable of flowing around the periphery of the covering member 20 occurs via the outer wall 11 and the covering member 20.

[0065] The partition walls 15 constituting the honeycomb structure 10 include a plurality of first partition walls 15a extending in the radial direction and a plurality of second partition walls 15b extending in the circumferential direction in a cross section of the honeycomb structure 10 perpendicular to the flow direction of the first fluid (i.e., the cross section shown in FIG. 11). By using partition walls 15 (particularly, first partition walls 15a) with such a structure, the heat of the first fluid can be transferred in the radial direction via the first partition walls 15a, and therefore the heat of the first fluid can be transferred efficiently to the outside of the honeycomb structure 10.

[0066] In the honeycomb structure 10, the number of cells 14 closest to the outer peripheral wall 11 in the circumferential direction is greater than the number of cells 14 closest to the inner peripheral wall 16 in the circumferential direction. For example, in the honeycomb structure 10 of the heat conduction member 700 shown in FIG. 11, the number of cells 14 closest to the outer peripheral wall 11 in the circumferential direction is 32, while the number of cells 14 closest to the inner peripheral wall 16 in the circumferential direction is 16. By controlling the number of cells 14 in the circumferential direction in this manner, the difference between the cell width on the inner peripheral wall 16 side and the cell width on the outer peripheral wall 11 side can be reduced. As a result, the cells 14 on the outer peripheral wall 11 side can also recover heat to the same extent as the cells 14 on the inner peripheral wall 16 side, thereby improving the heat recovery efficiency of the honeycomb structure 10 as a whole.

[0067] The first partition walls 15a have three or more portions that define three or more cells 14 in the radial direction, and the number of cells 14 located on the outer peripheral wall 11 side in the circumferential direction may be equal to or greater than the number of cells 14 located on the inner peripheral wall 16 side in the circumferential direction. For example, in the honeycomb structure 10 shown in FIG. 11 , the first partition walls 15a have three portions O to Q that define three cells 14 in the radial direction, and the number of cells 14 defined in the circumferential direction by the partition walls 15 including portion O is greater than the number of cells 14 defined in the circumferential direction by the partition walls 15 including portion P or Q. Furthermore, the number of cells 14 defined in the circumferential direction by the partition walls 15 including portion P is the same as the number of cells 14 defined in the circumferential direction by the partition walls 15 including portion Q. Controlling the number of cells 14 in the circumferential direction in this manner makes it easier to reduce the difference between the cell width on the central side and the cell width on the outer peripheral wall 11 side, thereby improving the heat recovery efficiency of the cells 14 on the outer peripheral wall 11 side.

[0068] The cells 14 defined by the first partition wall 15a and the second partition wall 15b preferably have substantially the same cell width in the circumferential direction. With this configuration, the flow path resistance in the circumferential direction becomes the same, and the first fluid can flow uniformly in the circumferential direction.

[0069] It is preferable that the honeycomb structure 10 has two or more regions having different numbers of cells 14 in the circumferential direction. For example, the honeycomb structure 10 shown in Fig. 11 has a region in which the number of cells 14 in the circumferential direction defined by partition walls 15 including part O is 32, and a region in which the number of cells 14 in the circumferential direction defined by partition walls 15 including part P or Q is 16. By controlling the honeycomb structure 10 to have such regions, it is possible to easily reduce the difference in cell width between the inner peripheral wall 16 side and the outer peripheral wall 11 side, thereby improving the heat recovery efficiency of the cells 14 on the outer peripheral wall 11 side.

[0070] As shown in Fig. 11, the first partition walls 15a may extend in a straight line from the inner peripheral wall 16 toward the outer peripheral wall 11. By using first partition walls 15a with such a structure, the heat transfer path of the first partition walls 15a is straight, and therefore the heat of the first fluid can be efficiently transferred to the outside of the honeycomb structure 10. On the other hand, if the first partition walls 15a do not extend in a straight line from the inner peripheral wall 16 toward the outer peripheral wall 11, the heat transfer path of the first partition walls 15a will bend (heat will need to be transferred via the second partition walls 15b), and therefore it will be difficult to efficiently transfer the heat of the first fluid to the outside of the honeycomb structure 10.

[0071] The partition walls 15 may include first partition walls 15a in which adjacent portions in the circumferential direction have different thicknesses. A cross-sectional view perpendicular to the axial direction of the honeycomb structure of a heat conduction member having such a structure is shown in Fig. 12. Even in a heat conduction member 800 including a honeycomb structure 10 having first partition walls 15a with such a structure, the difference between the cell width on the inner peripheral wall 16 side and the cell width on the outer peripheral wall 11 side can be easily reduced, thereby improving the heat recovery efficiency in the cells 14 on the outer peripheral wall 11 side.

[0072] The honeycomb structure 10 may have two or more regions including first partition walls 15a with different thicknesses in the circumferential direction. FIG. 13 shows a cross-sectional view of a heat conduction member having such a structure, taken perpendicular to the axial direction of the honeycomb structure. The honeycomb structure 10 in the heat conduction member 900 shown in FIG. 13 has two regions r3 and r4 including first partition walls 15a with different thicknesses in the circumferential direction. In an actual heat exchanger, depending on the position of the supply or discharge port for the second fluid flowing around the outer periphery of the outer peripheral wall 11 (or the covering member 20, if present), there may be regions in the circumferential direction of the honeycomb structure 10 where the heat of the first fluid is easily recovered and regions where the heat of the first fluid is difficult to recover. Therefore, by providing the region r3 including thick first partition walls 15a in the region where the heat of the first fluid is easily recovered and the region r4 including thin first partition walls 15a in the region where the heat of the first fluid is difficult to recover, the heat of the first fluid can be efficiently recovered.

[0073] The thickness of the outer peripheral wall 11 and the inner peripheral walls 16 and 15 (first partition wall 15a and second partition wall 15b) can be adjusted appropriately depending on the application. For example, the thicknesses of the outer peripheral wall 11, the second partition walls 15b, and the inner peripheral wall 16 can be made the same as those of the honeycomb structure 10 of the heat conduction member according to the first embodiment of the present invention. The thickness of the first partition wall 15a is preferably 0.05 to 1 mm, more preferably 0.1 to 0.8 mm, and further preferably 0.2 to 0.6 mm.

[0074] The heat conduction members 700, 800, and 900 according to the second embodiment of the present invention can be manufactured in the same manner as the heat conduction members 100, 200, 300, 400, 500, and 600 according to the first embodiment of the present invention. In particular, for the honeycomb structure 10 having a predetermined shape, the shape and density of the cells 14, the number, length, and thickness of the partition walls 15 (first partition walls 15a and second partition walls 15b), and the shapes and thicknesses of the outer peripheral wall 11 and inner peripheral wall 16 can be controlled by selecting appropriate types of die and jig when producing a honeycomb formed body.

[0075] The heat conduction members 700, 800, and 900 according to the second embodiment of the present invention include a honeycomb structure 10 in which the number of cells 14 closest to the outer peripheral wall 11 in the circumferential direction is greater than the number of cells 14 closest to the inner peripheral wall 16 in the circumferential direction. Therefore, the difference between the cell width on the central side and the cell width on the outer peripheral wall 11 side is small, and the cells 14 on the outer peripheral wall 11 side can recover heat to the same extent as the cells 14 on the central side.

[0076] (2) Heat exchanger A heat exchanger according to a second embodiment of the present invention includes the above-described heat conduction members 700, 800, and 900. The components other than the heat conduction members 700, 800, and 900 are not particularly limited, and known components can be used. For example, the heat exchanger according to the second embodiment of the present invention may include the heat conduction members 700, 800, and 900, and an outer cylinder (casing) disposed radially outward from and spaced apart from the covering member 20 of the heat conduction members 700, 800, and 900 so that the second fluid can flow around the outer periphery of the covering member 20. The heat exchanger according to the second embodiment of the present invention has the same structure as the heat exchanger according to the first embodiment of the present invention shown in Figures 8 and 9, except for the fact that it has the above-mentioned heat conduction members 700, 800, and 900, so detailed explanation will be omitted.

[0077] The heat exchanger according to the second embodiment of the present invention includes the heat conduction members 700, 800, and 900 described above, and therefore can improve heat recovery efficiency. [Example]

[0078] The present invention will be explained in more detail below with reference to examples, but the present invention is not limited to these examples in any way.

[0079] Example 1 A clay containing SiC powder was extruded into a desired shape, dried, processed to the specified outer dimensions, and then impregnated with silicon and fired to produce a hollow honeycomb structure (cylindrical) having a circular hollow region in a cross section perpendicular to the axial direction. Fig. 14 shows a partially enlarged cross section perpendicular to the axial direction of the honeycomb structure. The honeycomb structure had an outer diameter (outer diameter) of 90 mm, an inner diameter of 60 mm, an axial length (direction of the first fluid flow path) of 50 mm, outer and inner wall thicknesses of 2 mm, 250 first partition walls, and 4 second partition walls. The thickness of the first partition walls was 0.4 mm for a portion P1 that partitioned three cells from the outer wall toward the inner wall, 0.3 mm for a portion P2 that partitioned two cells from the inner wall toward the outer wall, and 0.3 mm for a portion P2 that partitioned two cells from the inner wall toward the outer wall. The thermal conductivity of the honeycomb structure (at 25°C) was set to 150 W / (m·K). Next, the honeycomb structure was shrink-fitted into a covering member to produce a heat transfer member. A stainless steel tubular member (thickness: 1 mm) was used as the covering member. Next, the heat transfer member was placed in an outer cylinder (casing: thickness: 1.5 mm), and both ends of the heat transfer member (covering member) were joined to the outer cylinder to produce a heat exchanger having a structure as shown in Figures 8 and 9.

[0080] Example 2 15 shows a partially enlarged cross-sectional view perpendicular to the axial direction of the honeycomb structure produced in Example 2. In Example 2, a honeycomb structure and a heat exchanger were produced under the same conditions as in Example 1, except that the thickness of all first partition walls was set to 0.3 mm, the number of first partition walls in portion P1 that defines three cells from the outer peripheral wall toward the inner peripheral wall was changed to 300, and the number of first partition walls in portion P2 that defines two cells from the inner peripheral wall toward the outer peripheral wall was changed to 250.

[0081] (Comparative Example 1) 16 shows a partially enlarged cross-sectional view perpendicular to the axial direction of the honeycomb structure produced in Comparative Example 1. In Comparative Example 1, a honeycomb structure and a heat exchanger were produced under the same conditions as in Example 1, except that the thickness of all the first partition walls was changed to 0.3 mm.

[0082] A heat exchange test was carried out on the heat exchangers produced in the above examples and comparative examples. The heat exchange test was carried out as follows. Air (first fluid) at a temperature of 400°C (Tg1) was flowed through the honeycomb structure of the heat exchanger at a flow rate (Mg) of 10 g / sec. Meanwhile, cooling water (second fluid) at 40°C was supplied from the second fluid supply pipe at a flow rate (Mw) of 10 L / min, and the cooling water after heat exchange was collected from the second fluid discharge pipe. Under the above conditions, immediately after starting to supply air and cooling water to the heat exchanger and passing them through for 5 minutes, the temperature of the cooling water at the inlet of the second fluid (Tw1) and the temperature of the cooling water at the outlet of the second fluid (Tw2) were measured, and the recovered heat quantity Q was calculated. Q(kW)=ΔTw[K]×Cpw[J / (kg·K)]×Pw[kg / m 3 ]×Mw[L / min]÷(60×10 6 ) In the formula, ΔTw = Tw2 - Tw1, Cpw (specific heat of water) = 4182 J / (kg·K), Pw (density of water) = 997 kg / m 3 It was decided. The results are shown in Table 1.

[0083] [Table 1]

[0084] As shown in Table 1, Examples 1 and 2 recovered more heat than Comparative Example 1. As can be seen from these results, the present invention can provide a heat transfer member and a heat exchanger that can improve heat recovery efficiency. [Explanation of symbols]

[0085] 10 Honeycomb structure 11 Peripheral wall 12 First end surface 13 Second end face 14 cells 15 Bulkhead 15a 1st bulkhead 15b 2nd bulkhead 16 Inner wall 20 Covering material 30 outer cylinder 31 Supply pipe 32 Discharge pipe 100,200,300,400,500,600,700,800,900 Thermal conductive material 1000 heat exchanger

Claims

1. A heat conduction member including a honeycomb structure having an outer peripheral wall and a plurality of partition walls disposed inside the outer peripheral wall and extending from a first end face to a second end face to define a plurality of cells that serve as flow paths for a first fluid, In a cross section of the honeycomb structure perpendicular to a flow path direction of the first fluid, the partition walls include a plurality of first partition walls extending in a radial direction and a plurality of second partition walls extending in a circumferential direction, At least a part of the first partition wall has a thickness of a portion that defines the cell and is closest to the outer peripheral wall, the thickness of a portion that defines the cell and is closest to a center portion, The partition walls include the first partition walls having portions with different thicknesses between adjacent portions in the circumferential direction.

2. A heat conduction member comprising a honeycomb structure having an outer peripheral wall and a plurality of partition walls disposed inside the outer peripheral wall and extending from a first end face to a second end face to define a plurality of cells that serve as flow paths for a first fluid, In a cross section of the honeycomb structure perpendicular to a flow path direction of the first fluid, the partition walls include a plurality of first partition walls extending in a radial direction and a plurality of second partition walls extending in a circumferential direction, At least a part of the first partition wall has a thickness of a portion that defines the cell and is closest to the outer peripheral wall, the thickness of a portion that defines the cell and is closest to a center portion, The honeycomb structure has two or more regions including the first partition walls whose thicknesses vary in the circumferential direction.

3. A heat conduction member as described in Claim 2, wherein the partition includes a first partition having adjacent portions with different thicknesses in the circumferential direction.

4. 4. The heat conduction member according to claim 1, wherein at least a portion of the first partition wall has three or more portions that define three or more of the cells in the radial direction, and the thickness of the portion that defines the cells located on the outer wall side is the same as or greater than the thickness of the portion that defines the cells located on the central side.

5. 5. The heat conduction member according to claim 1, wherein, of the cells partitioned by the first partition walls, the number of the cells closest to the outer peripheral wall in the circumferential direction is greater than the number of the cells closest to the center in the circumferential direction.

6. 6. The heat conduction member according to claim 5, wherein at least a portion of the first partition wall has three or more portions that define three or more of the cells in the radial direction, and the number of the cells located on the outer wall side in the circumferential direction is the same as or greater than the number of the cells located on the central side in the circumferential direction.

7. 7. The heat conduction member according to claim 1, wherein the thickness of the first partition wall gradually increases from the center toward the outer peripheral wall.

8. 8. The heat conduction member according to claim 1, wherein the first partition wall extends in a straight line from the center portion toward the outer peripheral wall.

9. The heat conduction member according to any one of claims 1 to 8, wherein the cells have substantially the same cell width in the circumferential direction.

10. 10. The heat transfer member according to claim 1, wherein the honeycomb structure further comprises an inner peripheral wall, and the partition walls are disposed between the outer peripheral wall and the inner peripheral wall.

11. A heat conduction member including a honeycomb structure having an outer peripheral wall, an inner peripheral wall, and partition walls disposed between the outer peripheral wall and the inner peripheral wall, the partition walls extending from a first end face to a second end face and defining a plurality of cells that serve as flow paths for a first fluid, In a cross section of the honeycomb structure perpendicular to a flow path direction of the first fluid, the partition walls include a plurality of first partition walls extending in a radial direction and a plurality of second partition walls extending in a circumferential direction, the number of the cells in the circumferential direction closest to the outer circumferential wall is greater than the number of the cells in the circumferential direction closest to the inner circumferential wall, The partition walls include the first partition walls having portions with different thicknesses between adjacent portions in the circumferential direction.

12. A heat conduction member comprising a honeycomb structure having an outer peripheral wall, an inner peripheral wall, and partition walls disposed between the outer peripheral wall and the inner peripheral wall, extending from a first end face to a second end face and defining a plurality of cells that serve as flow paths for a first fluid, In a cross section of the honeycomb structure perpendicular to a flow path direction of the first fluid, the partition walls include a plurality of first partition walls extending in a radial direction and a plurality of second partition walls extending in a circumferential direction, the number of the cells in the circumferential direction closest to the outer circumferential wall is greater than the number of the cells in the circumferential direction closest to the inner circumferential wall, The honeycomb structure has two or more regions including the first partition walls whose thicknesses vary in the circumferential direction.

13. A heat conduction member as described in Claim 12, wherein the partition includes a first partition having adjacent portions with different thicknesses in the circumferential direction.

14. The heat conduction member according to any one of claims 11 to 13, wherein the first partition wall has three or more portions that define three or more of the cells in the radial direction, and the number of the cells located on the outer wall side in the circumferential direction is the same as or greater than the number of the cells located on the inner wall side in the circumferential direction.

15. The heat conduction member according to any one of claims 11 to 14, wherein the cells have substantially the same cell width in the circumferential direction.

16. The heat conduction member according to any one of claims 11 to 14, wherein the honeycomb structure has two or more regions in which the number of cells in the circumferential direction is different.

17. The heat conduction member according to any one of claims 11 to 16, wherein the first partition wall extends in a straight line from the inner circumferential wall toward the outer circumferential wall.

18. 18. The heat conduction member according to claim 11, wherein the thickness of the inner circumferential wall is greater than the thickness of the second partition wall.

19. The heat conduction member according to any one of claims 1 to 18, wherein the honeycomb structure is made of a Si-SiC-based material.

20. The heat conduction member according to any one of claims 1 to 19, further comprising a covering member that covers an outer surface of the outer peripheral wall of the honeycomb structure.

21. The heat conduction member according to claim 20; an outer cylinder arranged radially outward from the covering member at a distance so that a second fluid can flow around the outer periphery of the covering member; A heat exchanger comprising:

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