Heat exchanger

Abstract

To provide a heat exchanger having excellent heat exchange performance.SOLUTION: A heat exchanger comprises a honeycomb structure 100 having: an outer peripheral wall 10; an intermediate wall 20 including a portion disposed inside the outer peripheral wall 10; an inside partition wall 30 disposed inside the intermediate wall 20, and defining a plurality of cells 50a that serve as flow paths for first fluid; and an outer partition wall 40 disposed between the outer peripheral wall 10 and the intermediate wall 20, and defining a plurality of cells 50b that serve as flow paths for second fluid. The heat exchanger has a thermal resistance ratio expressed by the following formula (1) of 0.05 to 8.0: thermal resistance ratio=(S2×R20.5) / (S1×R10.5).SELECTED DRAWING: Figure 1A

Description

[Technical Field]

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

[0002] Heat exchangers that use heat sources such as exhaust gas to preheat fuel air or steam have been introduced into various systems. For example, there are heat exchangers that preheat combustion air using exhaust gas from boilers used in thermal power plants as a heat source, and heat exchangers that generate and preheat steam using exhaust gas from fuel cells as a heat source. Systems that incorporate such heat exchangers are known to be effective in reducing energy consumption because they reuse waste heat energy from exhaust gas and other sources.

[0003] As a heat exchanger suitable for exchanging heat between gases used in the above technology, Patent Document 1 proposes a heat exchanger having a ceramic structure whose main component is ceramic, which has a three-dimensional mesh structure having partition walls and / or communicating pores that define cells in 2 x 2 or more rows that form a first fluid circulation section, which is a first flow path, and partition walls and / or the three-dimensional mesh structure that define cells that form a second fluid circulation section, which is a flow path for a second fluid, on its periphery via intermediate walls, and an outer periphery of the three-dimensional mesh structure, and at least one pair of inlet sections through which the second fluid flows into the second fluid circulation section from the outside and outlet sections that discharge the second fluid that has flowed into the second fluid circulation section to the outside are provided on part of the outer periphery wall. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-042934 Summary of the Invention [Problem to be solved by the invention]

[0005] The heat exchanger of Patent Document 1 may not be able to achieve the desired heat exchange performance depending on various conditions such as the flow rates of the first fluid and the second fluid. The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a heat exchanger having excellent heat exchange performance. [Means for solving the problem]

[0006] As a result of extensive research into a heat exchanger including a honeycomb structure having an outer peripheral wall, an intermediate wall, an inner partition wall, and an outer partition wall, the inventors have found that the above-mentioned problems can be solved by controlling the thermal resistance ratio, which is expressed using the contact areas and flow velocities of the first and second fluids, within a predetermined range, and have thus completed the present invention. That is, the present invention is exemplified as follows.

[0007] [1] A perimeter wall; an intermediate wall including a portion disposed inside the outer peripheral wall; an inner partition wall disposed inside the intermediate wall and defining a plurality of cells that serve as a flow path for a first fluid; an outer partition wall disposed between the outer peripheral wall and the intermediate wall, which partitions and forms a plurality of cells that serve as flow paths for a second fluid; A honeycomb structure having A heat exchanger having a thermal resistance ratio, expressed by the following formula (1), of 0.05 to 8.0. Thermal resistance ratio=(S2×R2 0.5 ) / (S1×R1 0.5 ) ···(1) In the formula, S1 is the contact area [m 2 ], and S2 is the contact area [m 2 ], R1 is the flow velocity [m / sec] of the first fluid represented by the following formula (2), and R2 is the flow velocity [m / sec] of the second fluid represented by the following formula (3). R1=B1 / (ρ1×A1) (2) R2=B2 / (ρ2×A2) (3) where B1 is the flow rate of the first fluid [kg / s], B2 is the flow rate of the second fluid [kg / s], and ρ1 is the density of the first fluid [kg / m 3 ], and ρ2 is the density of the second fluid [kg / m 3 ], and A1 is the cross-sectional area [m 2 ], and A2 is the cross-sectional area [m 2 ].

[0008] [2] A heat exchanger as described in [1], wherein in a cross section perpendicular to the direction in which the cells extend, the inner partition wall and the outer partition wall have a first partition wall extending in a circumferential direction and a second partition wall extending in a radial direction.

[0009] [3] The heat exchanger according to [2], wherein the thickness of the intermediate wall is greater than the thickness of the first partition wall.

[0010] [4] A heat exchanger described in any one of [1] to [3], further comprising a first outer cylindrical member fitted to at least a portion of the outer peripheral wall, the first outer cylindrical member having an inlet and an outlet for the second fluid.

[0011] [5] The heat exchanger according to [4], wherein the first outer casing member is made of a metal material.

[0012] [6] The heat exchanger according to any one of [1] to [5], wherein both end portions of the outer peripheral wall are located more inward than both end portions of the intermediate wall in the axial direction of the honeycomb structure.

[0013] [7] The heat exchanger according to [6], further comprising a second outer cylindrical member fitted to at least a portion of the intermediate wall.

[0014] [8] The heat exchanger according to [7], wherein the second outer casing member is made of a metal material.

[0015] [9] The heat exchanger according to any one of [1] to [8], wherein the flow direction of the first fluid is opposite to the flow direction of the second fluid.

[0016]

[10] The heat exchanger according to any one of [1] to [9], wherein the honeycomb structure is mainly composed of ceramics.

[0017]

[11] The heat exchanger according to

[10] , wherein the ceramic is mainly composed of silicon carbide.

[0018]

[12] The honeycomb structure further has an additional intermediate wall disposed inside the intermediate wall, A heat exchanger according to any one of [1] to

[11] , wherein a plurality of cells that serve as a flow path for the first fluid are formed between the intermediate wall and the additional intermediate wall, and a plurality of cells that serve as a flow path for a third fluid are formed inside the additional intermediate wall.

[0019]

[13] The heat exchanger according to any one of [1] to

[11] , wherein the honeycomb structure further has an inner peripheral wall that defines a hollow region inside the honeycomb structure, the hollow region serving as a flow path for a third fluid.

[0020]

[14] A heat exchanger as described in

[13] , further comprising an inner cylindrical member fitted to at least a portion of the inner circumferential wall, the inner cylindrical member having an inlet and an outlet for the third fluid. [Effects of the Invention]

[0021] According to the present invention, it is possible to provide a heat exchanger having excellent heat exchange performance. [Brief explanation of the drawings]

[0022] [Figure 1A] 1 is a cross-sectional view parallel to the extending direction of cells of a heat exchanger according to a first embodiment of the present invention. [Figure 1B] 1B is a cross-sectional view of the heat exchanger of FIG. 1A taken along line aa'. [Figure 2] FIG. 3 is a cross-sectional view of another heat exchanger according to the first embodiment of the present invention, taken along a line parallel to the extending direction of cells of the honeycomb structure. [Figure 3] FIG. 4 is a cross-sectional view parallel to the extending direction of the cells of a heat exchanger according to a second embodiment of the present invention. [Figure 4] FIG. 6 is a cross-sectional view parallel to the extending direction of the cells of another heat exchanger according to the second embodiment of the present invention. [Figure 5] FIG. 6 is a cross-sectional view parallel to the extending direction of the cells of a heat exchanger according to a third embodiment of the present invention. [Figure 6A] FIG. 10 is a cross-sectional view parallel to the extending direction of the cells of a heat exchanger according to a fourth embodiment of the present invention. [Figure 6B] FIG. 6B is a cross-sectional view of the heat exchanger of FIG. 6A taken along line bb'. [Figure 7A] FIG. 10 is a cross-sectional view parallel to the extending direction of the cells of a heat exchanger according to a fifth embodiment of the present invention. [Figure 7B] FIG. 7B is a cross-sectional view of the heat exchanger of FIG. 7A taken along line cc'. [Figure 8] FIG. 10 is a cross-sectional view parallel to the extending direction of the cells of a heat exchanger according to a sixth embodiment of the present invention. [Figure 9] 3 is a graph showing the relationship between the thermal resistance ratio of formula (1) and the amount of recovered heat in an example. DETAILED DESCRIPTION OF THE INVENTION

[0023] 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.

[0024] <Embodiment 1> Fig. 1A is a cross-sectional view parallel to the extension direction of the cells of the heat exchanger according to the first embodiment of the present invention, and Fig. 1B is a cross-sectional view of the heat exchanger of Fig. 1A taken along line a-a' (a cross-sectional view perpendicular to the extension direction of the cells of the heat exchanger of Fig. 1A). As shown in FIGS. 1A and 1B , the heat exchanger according to the first embodiment of the present invention includes a honeycomb structure 100 having an outer peripheral wall 10, intermediate walls 20, inner partition walls 30, and outer partition walls 40. The intermediate walls 20 include a portion disposed inside the outer peripheral wall 10. The inner partition walls 30 are disposed inside the intermediate walls 20 and define a plurality of cells 50a that serve as flow paths for a first fluid. The outer partition walls 40 are disposed between the outer peripheral wall 10 and the intermediate walls 20 and define a plurality of cells 50b that serve as flow paths for a second fluid. The honeycomb structure 100 having such a structure enables heat exchange between the first fluid and the second fluid. In this specification, the term "heat exchanger" refers to a device or component used to exchange thermal energy between two different fluids (e.g., a first fluid and a second fluid). When the term "heat exchanger" refers to a device, it may further include known components necessary to configure the device.

[0025] The heat exchanger has a thermal resistance ratio represented by the following formula (1) of 0.05 to 8.0, preferably 0.1 to 3.0, and more preferably 0.2 to 1.5. Thermal resistance ratio=(S2×R2 0.5 ) / (S1×R1 0.5 ) ···(1) In the formula, S1 is the contact area [m 2 ], and S2 is the contact area [m 2 ], R1 is the flow velocity [m / sec] of the first fluid expressed by the following equation (2), and R2 is the flow velocity [m / sec] of the second fluid expressed by the following equation (3). R1=B1 / (ρ1×A1) (2) R2=B2 / (ρ2×A2) (3) where B1 is the flow rate of the first fluid [kg / s], B2 is the flow rate of the second fluid [kg / s], and ρ1 is the density of the first fluid [kg / m 3 ] and ρ2 is the density of the second fluid [kg / m 3 ], and A1 is the cross-sectional area [m 2 ], and A2 is the cross-sectional area [m2 Here, the flow path cross-sectional area of ​​the first fluid means the total area of ​​the cells 50a in a cross section (for example, the cross-sectional view of FIG. 1B) parallel to the direction in which the cells 50a and 50b of the heat exchanger extend, and the flow path cross-sectional area of ​​the second fluid means the total area of ​​the cells 50b in the same cross section. By controlling the thermal resistance ratio of the heat exchanger within the above range, it is possible to prevent the heat exchange performance from decreasing due to conditions such as the flow rates of the first and second fluids. That is, by controlling the thermal resistance ratio of the heat exchanger within the above range, the heat exchange efficiency per unit area increases, making it possible to improve the heat exchange performance while making the heat exchanger more compact. The structure of the heat exchanger will be described in detail below.

[0026] (honeycomb structure 100) The honeycomb structure 100 has an outer peripheral wall 10, an intermediate wall 20 including a portion arranged inside the outer peripheral wall 10, an inner partition wall 30 arranged inside the intermediate wall 20 and defining a plurality of cells 50a which serve as flow paths for a first fluid, and an outer partition wall 40 arranged between the outer peripheral wall 10 and the intermediate wall 20 and defining a plurality of cells 50b which serve as flow paths for a second fluid. The shape of the honeycomb structure 100 is not particularly limited, and in a cross section perpendicular to the extension direction of the cells 50a, 50b, it can be circular as shown in FIG. 1B, as well as elliptical, rectangular, or other polygonal shapes. The shape of the cells 50a, 50b is not particularly limited, and in a cross section perpendicular to the direction in which the cells 50a, 50b extend, the shape may be a rectangle as shown in FIG. 1B, a circle, an ellipse, a triangle, a hexagon, or any other polygon.

[0027] The flow path for the first fluid and the flow path for the second fluid are preferably positioned coaxially as shown in Fig. 1A. Therefore, the outer wall 10 and the intermediate wall 20 that form these flow paths are also preferably positioned coaxially. By adopting such a configuration, it is possible to improve the heat exchange performance while making the heat exchanger more compact.

[0028] Since the peripheral wall 10 is the outer surface of the honeycomb structure 100, from the viewpoint of improving resistance to external impact, it is preferable that the thickness of the peripheral wall 10 is thicker than the partition walls (inner partition walls 30 and outer partition walls 40) that constitute the honeycomb structure 100. Specifically, the thickness of the peripheral wall 10 is preferably 1.2 to 15 times, and more preferably 1.5 to 10 times, the thickness of the partition walls. By controlling the thickness of the peripheral wall 10 to such a value, it is possible to improve resistance to external impact. The thickness of the outer peripheral wall 10 is not particularly limited, but is preferably 0.1 mm to 10 mm, more preferably 0.5 mm to 5 mm, and even more preferably 1 mm to 3 mm.

[0029] 1B, the inner partition wall 30 and the outer partition wall 40 preferably have first partition walls 31, 41 extending in the circumferential direction and second partition walls 32, 42 extending in the radial direction in a cross section perpendicular to the extension direction of the cells 50a, 50b of the honeycomb structure 100. With this configuration, heat exchange between the first fluid flowing through the cells 50a and the second fluid flowing through the cells 50b can be efficiently performed.

[0030] The intermediate wall 20 is a wall that exists between the flow path of the first fluid and the flow path of the second fluid. Therefore, the intermediate wall 20 preferably has a thickness that prevents the first fluid and the second fluid from mixing. Specifically, the thickness of the intermediate wall 20 is preferably larger than the thickness of the partition walls (the inner partition wall 30 and the outer partition wall 40) that constitute the honeycomb structure 100, particularly the first partition walls 31 and 41, and is more preferably 1.2 to 15 times, and even more preferably 1.5 to 10 times, the thickness of the partition walls. By controlling the thickness of the intermediate wall 20 to such a value, it is possible to increase the pressure resistance and prevent the fluids from mixing. The thickness of the intermediate wall 20 is not particularly limited, but is preferably 0.1 mm to 10 mm, more preferably 0.5 mm to 5 mm, and even more preferably 1 mm to 3 mm.

[0031] The thickness of the partition walls (inner partition walls 30 and outer partition walls 40) is not particularly limited, but is preferably 0.05 to 1.0 mm, and more preferably 0.2 to 0.6 mm. By making the thickness of the partition walls 0.05 mm or more, it is possible to ensure sufficient mechanical strength of the honeycomb structure 100. Furthermore, by making the thickness of the partition walls 1.0 mm or less, it is possible to suppress problems such as an increase in pressure loss due to a decrease in opening area and a decrease in heat exchange efficiency due to a decrease in contact area with the first fluid and the second fluid.

[0032] In the axial direction X of the honeycomb structure 100, both end portions (end portions 11, 12) of the outer peripheral wall 10 are preferably located more inward than both end portions (end portions 21, 22) of the intermediate wall 20. By locating both end portions of the outer peripheral wall 10 in such positions, it becomes easier to provide an inlet and an outlet for the second fluid flowing between the outer peripheral wall 10 and the intermediate wall 20, avoiding the flow of the first fluid.

[0033] The distance L1 between each end 11, 12 of the outer peripheral wall 10 and each end 21, 22 of the intermediate wall 20 may be adjusted appropriately depending on the overall size of the honeycomb structure 100, but is preferably 2 to 150 mm, more preferably 5 to 50 mm. By controlling the distance L1 in this way, it becomes easier to stably ensure the above-mentioned effects.

[0034] 2, a constricted portion 60 may be formed by not providing the outer peripheral wall 10 and the outer partition wall 40 in a part of the axial direction X of the honeycomb structure 100. Even when the constricted portion 60 is formed, it becomes easier to provide an inlet and an outlet for the second fluid flowing between the outer peripheral wall 10 and the intermediate wall 20, avoiding the flow of the first fluid. 2 is a cross-sectional view of the heat exchanger taken along a line parallel to the direction in which the cells 50a and 50b of the honeycomb structure 100 extend.

[0035] The position of the constricted portion 60 may be adjusted appropriately depending on the overall size of the honeycomb structure 100, but the distance L2 from the ends 11, 12 of the outer peripheral wall 10 to the constricted portion 60 is preferably 2 to 100 mm, more preferably 5 to 50 mm. The length L3 of the constricted portion 60 is preferably 3 to 100 mm, more preferably 5 to 50 mm.

[0036] The honeycomb structure 100 (the outer peripheral wall 10, the intermediate wall 20, the inner partition wall 30, and the outer partition wall 40) is mainly composed of ceramics. "Mainly composed of ceramics" means that the mass ratio of ceramics to the mass of all components is 50 mass% or more. By using ceramics, it is possible to reduce the weight while suppressing rust and deformation.

[0037] The ceramic is not particularly limited, but is preferably composed primarily of silicon carbide (SiC). Examples of ceramics containing silicon carbide (SiC) as the main component include Si-impregnated SiC, (Si+Al)-impregnated SiC, metal composite SiC, recrystallized SiC, Si3N4, and SiC. Among these, it is preferable to use Si-impregnated SiC and (Si+Al)-impregnated SiC because they can be produced inexpensively and have high thermal conductivity.

[0038] The porosity of the outer peripheral wall 10, the intermediate walls 20, the inner partition walls 30, and the outer partition walls 40 is not particularly limited, but is preferably 10% or less, more preferably 5% or less, and even more preferably 3% or less. By setting the porosity of the outer peripheral wall 10 and the partition walls 13 to 10% or less, the thermal conductivity can be improved. Here, the term "porosity" in this specification refers to the porosity measured by mercury intrusion porosimetry in accordance with JIS R1655:2003.

[0039] The cell density of the honeycomb structure 100 in a cross section perpendicular to the direction in which the cells 50a and 50b extend (i.e., the number of cells 50a and 50b per unit area) is not particularly limited, but is preferably 4 to 320 cells / cm. 2 The cell density is 4 cells / cm 2By setting the cell density to the above, it is possible to sufficiently secure the strength of the partition walls, and in turn the strength and effective GSA (geometric surface area) of the honeycomb structure 100 itself. 2 By setting the above, it is possible to suppress an increase in pressure loss when the first fluid and the second fluid flow.

[0040] The isostatic strength of the honeycomb structure 100 is not particularly limited, but is preferably 100 MPa or more, more preferably 150 MPa or more, and even more preferably 200 MPa or more. By making the isostatic strength of the honeycomb structure 100 100 MPa or more, the durability of the honeycomb structure 100 can be improved. Here, the "isostatic strength" in this specification can be measured in accordance with the method for measuring isostatic strength specified in JASO standard M505-87, an automotive standard issued by the Society of Automotive Engineers of Japan.

[0041] The diameter (outer diameter) of the outer peripheral wall 10 of the honeycomb structure 100 in a cross section perpendicular to the extension direction of the cells 50a, 50b is not particularly limited, but is preferably 20 to 200 mm, more preferably 30 to 150 mm. By setting the diameter in this range, it is possible to improve the heat exchange efficiency. When the outer peripheral wall 10 is not circular, the diameter of the outer peripheral wall 10 is defined as the diameter of the largest inscribed circle inscribed in the cross-sectional shape of the outer peripheral wall 10.

[0042] The thermal conductivity of the honeycomb structure 100 is not particularly limited, but 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) at 25° C. By setting the thermal conductivity of the honeycomb structure 100 within this range, the thermal conductivity is improved, and therefore heat exchange between the first fluid flowing through the cells 50a of the honeycomb structure 100 and the second fluid flowing through the cells 50b can be efficiently performed. Here, the term "thermal conductivity" in this specification refers to a value measured by the laser flash method (JIS R1611:1997).

[0043] (First fluid and second fluid) The first fluid and the second fluid are not particularly limited and may be gas, liquid, or the like. Typically, the first fluid and the second fluid are gas. For example, the first fluid is exhaust gas emitted in industrial fields, and the second fluid is various gases that require heating. It is preferable that the flow direction of the first fluid and the flow direction of the second fluid are opposite to each other, which can improve the efficiency of heat exchange between the first fluid and the second fluid.

[0044] (Method for manufacturing honeycomb structure 100) The honeycomb structure 100 can be manufactured in accordance with a method known in the art. For example, the honeycomb structure 100 can be manufactured according to the method described below. First, a clay containing ceramic powder is extruded into a desired shape to produce a honeycomb molded body. By selecting an appropriate die and jig, the thickness of the outer peripheral wall 10, the intermediate wall 20, and each partition wall (inner partition wall 30 and outer partition wall 40), the shape of each cell (50a, 50b), and the cell density can be controlled. For example, when producing a honeycomb molded body whose main component is a Si-impregnated SiC composite material, a binder and water or an organic solvent are added to a predetermined amount of SiC powder, and the resulting mixture is kneaded to form a clay, which is then molded to produce a honeycomb molded body of the desired shape.

[0045] Next, after drying the honeycomb formed body, portions of the outer peripheral wall 10 and the outer partition walls 40 are removed to form a desired shape. For example, when manufacturing a honeycomb structure 100 having the structure shown in FIG. 1A, both end side regions of the outer peripheral wall 10 and the outer partition walls 40 may be removed by grinding or the like. When manufacturing a honeycomb structure 100 having the structure shown in FIG. 2, the region of the outer peripheral wall 10 and the outer partition walls 40 that will become the constricted portion 60, and one end side region of the outer peripheral wall 10 and the outer partition walls 40 may be removed by grinding or the like. Next, the honeycomb formed body processed as described above is impregnated with metal Si and fired in a reduced pressure inert gas or in a vacuum, whereby the honeycomb structure 100 can be obtained. In the above description, the honeycomb formed body is subjected to processing for removing a portion of the outer peripheral wall 10 and the outer partition walls 40, but this processing may be performed after firing the honeycomb formed body.

[0046] <Embodiment 2> 3 and 4 are cross-sectional views parallel to the direction in which the cells of the heat exchanger according to the second embodiment of the present invention extend. In Figs. 3 and 4, components denoted by the same reference numerals as those in the above figures indicate the same components, and therefore detailed description thereof will be omitted. 3 and 4, the heat exchanger according to the second embodiment of the present invention further includes a first outer cylindrical member 110 fitted to at least a part of the outer peripheral wall 10. The first outer cylindrical member 110 has an inlet 111 and an outlet 112 for the second fluid. By adopting such a structure, the honeycomb structure 100 can be protected, and the inlet 111 and the outlet 112 for the second fluid flowing between the outer peripheral wall 10 and the intermediate wall 20 can be easily arranged away from the flow of the first fluid. Note that Figure 3 corresponds to an example in which a first outer tube member 110 is provided on the outer wall 10 of the honeycomb structure 100 of Figure 1A, and Figure 4 corresponds to an example in which a first outer tube member 110 is provided on the outer wall 10 of the honeycomb structure 100 of Figure 2.

[0047] It is preferable that the first outer cylinder member 110 is longer than the length of the outer peripheral wall 10 in the axial direction X. By setting the length of the first outer cylinder member 110 in this manner, the degree of freedom in installing the inlet 111 and outlet 112 for the second fluid is improved. For example, as shown in Fig. 3, the outlet 112 for the second fluid can be installed at a position perpendicular to the flow direction of the second fluid.

[0048] The first outer tubular member 110 preferably has heat resistance and corrosion resistance and can be made of a ceramic material or a metal material, but is preferably made of a metal material from the viewpoint of manufacturing costs, etc. Examples of metal materials that can be used include stainless steel, titanium alloys, copper alloys, aluminum alloys, brass, nickel alloys, steel, lead, and lead alloys. Among these, stainless steel is preferred because it is inexpensive and has high durability and reliability. Furthermore, in order to improve the corrosion resistance of the first outer tubular member 110, the first outer tubular member 110 may be subjected to a surface treatment such as a fluororesin lining or FRP lining.

[0049] The first outer cylinder member 110 is preferably fitted over the entire outer peripheral wall 10 of the honeycomb structure 100. Here, in this specification, "fitted" means fixed in a mutually fitted state. Therefore, the fitting of the honeycomb structure 100 and the first outer cylinder member 110 includes fixing methods using fitting such as clearance fitting, interference fitting, and shrink fitting, as well as cases where the honeycomb structure 100 and the first outer cylinder member 110 are fixed to each other by brazing, welding, diffusion bonding, etc. When the first outer cylindrical member 110 is made of a ceramic material, it is preferable that the first outer cylindrical member 110 and the honeycomb structure 100 are integrally formed. Furthermore, from the viewpoint of durability and reliability against thermal stress, it is preferable that the first outer cylindrical member 110 and the honeycomb structure 100 are made of the same material or materials with similar thermal expansion coefficients.

[0050] A heat insulating material may be further disposed between the honeycomb structure 100 and the first outer tubular member 110. By providing the heat insulating material, heat radiation from the first outer tubular member 110 to the external space can be suppressed, and therefore, the heat exchange efficiency between the first fluid and the second fluid can be improved. The heat insulating material is not particularly limited as long as it is a material having heat insulating properties, and examples thereof include glass wool, rock wool, and cellulose fiber.

[0051] The heat exchanger according to the second embodiment of the present invention can be manufactured in accordance with a method known in the art. Specifically, the first outer casing member 110 can be fitted to the outer peripheral wall 10 of the honeycomb structure 100. The fitting method can be the method described above.

[0052] <Embodiment 3> Fig. 5 is a cross-sectional view parallel to the extension direction of the cells of a heat exchanger according to embodiment 3 of the present invention. In Fig. 5, components denoted by the same reference numerals as those in the above figures indicate the same components, and therefore detailed description thereof will be omitted. 5, the heat exchanger according to the third embodiment of the present invention further includes a second outer tubular member 120 fitted to at least a part of the intermediate wall 20. With such a structure, it becomes easy to provide an inlet 111 and an outlet 112 for the second fluid flowing between the outer circumferential wall 10 and the intermediate wall 20, avoiding the flow of the first fluid.

[0053] The heat exchanger according to the third embodiment of the present invention may further include a first outer casing member 110. In this case, it is preferable that the second outer casing member 120 is partially joined to the first outer casing member 110. In Fig. 5, the second outer casing member 120 and the first outer casing member 110 are joined by providing flanges on the two, but the second outer casing member 120 and the first outer casing member 110 may also be joined by expanding the diameter of the second outer casing member 120 or reducing the diameter of the first outer casing member 110. When the first outer casing member 110 is provided, an inlet 111 and an outlet 112 for the second fluid are formed in the first outer casing member 110. Although FIG. 5 shows an example in which the first outer cylindrical member 110 is fitted to at least a part of the outer peripheral wall 10, the first outer cylindrical member 110 does not necessarily have to be provided.

[0054] The second outer casing member 120 preferably has heat resistance and corrosion resistance, and like the first outer casing member 110, can be made of a ceramic material or a metal material, but is preferably made of a metal material from the viewpoint of manufacturing costs, etc. Furthermore, the second outer casing member 120 may be made of the same material as the first outer casing member 110 or a different material. Furthermore, from the viewpoint of improving the corrosion resistance of the second outer casing member 120, the second outer casing member 120 may be subjected to a surface treatment such as a fluororesin lining or an FRP lining. The second outer cylindrical member 120 is fitted to a part of the intermediate wall 20 that is exposed on the surface (the surface on which the outer peripheral wall 10 and the outer partition wall 40 are not provided). The fitting of the intermediate wall 20 and the second outer cylindrical member 120 can be carried out by the method described above.

[0055] The heat exchanger according to the third embodiment of the present invention can be manufactured in accordance with a method known in the art. Specifically, the second outer cylindrical member 120 can be fitted to the intermediate wall 20 of the honeycomb structure 100. The fitting method can be the method described above.

[0056] <Embodiment 4> Fig. 6A is a cross-sectional view parallel to the extension direction of the cells of a heat exchanger according to embodiment 4 of the present invention. Fig. 6B is a cross-sectional view of the heat exchanger of Fig. 6A taken along line b-b' (a cross-sectional view perpendicular to the extension direction of the cells of the heat exchanger of Fig. 6A). In Figs. 6A and 6B, components denoted by the same reference numerals as those in the above figures indicate the same components, and therefore detailed description thereof will be omitted. 6A and 6B, the heat exchanger according to the fourth embodiment of the present invention differs from the heat exchanger according to the first embodiment of the present invention in that it further includes an additional intermediate wall 70 disposed inside the intermediate wall 20, and has a plurality of cells 50a that serve as flow paths for a first fluid between the intermediate wall 20 and the additional intermediate wall 70, and a plurality of cells 50c that serve as flow paths for a third fluid formed inside the additional intermediate wall 70. The cells 50a are defined by the inner partition walls 30, and the cells 50c are defined by the additional inner partition walls 80. A heat exchanger including a honeycomb structure 200 having such a structure enables heat exchange between the first fluid and the second and third fluids.

[0057] The additional intermediate wall 70 is a wall that exists between the flow path of the first fluid and the flow path of the third fluid. Therefore, the additional intermediate wall 70 preferably has a thickness that prevents the first fluid and the third fluid from mixing. Specifically, the thickness of the additional intermediate wall 70 is preferably larger than the thickness of the partition walls (inner partition walls 30, outer partition walls 40, and additional inner partition walls 80) that constitute the honeycomb structure 200, more preferably 1.2 to 15 times the thickness of the partition walls, and even more preferably 1.5 to 10 times the thickness of the partition walls. By controlling the thickness of the additional intermediate wall 70 in this range, it is possible to increase the pressure resistance and prevent the fluids from mixing. The thickness of the additional intermediate wall 70 is not particularly limited, but is preferably 0.1 mm to 10 mm, more preferably 0.5 mm to 5 mm, and even more preferably 1 mm to 3 mm.

[0058] The thickness of the additional inner partition wall 80 is not particularly limited, but is preferably 0.1 to 1 mm, and more preferably 0.2 to 0.5 mm. By controlling the thickness of the additional inner partition wall 80 within this range, it is possible to increase the mechanical strength and heat exchange efficiency while suppressing the pressure loss of the third fluid. The shape of the cells 50c can be various shapes such as a circle, an ellipse, a triangle, a rectangle, a hexagon, or other polygons in a cross section perpendicular to the extension direction of the cells 50c. Furthermore, the shape of the cells 50c may be the same as or different from the shapes of the cells 50a and 50b.

[0059] The third fluid is not particularly limited and may be a gas, a liquid, etc. A typical third fluid is a gas. For example, various gases that require heating can be used as the third fluid. It is preferable that the flow direction of the first fluid and the flow direction of the third fluid are opposite to each other, which can improve the efficiency of heat exchange between the first fluid and the third fluid.

[0060] The heat exchanger according to the fourth embodiment of the present invention, like the heat exchangers according to the second and third embodiments of the present invention, can further include a first outer casing member 110 and / or a second outer casing member 120. By providing the first outer casing member 110 and / or the second outer casing member 120, it is possible to obtain the same effects as the heat exchangers according to the second and third embodiments.

[0061] The heat exchanger according to the fourth embodiment of the present invention can be manufactured in accordance with a method known in the art. Specifically, it can be manufactured by the same method as the heat exchanger according to the first embodiment of the present invention, except that a honeycomb formed body is manufactured by selecting a die and a jig of an appropriate shape so as to obtain a honeycomb structure 200 having the additional intermediate wall 70 and the additional inner partition wall 80. Furthermore, when the first outer tubular member 110 and / or the second outer tubular member 120 is provided, it can be manufactured by the same method as the heat exchangers according to the second and third embodiments of the present invention.

[0062] <Embodiment 5> Fig. 7A is a cross-sectional view parallel to the extension direction of the cells of a heat exchanger according to embodiment 5 of the present invention. Fig. 7B is a cross-sectional view of the heat exchanger of Fig. 7A taken along line c-c' (a cross-sectional view perpendicular to the extension direction of the cells of the heat exchanger of Fig. 7A). In Figs. 7A and 7B, components denoted by the same reference numerals as those in the above figures indicate the same components, and therefore detailed description thereof will be omitted. 7A and 7B, the heat exchanger according to the fifth embodiment of the present invention differs from the heat exchanger according to the first embodiment of the present invention in that it further includes an inner circumferential wall 90 that defines a hollow region 95 therein, which serves as a flow path for the third fluid. With this configuration, heat exchange between the first fluid and the third fluid can be performed via the inner circumferential wall 90.

[0063] Although the thickness of the inner circumferential wall 90 is not particularly limited, it is preferably larger than the thickness of the partition walls (the inner partition wall 30 and the outer partition wall 40). By adopting such a configuration, it is possible to increase the strength of the inner circumferential wall 90, which is prone to damage (for example, cracks, fractures, etc.) due to thermal stress caused by the temperature difference between the first fluid and the third fluid. The thickness of the inner peripheral wall 90 is not particularly limited and may be adjusted appropriately depending on the application, etc. For example, the thickness of the inner peripheral wall 90 is preferably 0.1 mm to 10 mm, more preferably 0.5 mm to 5 mm, and even more preferably 1 mm to 3 mm.

[0064] The shape of the inner peripheral wall 90 is not particularly limited, and in a cross section perpendicular to the direction in which the cells 50a, 50b extend, it may be a circle as shown in Fig. 7B, or an ellipse, a rectangle, or another polygon. Note that the shape of the outer peripheral wall 10 and the shape of the inner peripheral wall 90 may be the same or different, but from the viewpoint of resistance to thermal stress, it is preferable that they are the same. Furthermore, the diameter (inner diameter) of the inner peripheral wall 90 in a cross section perpendicular to the extension direction of the cells 50a, 50b is not particularly limited, but is preferably 150 mm or less, and more preferably 100 mm or less. When the cross-sectional shape of the inner peripheral wall 90 is not circular, the diameter of the inner peripheral wall 90 is defined as the diameter of the largest inscribed circle inscribed in the cross-sectional shape of the inner peripheral wall 90.

[0065] The heat exchanger according to the fifth embodiment of the present invention, like the heat exchangers according to the second and third embodiments of the present invention, can further include a first outer casing member 110 and / or a second outer casing member 120. By providing the first outer casing member 110 and / or the second outer casing member 120, it is possible to obtain the same effects as the heat exchangers according to the second and third embodiments.

[0066] The heat exchanger according to the fifth embodiment of the present invention can be manufactured in accordance with a method known in the art. Specifically, it can be manufactured in the same manner as the heat exchanger according to the first embodiment of the present invention, except that a honeycomb formed body is manufactured by selecting a die and a jig of an appropriate shape so as to obtain a honeycomb structure 300 having an inner peripheral wall 90. Furthermore, when the first outer cylindrical member 110 and / or the second outer cylindrical member 120 is provided, it can be manufactured in the same manner as the heat exchangers according to the second and third embodiments of the present invention.

[0067] <Embodiment 6> Fig. 8 is a cross-sectional view parallel to the extension direction of the cells of a heat exchanger according to embodiment 6 of the present invention. In Fig. 8, components denoted by the same reference numerals as those in the above figures indicate the same components, and therefore detailed description thereof will be omitted. 8, the heat exchanger according to the sixth embodiment of the present invention differs from the heat exchanger according to the fifth embodiment of the present invention in that it further includes an inner cylindrical member 130 fitted to at least a part of the inner circumferential wall 90. With this configuration, it is possible to stably suppress mixing of the first fluid and the third fluid.

[0068] The inlet (end) 131 and the outlet (end) 132 of the inner cylindrical member 130 are preferably positioned outside both end portions 11, 12 of the honeycomb structure 300 in the axial direction of the honeycomb structure 300. With this configuration, the inlet 131 and the outlet 132 for the third fluid can be easily provided away from the flow of the first fluid.

[0069] The inner cylindrical member 130 preferably has heat resistance and corrosion resistance, and like the first outer cylindrical member 110 and the second outer cylindrical member 120, can be made of a ceramic material or a metal material, but is preferably made of a metal material from the viewpoint of manufacturing costs, etc. Furthermore, the inner cylindrical member 130 may be made of the same material as the first outer cylindrical member 110 and the second outer cylindrical member 120, or a different material. Furthermore, from the viewpoint of improving the corrosion resistance of the inner cylindrical member 130, the inner cylindrical member 130 may be subjected to a surface treatment such as a fluororesin lining or an FRP lining. The inner cylindrical member 130 is preferably fitted over the entire inner circumferential wall 90. The fitting of the inner circumferential wall 90 and the inner cylindrical member 130 can be carried out by the method described above.

[0070] From the viewpoint of stably suppressing mixing of the first fluid and the third fluid, the inner cylindrical member 130 has a thickness of 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 inner cylindrical member 130 is preferably 50 mm or less, more preferably 40 mm or less, and even more preferably 30 mm or less.

[0071] At least one end (the inlet 131 or the outlet 132) of the inner cylindrical member 130 may be reduced or expanded in diameter. By reducing or expanding the diameter of the end of the inner cylindrical member 130, advantageous effects can be obtained in terms of manufacturing, such as making it easier to connect to other members.

[0072] The heat exchanger according to the sixth embodiment of the present invention, like the heat exchangers according to the second and third embodiments of the present invention, can further include a first outer casing member 110 and / or a second outer casing member 120. By providing the first outer casing member 110 and / or the second outer casing member 120, it is possible to obtain the same effects as the heat exchangers according to the second and third embodiments.

[0073] The heat exchanger according to the sixth embodiment of the present invention can be manufactured in accordance with a method known in the art. Specifically, after the honeycomb structure 300 is manufactured in accordance with the manufacturing method of the heat exchanger according to the sixth embodiment of the present invention, the inner cylindrical member 130 is fitted to the inner peripheral wall 90 of the honeycomb structure 300. The fitting method may be the same as that described above. [Example]

[0074] 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.

[0075] Example 1 A honeycomb molded body was fabricated by extrusion molding a clay containing SiC powder into the desired shape. The thickness of the outer wall, intermediate walls, and partition walls (inner and outer partition walls), the shape of each cell, and cell density were controlled by selecting the appropriate die and jig. The resulting honeycomb molded body was then dried and processed into the shape shown in Figures 1A and 1B by removing the end regions of the outer wall and outer partition walls by grinding. The honeycomb structure was then obtained by silicon impregnation and firing. The honeycomb structure had a porosity of 2%, a diameter of the outer wall of 75 mm, and a thermal conductivity (25°C) of 150 W / (m·K). Table 1 lists the details of the honeycomb structures fabricated and used in the simulation.

[0076] [Table 1]

[0077] A heat exchange test was carried out on the honeycomb structure (heat exchanger) produced above. The heat exchange test was carried out as follows. Air (first fluid) at a temperature of 400°C was flowed through the first fluid flow path of the honeycomb structure at a flow rate B1 shown in Table 2. Gas (second fluid) at a temperature of 25°C was flowed through the second fluid flow path of the honeycomb structure at a flow rate B2 shown in Table 2, and the gas after heat exchange was recovered. Under these conditions, after the supply of air and gas to the honeycomb structure was started and the gas temperature at the second fluid outlet became stable, the gas temperature (Tg1) at the second fluid inlet and the gas temperature (Tg2) at the second fluid outlet were measured, and the recovered heat quantity Q was calculated. Q(kW)=ΔTg[K]×Cpg[J / (kg·K)]×Mg[kg / sec]×10 -3 In the formula, ΔTg = Tg2 - Tg1, and Cpg (specific heat of gas) = ​​1050 J / (kg·K). The results of the amount of recovered heat Q were evaluated according to the diameter of the outer peripheral wall as a relative ratio (recovered heat amount ratio) based on Examples 1, 4, and 7. In this evaluation, if the recovered heat amount ratio is 0.5 or more, it can be determined that the amount of recovered heat is large. The above heat exchange test was simulated for some honeycomb structures using Ansys Fluent Ver. 19.1 software. The results are shown in Table 2. In Table 2, the ".E" in the contact area S1 of the first fluid, the contact area S2 of the second fluid, the cross-sectional area A1 of the flow path of the first fluid, and the cross-sectional area A2 of the flow path of the second fluid indicates "×10", and the number after ".E" indicates a multiplier. Therefore, for example, ".E-0.1" indicates "×10 -1 " means. FIG. 9 shows a graph showing the relationship between the thermal resistance ratio of formula (1) and the amount of recovered heat Q.

[0078] [Table 2]

[0079] As shown in Table 2, the honeycomb structures of Examples 1 to 9 had a thermal resistance ratio within the range of 0.05 to 8.0, and therefore recovered a large amount of heat. In contrast, the honeycomb structures of Comparative Examples 1 to 6 had a thermal resistance ratio outside the range of 0.05 to 8.0, and therefore the amount of recovered heat was small. Furthermore, as shown in Figure 9, even if the diameter of the outer wall is different, the same tendency is observed in equation (1), and it was confirmed that the amount of recovered heat can be improved by setting the thermal resistance ratio within the range of 0.05 to 8.0.

[0080] As can be seen from the above results, the present invention can provide a heat exchanger with excellent heat exchange performance. [Explanation of symbols]

[0081] 10 Peripheral wall 11,12 End 20 Intermediate Wall 21,22 End 30 Inner bulkhead 31 1st bulkhead 32 Second bulkhead 40 Outer bulkhead 41 1st bulkhead 42 Second bulkhead 50a, 50b cells 60 Neck 70 Additional intermediate wall 80 Additional inner bulkhead 90 Inner wall 95 Hollow area 100,200,300 Honeycomb structure 110 First outer cylindrical member 120 second outer cylindrical member 130 Inner cylinder member

Claims

1. The outer wall, an intermediate wall including a portion disposed inside the outer peripheral wall; an inner partition wall disposed inside the intermediate wall and defining a plurality of cells that serve as a flow path for a first fluid; an outer partition wall disposed between the outer peripheral wall and the intermediate wall, the outer partition wall defining a plurality of cells that serve as flow paths for a second fluid; A honeycomb structure having A heat exchanger having a thermal resistance ratio represented by the following formula (1) of 0.05 to 8.

0. Thermal resistance ratio = (S 2 ×R 2 0.5 ) / (S 1 ×R 1 0.5 ) ・・・(1) In the formula, S 1 is the contact area [m 2 ] and S 2 is the contact area [m 2 ] and R 1 is the flow velocity [m / sec] of the first fluid represented by the following formula (2), and R 2 is the flow velocity [m / sec] of the second fluid expressed by the following formula (3). R 1 =B 1 / (p 1 ×A 1 ) ・・・(2) R 2 =B 2 / (p 2 ×A 2 ) ・・・(3) In the formula, B 1 is the flow rate of the first fluid [kg / sec], and B 2 is the flow rate of the second fluid [kg / sec], and ρ 1 is the density of the first fluid [kg / m 3 ] and ρ 2 is the density of the second fluid [kg / m 3 ] and A 1 is the flow path cross-sectional area [m 2 ] and A 2 is the cross-sectional area [m 2 ].

2. 2. The heat exchanger according to claim 1, wherein in a cross section perpendicular to the direction in which the cells extend, the inner partition wall and the outer partition wall have a first partition wall extending in a circumferential direction and a second partition wall extending in a radial direction.

3. The heat exchanger according to claim 2 , wherein the thickness of the intermediate wall is greater than the thickness of the first partition wall.

4. A heat exchanger as described in any one of claims 1 to 3, further comprising a first outer cylindrical member fitted to at least a portion of the outer peripheral wall, the first outer cylindrical member having an inlet and an outlet for the second fluid.

5. The heat exchanger according to claim 4 , wherein the first outer casing member is made of a metal material.

6. 4. The heat exchanger according to claim 1, wherein both end portions of the outer peripheral wall are located more inward than both end portions of the intermediate wall in the axial direction of the honeycomb structure.

7. The heat exchanger according to claim 6 , further comprising a second outer casing member fitted to at least a portion of the intermediate wall.

8. The heat exchanger according to claim 7 , wherein the second outer casing member is made of a metallic material.

9. 4. The heat exchanger according to claim 1, wherein a flow direction of the first fluid and a flow direction of the second fluid are opposite to each other.

10. 4. The heat exchanger according to claim 1, wherein the honeycomb structure is mainly composed of ceramics.

11. The heat exchanger according to claim 10, wherein the ceramic is mainly composed of silicon carbide.

12. The honeycomb structure further includes an additional intermediate wall disposed inside the intermediate wall, 4. The heat exchanger according to claim 1, wherein a plurality of cells serving as a flow path for the first fluid are formed between the intermediate wall and the additional intermediate wall, and a plurality of cells serving as a flow path for a third fluid are formed inside the additional intermediate wall.

13. 4. The heat exchanger according to claim 1, wherein the honeycomb structure further has an inner peripheral wall that defines a hollow region therein, the hollow region serving as a flow path for a third fluid.

14. The heat exchanger according to claim 13 , further comprising an inner cylindrical member fitted to at least a portion of the inner circumferential wall, the inner cylindrical member having an inlet and an outlet for the third fluid.

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