Heat exchanger

Abstract

To perform heat exchange between a first fluid and a second fluid while suppressing increase in size of a heat exchange member.SOLUTION: A heat exchanger 7 includes a plurality of heat exchange members 5 and an outer wall part 6. Each of the plurality of heat exchange members 5 is a structure in which an outer peripheral surface of a honeycomb structure 1 is covered by a cylindrical covering part 4. The honeycomb structure 1 has a cylindrical outer peripheral wall, and a partition wall partitioning an internal space of the outer peripheral wall and extending in an axial direction. The partition wall forms a plurality of cells in which a first fluid flows. The plurality of heat exchange members 5 are arranged in parallel with each other at the same position in the axial direction. The outer wall part 6 forms a second flow passage 70 in which a second fluid flows which exchanges heat with the first fluid between itself and an outer peripheral surface of each of the plurality of heat exchange members 5, by covering the outer peripheral surface of each of the plurality of heat exchange members 5 in a state of being separated to the outside from the outer peripheral surface of each of the plurality of heat exchange members 5. Thereby, heat exchange between the first fluid and the second fluid can be performed efficiently, while suppressing increase in size of the heat exchange member 5.SELECTED DRAWING: Figure 1

Description

[Technical field]

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

[0002] In recent years, there has been a demand for improved fuel efficiency in automobiles. For example, to improve fuel efficiency when the engine temperature is low, such as when the engine is started, there is a demand for technology that can quickly heat engine oil and automatic transmission fluid (ATF) and reduce friction loss. There is also a demand for technology that can quickly heat up catalysts for purifying exhaust gases in order to quickly activate them. In addition to automobiles, there is also a demand for technology that can quickly heat up catalysts in order to quickly activate them. In addition to automobiles, there are also many factories, such as metal factories, ceramic factories, pulp and paper factories, chemical factories, and food factories, that are working to reduce CO2 emissions in order to become carbon neutral. 2 From the perspective of reduction and energy conservation measures, there is a demand for effective use of the thermal energy contained in exhaust gases, hot water, steam, etc.

[0003] To meet these technical demands, for example, heat exchangers are used. In the heat exchangers, heat is recovered from a high-temperature fluid (e.g., exhaust gas) and transferred to a low-temperature fluid (e.g., cooling water). The heat transferred to the cooling water or the like is utilized for various purposes as described above.

[0004] As such a heat exchanger, for example, one has been proposed that includes a columnar honeycomb structure having a plurality of cells that serve as a flow path for a first fluid, an inner tube member that is fitted into the outer wall surface of the honeycomb structure, and an outer tube member that is arranged radially outside the inner tube member at a distance so as to form a flow path for a second fluid (Patent Document 1). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent Publication No. 2021-42922 Summary of the Invention [Problem to be solved by the invention]

[0006] However, in order to increase the amount of heat recovered in a heat exchanger such as that in Patent Document 1, it is necessary to increase the size of the honeycomb structure, which is a heat exchange member. Specifically, it is necessary to increase the diameter of the columnar honeycomb structure or to increase the axial length of the honeycomb structure. However, when the diameter of the honeycomb structure is increased, the distance between the first fluid flowing through the cells in the vicinity of the central axis of the honeycomb structure and the second fluid flowing on the radially outer side of the honeycomb structure increases, so that the amount of heat recovered per unit volume of the honeycomb structure may decrease. Furthermore, when the axial length of the honeycomb structure is increased, the temperature of the first fluid is significantly decreased at the downstream side of the honeycomb structure, and the temperature difference between the first fluid and the second fluid is reduced, so that the amount of heat recovered per unit volume of the honeycomb structure may decrease.

[0007] The present invention has been made in consideration of the above problems, and has an object to efficiently exchange heat between a first fluid and a second fluid while suppressing an increase in size of a heat exchange member. [Means for solving the problem]

[0008] A first aspect of the present invention is a heat exchanger, comprising a honeycomb structure having a cylindrical outer surface covered with a cylindrical covering portion, the honeycomb structure having a cylindrical outer wall and partition walls that divide the internal space of the outer wall, extend in the axial direction, and form a plurality of cells through which a first fluid flows, and the heat exchanger comprises a plurality of heat exchange elements arranged in parallel at the same position in the axial direction, and an outer wall portion covering the outer surfaces of the plurality of heat exchange elements while being spaced outward from the outer surfaces of the plurality of heat exchange elements, thereby forming a flow path between the outer surfaces of the plurality of heat exchange elements and the outer wall of the plurality of heat exchange elements through which a second fluid flows and which exchanges heat with the first fluid.

[0009] A second aspect of the present invention is the heat exchanger of the first aspect, wherein the flow passages are provided over the entire length of each honeycomb structure.

[0010] A third aspect of the present invention is the heat exchanger of the first or second aspect, wherein the cross-sectional area of ​​the flow passage at the upstream end of each honeycomb structure is larger than the cross-sectional area of ​​the flow passage at other portions of each honeycomb structure.

[0011] A fourth aspect of the present invention is the heat exchanger of the first or second aspect (or any one of the first to third aspects), in which the flow path includes a second fluid buffer section that integrally surrounds the upstream end or the downstream end of the heat exchange members and temporarily stores the second fluid. The second fluid is divided and supplied from the second fluid buffer section to the periphery of each of the heat exchange members.

[0012] A fifth aspect of the present invention is the heat exchanger of the first or second aspect (or any one of the first to fourth aspects), in which the flow paths include a front flow path that integrally surrounds the heat exchange members from one end in the axial direction to the center in the axial direction, and a rear flow path that is adjacent to the front flow path in the axial direction via a partition wall, integrally surrounds the heat exchange members from the other end in the axial direction to the center in the axial direction, and into which the second fluid flows from the front flow path via a communication port provided between the front flow path and the rear flow path. The communication port is provided at an end on one side in a predetermined direction perpendicular to the axial direction at the axial position where the partition wall is provided. The second fluid is supplied to the front flow path from the end of the front flow path on the other side in the predetermined direction. The second fluid is discharged to the outside of the rear flow path from the end of the rear flow path on the other side in the predetermined direction.

[0013] A sixth aspect of the present invention is the heat exchanger of the first or second aspect (which may be any one of the first to fifth aspects), further comprising a first fluid supply section disposed upstream of the plurality of heat exchange members and supplying the first fluid to the plurality of heat exchange members. The first fluid supply section comprises a first fluid buffer section which temporarily stores the first fluid and divides and supplies the first fluid to the plurality of heat exchange members. The flow path comprises an auxiliary flow path adjacent to the first fluid buffer section. Heat exchange is performed between the first fluid in the first fluid buffer section and the second fluid flowing through the auxiliary flow path.

[0014] A seventh aspect of the present invention is the heat exchanger of the sixth aspect, wherein the first fluid supply section further includes a first fluid supply pipe that supplies the first fluid to the first fluid buffer section, and the auxiliary flow path faces a supply port of the first fluid supply pipe in the axial direction across the first fluid buffer section.

[0015] Aspect 8 of the present invention is the heat exchanger of aspect 6 (which may be aspect 6 or 7), wherein the auxiliary flow path surrounds the periphery of the internal space of the first fluid buffer section.

[0016] A ninth aspect of the present invention is the heat exchanger of the first or second aspect (or any one of the first to eighth aspects), in which the cells of the honeycomb structure are circumferentially arranged along the inner peripheral surface of the outer peripheral wall, and the inner spaces of the cells are closed at the axial ends of the honeycomb structure.

[0017] A tenth aspect of the present invention is the heat exchanger of the first or second aspect (which may be any one of the first to ninth aspects), wherein the honeycomb structure of the plurality of heat exchange members is mainly made of ceramics. Effect of the Invention

[0018] According to the present invention, heat exchange between the first fluid and the second fluid can be efficiently performed while suppressing an increase in size of the heat exchange member. [Brief description of the drawings]

[0019] [Figure 1] FIG. 1 is a perspective view of a heat exchanger according to a first embodiment. [Diagram 2] FIG. [Diagram 3] FIG. [Figure 4] FIG. [Diagram 5] FIG. [Figure 6] FIG. 2 is a cross-sectional view showing a part of a heat exchanger. [Figure 7] FIG. 11 is a perspective view of a heat exchanger according to a second embodiment. [Figure 8] FIG. [Figure 9] FIG. [Figure 10] FIG. [Figure 11] FIG. [Figure 12] FIG. [Figure 13] FIG. [Figure 14] FIG. [Figure 15] FIG. 11 is a perspective view of a heat exchanger according to a third embodiment. [Figure 16] FIG. [Figure 17] FIG. [Figure 18] FIG. [Figure 19] FIG. 2 is a front view of the honeycomb structure. [Figure 20] 5A to 5C are schematic diagrams of a second fluid supply section, a second fluid discharge section, and a second flow path forming section. [Figure 21] 5A to 5C are schematic diagrams of a second fluid supply section, a second fluid discharge section, and a second flow path forming section. [Figure 22] 5A to 5C are schematic diagrams of a second fluid supply section, a second fluid discharge section, and a second flow path forming section. [Figure 23] 5A to 5C are schematic diagrams of a second fluid supply section, a second fluid discharge section, and a second flow path forming section. [Figure 24] 5A to 5C are schematic diagrams of a second fluid supply section, a second fluid discharge section, and a second flow path forming section. [Diagram 25] FIG. [Figure 26] FIG. [Figure 27] FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] FIG. 1 is a perspective view showing a heat exchanger 7 according to a first embodiment of the present invention. FIG. 2 is a front view of the heat exchanger 7 seen from the (-Y) side. FIG. 3 is a cross-sectional view of the heat exchanger 7 cut at the position III-III in FIG. 2. The heat exchanger 7 is mounted on an automobile, for example, and used to recover heat from exhaust gas from the automobile. The same applies to other heat exchangers described later. In FIGS. 1 to 3, three mutually orthogonal directions are indicated by arrows as the X direction, the Y direction, and the Z direction. The same applies to other drawings described later.

[0021] The heat exchanger 7 includes an outer wall portion 6 and a plurality of heat exchange members 5 housed inside the outer wall portion 6. In the example shown in Figs. 1 to 3, three substantially cylindrical heat exchange members 5 are housed inside the outer wall portion 6. The number of the plurality of heat exchange members 5 provided in the heat exchanger 7 may be changed in various ways as long as it is two or more. The arrangement of the plurality of heat exchange members 5 may also be changed as appropriate.

[0022] Fig. 4 is a perspective view showing one heat exchange member 5. Fig. 5 is a front view of the one heat exchange member 5 as viewed from the (-Y) side. The structures of the other heat exchange members 5 included in the heat exchanger 7 are substantially the same as the structures of the heat exchange members 5 shown in Figs. 4 and 5. Note that in Figs. 1 and 4, illustrations of cells 17 (described later) and the like on the end face on the (-Y) side of each heat exchange member 5 are omitted. The same applies to Figs. 7, 11, and 15 described later.

[0023] The heat exchange member 5 is a substantially cylindrical member centered on a central axis J1 extending parallel to the Y direction. In the following description, the Y direction in which the central axis J1 extends is also referred to as the “axial direction.” The heat exchange member 5 includes a honeycomb structure 1 and a covering portion 4.

[0024] The honeycomb structure 1 is a substantially cylindrical member extending substantially parallel to the Y direction about a central axis J1. The outer diameter of the honeycomb structure 1 (i.e., the diameter of a cross section perpendicular to the central axis J1) is substantially the same at any position in the Y direction. Inside the honeycomb structure 1, a plurality of cells 17 extending substantially parallel to the Y direction (i.e., the axial direction) are provided over the entire length of the honeycomb structure 1 in the Y direction. The cells 17 are flow paths through which a fluid such as a gas, liquid, or a gas-liquid two-phase fluid (hereinafter also referred to as a "first fluid") can pass. The first fluid is, for example, exhaust gas discharged from an automobile engine.

[0025] The honeycomb structure 1 is a member mainly composed of ceramics. This allows the thermal conductivity of the honeycomb structure 1 to be increased. From the viewpoint of increasing the thermal conductivity, it is preferable that the honeycomb structure 1 is formed of ceramics mainly composed of silicon carbide (SiC). In this specification, "mainly composed of ceramics" means that the ceramics are contained at 50 mass % or more. Furthermore, "ceramics mainly composed of SiC" means that the SiC content in the ceramics is 50 mass % or more.

[0026] From the viewpoint of further increasing the thermal conductivity, it is preferable that the honeycomb structure 1 is formed of ceramics mainly composed of SiC impregnated with metal Si. The thermal conductivity of the honeycomb structure 1 increases as the amount of metal Si impregnated increases. In this specification, "ceramics mainly composed of SiC impregnated with metal Si" means that the content of SiC impregnated with metal Si in the ceramics is 50 mass % or more.

[0027] The honeycomb structure 1 includes a cylindrical outer peripheral wall 11 and partition walls 18. In the example shown in Fig. 5, the outer peripheral wall 11 is a substantially cylindrical portion extending substantially parallel to the Y direction centered on the central axis J1. The length of the outer peripheral wall 11 in the Y direction is substantially the same as the overall length of the honeycomb structure 1 in the Y direction. The overall length of the honeycomb structure 1 in the Y direction is, for example, 1 mm to 500 mm.

[0028] The outer diameter and the inner diameter of the outer peripheral wall 11 are substantially the same at any position in the Y direction. The outer diameter of the outer peripheral wall 11 is substantially the same as the inner diameter of the covering portion 4. Before the honeycomb structure 1 is inserted inside the covering portion 4, the outer diameter of the outer peripheral wall 11 is preferably slightly (for example, 0.2 mm or more) larger than the inner diameter of the covering portion 4. The outer peripheral surface of the outer peripheral wall 11 contacts the inner peripheral surface of the covering portion 4 over substantially the entire surface. The inner diameter of the outer peripheral wall 11 is, for example, 30 mm to 300 mm. The thickness of the outer peripheral wall 11 in the radial direction (hereinafter, simply referred to as the "radial direction") centered on the central axis J1 is, for example, 0.2 mm to 2.0 mm. The internal space 100 of the outer peripheral wall 11 (i.e., the space radially inward from the inner peripheral surface of the outer peripheral wall 11) is a substantially cylindrical space extending substantially parallel to the Y direction centered on the central axis J1.

[0029] The partition walls 18 extend approximately parallel to the Y direction in the above-mentioned internal space 100, and divide the internal space 100 to form the above-mentioned multiple cells 17. The length of the partition walls 18 in the Y direction is approximately the same as the overall length of the honeycomb structure 1 in the Y direction. The length of the cells 17 in the Y direction is also approximately the same as the overall length of the honeycomb structure 1 in the Y direction. The shape of the partition walls 18 in a cross section perpendicular to the Y direction is approximately the same at any position in the Y direction. In the example shown in FIG. 5, the partition walls 18 in a cross section perpendicular to the Y direction include multiple partition wall elements concentrically arranged about the central axis J1, and multiple partition wall elements extending radially in the radial direction about the central axis J1.

[0030] The shape of each cell 17 in a cross section perpendicular to the Y direction (hereinafter simply referred to as the "cross-sectional shape") is approximately the same at any position in the Y direction. In the example shown in Fig. 5, the cross-sectional shape of the multiple cells 17 is approximately a sector shape centered on the central axis J1, or approximately a partial ring shape centered on the central axis J1 (i.e., a shape corresponding to a part of a ring).

[0031] The cells 17 are arranged concentrically about the central axis J1. The cells 17 arranged at the same radial position are arranged at approximately equal angular intervals in the circumferential direction (hereinafter also simply referred to as the "circumferential direction") about the central axis J1. The thickness of the partition walls 18 located between each two adjacent cells 17 in the circumferential direction is approximately the same as the thickness of the partition walls 18 located between each two adjacent cells 17 in the radial direction, and in the following description, these thicknesses are also simply referred to as the "thickness of the partition walls 18". The thickness of the partition walls 18 is, for example, 0.1 mm to 1.0 mm. The thickness of the partition walls 18 is, for example, thinner than the thickness of the outer peripheral wall 11.

[0032] The cell density of the cells 17 is, for example, 25 cpsi (cells / square inch) to 500 cpsi. The cell density is calculated by dividing the total number of the cells 17 in a front view by the area (square inches) of the region inside the inner peripheral surface of the outer peripheral wall 11.

[0033] The cell density of the cells 17 is not limited to the above range and may be changed as appropriate. The cross-sectional shape of the cells 17 is not limited to an approximately sector shape or an approximately partial ring shape and may be changed in various ways, such as an approximately square shape, an approximately rectangular shape, an approximately hexagonal shape, or an approximately circular shape. The arrangement of the cells 17 is not limited to the above example and may be changed in various ways. For example, a plurality of approximately square cells 17 partitioned by lattice-shaped partition walls in a front view may be arranged in a matrix shape at approximately equal intervals in the X direction and the Z direction. In this case, the cell density is calculated by a known method using the cell pitch, which is the center-to-center distance of adjacent cells 17 in a front view. For example, a tool microscope, a microscope, or the like is used to measure a predetermined number of cell pitches, and the arithmetic average of the predetermined number of cell pitches is calculated. The arithmetic average of the cell pitches is p (mm), and the cell density is (25.4 / p) 2 It is required as follows.

[0034] The covering portion 4 is a substantially cylindrical member extending substantially parallel to the Y direction centered on the central axis J1. The outer diameter of the covering portion 4 (i.e., the diameter of the outer peripheral surface in a cross section perpendicular to the Y direction) is substantially the same at any position in the Y direction. The inner diameter of the covering portion 4 (i.e., the diameter of the inner peripheral surface in a cross section perpendicular to the Y direction) is also substantially the same at any position in the Y direction. The inner diameter of the covering portion 4 is substantially the same as the outer diameter of the honeycomb structure 1. As described above, before the honeycomb structure 1 is inserted inside the covering portion 4, it is preferable that the outer diameter of the honeycomb structure 1 is slightly larger (e.g., by 0.2 mm or more) than the inner diameter of the covering portion 4.

[0035] In the example shown in FIG. 4, the length of the covering portion 4 in the Y direction is longer than the length of the honeycomb structure 1 in the Y direction. The covering portion 4 covers almost the entire outer peripheral surface of the honeycomb structure 1 from the end portion on the (-Y) side to the end portion on the (+Y) side of the honeycomb structure 1. The inner peripheral surface of the covering portion 4 is in direct contact with the outer peripheral surface of the honeycomb structure 1 over almost the entire surface. The inner peripheral surface of the covering portion 4 and the outer peripheral surface of the honeycomb structure 1 may be indirectly in contact with each other via an inclusion.

[0036] The opening on the (-Y) side of the covering portion 4 is located on the (-Y) side of the end face on the (-Y) side of the honeycomb structure 1. The opening on the (+Y) side of the covering portion 4 is located on the (+Y) side of the end face on the (+Y) side of the honeycomb structure 1. In other words, the covering portion 4 extends to the (-Y) side and the (+Y) side of the honeycomb structure 1.

[0037] The covering portion 4 is a member that is substantially impermeable to fluids such as gas, liquid, and gas-liquid two-phase fluid. Therefore, the first fluid flowing inside the honeycomb structure 1 (i.e., the plurality of cells 17) is prevented from permeating the covering portion 4 and leaking out from the outer peripheral surface of the covering portion 4 to the outside. The covering portion 4 is preferably formed of a metal (e.g., stainless steel) that has high heat resistance, thermal shock resistance, and corrosion resistance, and also has high thermal conductivity. Note that the covering portion 4 may be formed of a metal other than stainless steel, or may be formed of a material other than a metal.

[0038] 1, three heat exchange members 5 of substantially the same shape are arranged in parallel at substantially the same positions in the Y direction (i.e., the axial direction) and the Z direction. Specifically, the three heat exchange members 5 are arranged in parallel in the X direction at substantially the same positions in the Y direction and the Z direction such that the central axes J1 of the three heat exchange members 5 are substantially parallel to the Y direction. In addition, the (-Y) side ends of the three heat exchange members 5 are located at substantially the same positions in the Y direction, and the (+Y) side ends of the three heat exchange members 5 are also located at substantially the same positions in the Y direction.

[0039] The outer wall portion 6 includes a plurality of cylindrical second flow passage forming portions 61, two flange portions 62, a second fluid supply portion 63, and a second fluid discharge portion 64. Each portion of the outer wall portion 6 is formed of a metal such as stainless steel. This is the same for the other heat exchangers 7a and 7b described later. In the heat exchanger 7 illustrated in FIG. 1, three second flow passage forming portions 61 of substantially the same shape are arranged in parallel at substantially the same positions in the Y direction and the Z direction. One heat exchange member 5 is housed inside each second flow passage forming portion 61.

[0040] In the following, one set of second flow path forming portion 61 and heat exchange member 5 (i.e., one second flow path forming portion 61 and the heat exchange member 5 housed inside that one second flow path forming portion 61) will be described, but the same applies to other second flow path forming portions 61 and heat exchange members 5. In the example shown in FIG. 1, the second flow path forming portion 61 is a substantially cylindrical portion extending in the Y direction centered on the central axis J1 of the heat exchange member 5 housed therein. The length in the Y direction of the second flow path forming portion 61 is, for example, substantially the same as the length in the Y direction of the heat exchange member 5.

[0041] The inner diameter and the outer diameter of the second flow passage forming portion 61 are substantially the same at any position in the Y direction. The inner diameter of the second flow passage forming portion 61 is larger than the outer diameter of the covering portion 4 of the heat exchange member 5. The second flow passage forming portion 61 covers the outer peripheral surface of the covering portion 4 over substantially the entire circumference in the circumferential direction centered on the central axis J1, while being spaced radially outward from the outer peripheral surface of the covering portion 4. A substantially cylindrical space 70 is provided between the inner peripheral surface of the second flow passage forming portion 61 and the outer peripheral surface of the covering portion 4 (i.e., the outer peripheral surface of the heat exchange member 5), the space 70 being centered on the central axis J1 and extending substantially parallel to the Y direction.

[0042] The space 70 is a flow path for the second fluid, through which the second fluid having a temperature different from that of the first fluid flows, and is hereinafter also referred to as the "second flow path 70". The second fluid is a gas, a liquid, or a gas-liquid two-phase fluid. In this embodiment, the second fluid is a fluid having a lower temperature than the first fluid, for example, liquid water. The length of the second flow path 70 in the Y direction is, for example, approximately the same as the length of the heat exchange member 5 in the Y direction. In FIG. 3, the second fluid flowing in the second flow path 70 is marked with parallel diagonal lines to facilitate understanding of the drawing. The honeycomb structure 1 is also marked with parallel diagonal lines. The same applies to FIGS. 6, 9, 10, 12 to 14, and 17 described later.

[0043] Each of the two flange portions 62 is a substantially flat plate-shaped portion substantially perpendicular to the Y direction. The flange portion 62 on the (-Y) side connects the (-Y) side ends of the three second flow path forming portions 61 aligned in the X direction. The flange portion 62 on the (+Y) side connects the (+Y) side ends of the three second flow path forming portions 61 aligned in the X direction. Each flange portion 62 is provided with three openings corresponding to the end openings of the three second flow path forming portions 61.

[0044] The second fluid supply unit 63 is a pipe extending approximately parallel to the X direction near the end of the three second flow path forming parts 61 on the (+Y) side. The second fluid supply unit 63 is disposed on the (+Z) side of the three second flow path forming parts 61, and is connected to the three second flow path forming parts 61 individually. The second fluid discharge unit 64 is a pipe extending approximately parallel to the X direction near the end of the three second flow path forming parts 61 on the (-Y) side. The second fluid discharge unit 64 is disposed on the (-Z) side of the three second flow path forming parts 61, and is connected to the three second flow path forming parts 61 individually. The second fluid supply unit 63 supplies the second fluid to the three second flow paths 70. The second fluid flows in the (-Y) direction in each second flow path 70 while filling each second flow path 70, and is discharged to the outside of the heat exchanger 7 via the second fluid discharge unit 64.

[0045] 3, the second flow passage forming portion 61 and the second flow passage 70 extend from one of the two flange portions 62 to the other. That is, the second flow passage 70 is provided over substantially the entire length of the heat exchange member 5 in the Y direction. Therefore, the second flow passage 70 is provided over substantially the entire length of the honeycomb structure 1 in the Y direction. The second flow passage 70 covers the outer peripheral surface of the heat exchange member 5 on the radial outside of the heat exchange member 5 over the entire circumference in the circumferential direction.

[0046] FIG. 6 is an enlarged view of a part of the end portion on the (-Y) side of the heat exchanger 7 shown in FIG. 3. As shown in FIG. 6, a flow passage expansion section 73 is provided at the end portion on the (-Y) side of each second flow passage 70. The flow passage expansion section 73 is a part of the second flow passage 70, and has a radial width larger than other parts of the second flow passage 70 (i.e., parts other than the flow passage expansion section 73). In other words, the cross-sectional area of ​​the flow passage expansion section 73 (i.e., the area of ​​a cross section perpendicular to the Y direction) is larger than the cross-sectional area of ​​other parts of the second flow passage 70. The flow passage expansion section 73 is a substantially cylindrical space extending in the Y direction with the central axis J1 as the center. The inner diameter and the outer diameter of the second flow passage formation section 61 in the flow passage expansion section 73 are larger than the inner diameter and the outer diameter of the second flow passage formation section 61 in other parts of the second flow passage 70, respectively.

[0047] The radial width of the expanded flow path section 73 is, for example, 1.2 to 3 times the radial width of other parts of the second flow path 70. The length in the Y direction of the expanded flow path section 73 is, for example, 5% to 20% of the entire length in the Y direction of the second flow path 70. The size of the expanded flow path section 73 in the second flow path 70 may be changed as appropriate.

[0048] In the heat exchanger 7 shown in Figs. 1 to 3, the first fluid flows into the three heat exchange members 5 through the three openings of the flange portion 62 on the (-Y) side, and is supplied to the honeycomb structure 1 of each heat exchange member 5 from the (-Y) side. The first fluid flows into the cells 17 of the honeycomb structure 1, and flows from the (-Y) side (hereinafter also referred to as the "upstream side"), which is one side in the axial direction of each cell 17, to the (+Y) side (hereinafter also referred to as the "downstream side"), which is the other side in the axial direction. The first fluid that has passed through the cells 17 of the three heat exchange members 5 flows out of the heat exchanger 7 through the three openings of the flange portion 62 on the (+Y) side. In the following description, the "upstream side" and the "downstream side" respectively mean the upstream side and the downstream side in the flow direction of the first fluid, as in the above.

[0049] In the heat exchanger 7, heat exchange is performed between the first fluid flowing inside each heat exchange member 5 and the second fluid flowing through the second flow path 70 around each heat exchange member 5 via the heat exchange member 5. Specifically, the honeycomb structure 1 and the covering portion 4 are heated by the high-temperature first fluid flowing through the multiple cells 17. Then, the low-temperature second fluid flowing through the second flow path 70 while in contact with the covering portion 4 is heated. Meanwhile, the temperature of the first fluid is reduced by passing through the heat exchange member 5. Note that since the covering portion 4 is a member that is impermeable to the first and second fluids, the first fluid flowing inside the heat exchange member 5 does not leak into the second flow path 70, and the second fluid flowing through the second flow path 70 does not leak into the heat exchange member 5.

[0050] As described above, the heat exchanger 7 includes a plurality of heat exchange members 5 and an outer wall portion 6. Each of the plurality of heat exchange members 5 is a structure in which the outer peripheral surface of the honeycomb structure 1 is covered with a cylindrical covering portion 4. The honeycomb structure 1 has a cylindrical outer peripheral wall 11 and partition walls 18 that partition the internal space 100 of the outer peripheral wall 11 and extend in the axial direction (Y direction in the above example). The partition walls 18 form a plurality of cells 17 through which a first fluid flows. The plurality of heat exchange members 5 are arranged in parallel at the same position in the axial direction. The outer wall portion 6 covers the outer peripheral surfaces of the plurality of heat exchange members 5 while being spaced outward from the outer peripheral surfaces of the plurality of heat exchange members 5, thereby forming a flow path (i.e., a second flow path 70) through which a second fluid that exchanges heat with the first fluid flows between the outer peripheral surfaces of the plurality of heat exchange members 5 and the outer peripheral surfaces of the plurality of heat exchange members 5.

[0051] In this way, in the heat exchanger 7, by arranging a plurality of heat exchange members 5 in parallel, it is possible to suppress an increase in size of the honeycomb structure 1 provided in each heat exchange member 5. This makes it possible to suppress a decrease in the amount of heat recovered per unit volume that occurs when the diameter or axial length of the honeycomb structure 1 is increased. That is, in the heat exchanger 7, it is possible to efficiently perform heat exchange between the first fluid and the second fluid while suppressing an increase in size of the heat exchange members 5.

[0052] As described above, the second flow paths 70 are preferably provided over the entire length of each honeycomb structure 1. This makes it possible to increase the contact area in the indirect contact between the second fluid and each honeycomb structure 1 via the covering portion 4. As a result, heat exchange between the first fluid flowing inside the honeycomb structure 1 and the second fluid flowing through the second flow paths 70 can be performed more efficiently.

[0053] As described above, it is preferable that the cross-sectional area of ​​the second flow passage 70 at the upstream end of each honeycomb structure 1 (in the above example, the flow passage enlarged portion 73 which is the end on the (-Y) side) is larger than the cross-sectional area of ​​the second flow passage 70 at other portions of each honeycomb structure 1. This makes it possible to increase the amount of the second fluid exchanging heat with the first fluid on the upstream side of the honeycomb structure 1 where there is little temperature change (temperature drop in the above example) of the first fluid due to contact with the honeycomb structure 1. As a result, heat exchange between the first fluid and the second fluid can be performed more efficiently.

[0054] As described above, it is preferable that the honeycomb structure 1 of the plurality of heat exchange members 5 is mainly composed of ceramics. This can improve the heat resistance, thermal shock resistance, and corrosion resistance of the honeycomb structure 1 compared to the case where the honeycomb structure 1 is mainly composed of other components such as metal.

[0055] Next, a heat exchanger 7a according to a second embodiment of the present invention will be described. Fig. 7 is a perspective view showing the heat exchanger 7a. Fig. 8 is a front view of the heat exchanger 7a seen from the (-Y) side. Fig. 9 is a cross-sectional view of the heat exchanger 7a taken along line IX-IX in Fig. 8. Fig. 10 is a cross-sectional view of the heat exchanger 7a taken along line XX in Fig. 8.

[0056] The heat exchanger 7a includes an outer wall portion 6a and a plurality of heat exchange members 5 housed inside the outer wall portion 6a. Each of the plurality of heat exchange members 5 has substantially the same shape as the heat exchange member 5 (see Figs. 4 and 5) provided in the above-mentioned heat exchanger 7. In the example shown in Figs. 7 to 10, four substantially cylindrical heat exchange members 5 are housed inside the outer wall portion 6a.

[0057] The four heat exchange members 5 are arranged in parallel at approximately the same position in the Y direction (i.e., the axial direction). Specifically, the four heat exchange members 5 are arranged in parallel to each other at approximately the same position in the Y direction in the X direction and the Z direction so that the central axes J1 of the four heat exchange members 5 are approximately parallel to the Y direction. Of the four heat exchange members 5, the two heat exchange members 5 on the (+Z) side are arranged in parallel in the X direction at approximately the same positions in the Y direction and the Z direction. Of the four heat exchange members 5, the other two heat exchange members 5 are arranged in parallel in the X direction at approximately the same positions in the Y direction and the Z direction on the (-Z) side of the above two heat exchange members 5. The two heat exchange members 5 on the upper stage (i.e., the (+Z) side) are each located at approximately the same position in the X direction as the other two heat exchange members 5 on the lower stage (i.e., the (-Z) side). The number and arrangement of the multiple heat exchange members 5 provided in the heat exchanger 7a may be changed as appropriate.

[0058] The outer wall portion 6a includes a second flow path forming portion 61a, a second fluid supply portion 63a, and a second fluid discharge portion 64a. The second flow path forming portion 61a includes a plurality of (four in the above example) cylindrical pipe line forming portions 65a and two buffer forming portions 66a.

[0059] Each buffer forming portion 66a is a hollow, substantially rectangular parallelepiped portion. The (-Y) side buffer forming portion 66a of the two buffer forming portions 66a accommodates the (-Y) side ends of the four heat exchange members 5 therein. The (-Y) side side of the (-Y) side buffer forming portion 66a has four openings corresponding to the end openings of the four heat exchange members 5. The (+Y) side buffer forming portion 66a of the two buffer forming portions 66a accommodates the (+Y) side ends of the four heat exchange members 5 therein. The (+Y) side side of the (+Y) side buffer forming portion 66a has four openings corresponding to the end openings of the four heat exchange members 5. Each buffer forming portion 66a connects the ends of the four heat exchange members 5. The inner side of each buffer forming portion 66a is spaced apart from the outer circumferential surfaces of the four heat exchange members 5.

[0060] The four pipe line forming portions 65a are disposed between the two buffer forming portions 66a in the Y direction, and each of them accommodates a heat exchange member 5 therein. Each pipe line forming portion 65a is a substantially cylindrical portion extending in the Y direction centered on the central axis J1 of the heat exchange member 5 accommodated therein. The length of the pipe line forming portion 65a in the Y direction is shorter than the length of the heat exchange member 5 in the Y direction. The (-Y) side end of the pipe line forming portion 65a is connected to the (+Y) side surface of the (-Y) side buffer forming portion 66a. The (+Y) side end of the pipe line forming portion 65a is connected to the (-Y) side surface of the (+Y) side buffer forming portion 66a.

[0061] The conduit forming portion 65a covers the heat exchange member 5 at a portion other than both ends in the Y direction (hereinafter, also referred to as the "center portion of the heat exchange member 5") from the radially outer side over substantially the entire circumference in the circumferential direction centered on the central axis J1 of the heat exchange member 5. The inner diameter and the outer diameter of the conduit forming portion 65a are substantially the same at any position in the Y direction. The inner diameter of the conduit forming portion 65a is larger than the outer diameter of the covering portion 4 of the heat exchange member 5. The conduit forming portion 65a covers the outer peripheral surface of the covering portion 4 while being spaced radially outward from the outer peripheral surface of the covering portion 4. Between the inner peripheral surface of each conduit forming portion 65a and the outer peripheral surface of the covering portion 4 (i.e., the outer peripheral surface of the heat exchange member 5), a substantially cylindrical space 71a is provided that extends substantially parallel to the Y direction centered on the central axis J1. The four spaces 71a communicate with the spaces 72a inside the two buffer forming portions 66a.

[0062] The space 72a inside each buffer forming portion 66a is a single space that spreads around the ends of the four heat exchange members 5, and the cross section perpendicular to the Y direction is a continuous region. In each space 72a, the ends of the four heat exchange members 5 are disposed spaced apart from one another.

[0063] The four spaces 71a and the two spaces 72a are flow paths for the second fluid, through which the second fluid, which has a temperature different from that of the first fluid, flows. In the following description, the four spaces 71a and the two spaces 72a are collectively referred to as the "second flow path 70a". Each space 71 is also referred to as the "second intermediate flow path 71a", and each space 72a is also referred to as the "second fluid buffer section 72a". Each second fluid buffer section 72a integrally surrounds the ends of the four heat exchange members 5 in the Y direction. In each second fluid buffer section 72a, the outer peripheral surface of the end of each heat exchange member 5 contacts the second fluid over substantially the entire circumference. Each second intermediate flow path 71a covers the outer peripheral surface of the center part of the heat exchange member 5 over the entire circumference in the circumferential direction between the two second fluid buffer sections 72a.

[0064] The second fluid supply unit 63a is connected to the (+Y) side buffer forming unit 66a. The second fluid discharge unit 64a is connected to the (-Y) side buffer forming unit 66a. In the example shown in FIG. 7, the second fluid supply unit 63a is a conduit connected to the (+Z) side of the (+Y) side buffer forming unit 66a. Also, the second fluid discharge unit 64a is a conduit connected to the (-Z) side of the (-Y) side buffer forming unit 66a.

[0065] The second fluid supply unit 63a supplies the second fluid to the second fluid buffer unit 72a on the (+Y) side. The second fluid fills the second fluid buffer unit 72a and is temporarily stored in the second fluid buffer unit 72a. The second fluid is divided and supplied from the second fluid buffer unit 72a to the four second intermediate flow paths 71a provided around the four heat exchange members 5, respectively. As a result, the second fluid is supplied approximately evenly to the four second intermediate flow paths 71a.

[0066] The second fluid, filling each of the second intermediate flow paths 71a, flows in the (-Y) direction within each of the second intermediate flow paths 71a and flows into the (-Y) side second fluid buffer portion 72a where it is temporarily stored. The second fluid within the (-Y) side second fluid buffer portion 72a is discharged to the outside of the heat exchanger 7a via the second fluid discharge portion 64a.

[0067] In the heat exchanger 7a, the second fluid supply unit 63a may be connected to the buffer forming unit 66a on the (-Y) side, and the second fluid discharge unit 64a may be connected to the buffer forming unit 66a on the (+Y) side. That is, the second fluid supply unit 63a supplies the second fluid to one of the second fluid buffer units 72a on the upstream and downstream sides, and the second fluid discharge unit 64a discharges the second fluid from the other second fluid buffer unit 72a to the outside.

[0068] The heat exchanger 7a may further include a first fluid supply unit 53a and a first fluid discharge unit 54a, as shown in Figures 11 to 13. Figure 11 is a perspective view of the heat exchanger 7a provided with the first fluid supply unit 53a and the first fluid discharge unit 54a. Figures 12 and 13 are cross-sectional views of the heat exchanger 7a provided with the first fluid supply unit 53a and the first fluid discharge unit 54a, at positions corresponding to those of Figures 9 and 10 described above.

[0069] 11 to 13, the first fluid supply unit 53a is disposed adjacent to the upstream side (i.e., the (-Y) side) of the second fluid buffer unit 72a on the (-Y) side of the two second fluid buffer units 72a. In other words, the first fluid supply unit 53a is disposed upstream of the multiple heat exchange members 5.

[0070] The first fluid supply section 53a includes a first fluid buffer section 56a and a first fluid supply pipe 57a. The first fluid buffer section 56a collectively covers the (-Y) side end faces of the four heat exchange members 5 and the (-Y) side surface of the (-Y) side buffer forming section 66a from the (-Y) side. In the example shown in FIG. 11, the first fluid buffer section 56a is a hollow, substantially quadrangular pyramid-shaped section whose cross-sectional area gradually decreases toward the (-Y) direction. The (+Y) side end of the first fluid buffer section 56a opens in a substantially square shape. The (+Y) side edge of the first fluid buffer section 56a is connected to the outer periphery of the (-Y) side buffer forming section 66a over the entire circumference.

[0071] The first fluid supply pipe 57a is a pipe connected to an end portion on the (-Y) side of the first fluid buffer portion 56a, and guides the first fluid to the first fluid buffer portion 56a. In the example shown in Fig. 11, the first fluid supply pipe 57a is a substantially cylindrical pipe extending in the Y direction centered on a central axis J2 extending parallel to the Y direction. The central axis J2 passes through substantially the center of the two buffer forming portions 66a described above in a front view.

[0072] The first fluid discharge section 54a discharges the first fluid discharged from the heat exchange members 5 to the outside of the heat exchanger 7a. In the example shown in FIG. 11 to FIG. 13, the first fluid discharge section 54a is disposed adjacent to the downstream side (i.e., the (+Y) side) of the second fluid buffer section 72a on the (+Y) side of the two second fluid buffer sections 72a. In other words, the first fluid discharge section 54a is disposed on the downstream side of the heat exchange members 5. The first fluid discharge section 54a has substantially the same shape as the first fluid supply section 53a except that it faces the opposite side in the Y direction. In other words, the first fluid discharge section 54a is a portion that is substantially symmetrical to the first fluid supply section 53a with respect to a virtual plane perpendicular to the Y direction.

[0073] 11, the first fluid is supplied to the first fluid buffer section 56a via the first fluid supply pipe 57a of the first fluid supply section 53a, and is temporarily stored inside the first fluid buffer section 56a. The first fluid stored inside the first fluid buffer section 56a is divided and supplied to the multiple heat exchange members 5, and passes through each heat exchange member 5 from the (-Y) side to the (+Y) side. The first fluid that has passed through the multiple heat exchange members 5 is discharged to the outside of the heat exchanger 7a via the first fluid discharge section 54a.

[0074] In the heat exchanger 7a, heat exchange is performed between the first fluid flowing from the first fluid buffer portion 56a into the inside of the heat exchange members 5 and the second fluid in the second fluid buffer portion 72a surrounding the (-Y) side end of the heat exchange members 5, via the heat exchange members 5. In addition, heat exchange is performed between the first fluid flowing inside the heat exchange members 5 at the center of each heat exchange member 5 and the second fluid flowing through the second intermediate flow path 71a surrounding the periphery of the center of the heat exchange member 5, via the heat exchange members 5. In addition, heat exchange is performed between the first fluid flowing inside the heat exchange members 5 at the (+Y) side end of each heat exchange member 5 and the second fluid in the second fluid buffer portion 72a surrounding the (+Y) side end of the heat exchange members 5, via the heat exchange members 5. In the heat exchanger 7a, similarly to the above-mentioned heat exchanger 7, the heat exchange between the first fluid and the second fluid can be efficiently performed while suppressing the increase in size of the heat exchange members 5.

[0075] In the heat exchanger 7a, the second fluid flowing through the second fluid buffer section 72a on the (-Y) side of the second flow path 70a indirectly contacts the first fluid in the first fluid buffer section 56a through the (-Y) side of the buffer forming section 66a on the (-Y) side. Therefore, heat exchange is performed between the first fluid in the first fluid buffer section 56a and the second fluid flowing through the second fluid buffer section 72a through the side of the buffer forming section 66a without the heat exchange member 5. In other words, the second fluid buffer section 72a on the (-Y) side is adjacent to the first fluid buffer section 56a and is an auxiliary flow path that performs auxiliary heat exchange upstream of the heat exchange through the heat exchange member 5.

[0076] Furthermore, a portion of the (-Y) side second fluid buffer portion 72a near the central axis J2 (hereinafter also referred to as "the central portion of the second fluid buffer portion 72a") faces the supply port of the first fluid supply pipe 57a in the Y direction, across the (-Y) side surface of the buffer forming portion 66a and the first fluid buffer portion 56a. Therefore, the first fluid of relatively high temperature supplied from the first fluid supply pipe 57a into the first fluid buffer portion 56a is sprayed directly toward the central portion of the second fluid buffer portion 72a.

[0077] Specifically, the first fluid supplied from the first fluid supply pipe 57a into the first fluid buffer section 56a is sprayed onto a portion of the side surface on the (-Y) side of the buffer forming section 66a that is located between the center of the second fluid buffer section 72a and the first fluid buffer section 56a (hereinafter, also referred to as the "center of the side surface of the buffer forming section 66a"). The center of the side surface of the buffer forming section 66a is approximately perpendicular to the flow direction of the first fluid supplied from the first fluid supply section 53a. Therefore, the efficiency of heat exchange between the second fluid in the center of the second fluid buffer section 72a and the first fluid in the first fluid buffer section 56a is improved.

[0078] As described above, in the heat exchanger 7a, the second flow path 70a includes the second fluid buffer section 72a that temporarily stores the second fluid. The second fluid buffer section 72a integrally surrounds the upstream end or downstream end (in the above example, the (-Y) side or (+Y) side end) of the multiple heat exchange members 5. The second fluid is divided and supplied from the second fluid buffer section 72a (in the example shown in FIG. 7, the (+Y) side second fluid buffer section 72a) to the periphery of each of the multiple heat exchange members 5 (i.e., the second intermediate flow path 71a). This allows the second fluid to be supplied approximately evenly to the multiple heat exchange members 5. As a result, the heat exchange between the first fluid and the second fluid can be performed approximately evenly in the multiple heat exchange members 5, and the efficiency of heat exchange in the heat exchanger 7a can be improved.

[0079] As described above, the heat exchanger 7a further includes a first fluid supply unit 53a. The first fluid supply unit 53a is disposed on the upstream side (the (-Y) side in the above example) of the plurality of heat exchange members 5, and supplies the first fluid to the plurality of heat exchange members 5. The first fluid supply unit 53a includes a first fluid buffer unit 56a that temporarily stores the first fluid and divides and supplies the first fluid to the plurality of heat exchange members 5. The second flow path 70a includes an auxiliary flow path adjacent to the first fluid buffer unit 56a (the second fluid buffer unit 72a on the (-Y) side in the above example). Then, heat exchange is performed between the first fluid in the first fluid buffer unit 56a and the second fluid flowing through the auxiliary flow path. This can improve the efficiency of heat exchange between the first fluid and the second fluid, as described above.

[0080] As described above, the first fluid supply section 53a further includes a first fluid supply pipe 57a that supplies the first fluid to the first fluid buffer section 56a. Preferably, the auxiliary flow path faces the supply port of the first fluid supply pipe 57a in the axial direction (Y direction in the above example) across the first fluid buffer section 56a. This can further improve the efficiency of heat exchange between the first fluid and the second fluid, as described above.

[0081] More preferably, the wall surface located between the center of the auxiliary flow path and the first fluid buffer section 56a (i.e., the center of the side surface on the (-Y) side of the buffer forming section 66a) is perpendicular to the flow direction of the first fluid supplied from the first fluid supply section 53a. This can further improve the efficiency of heat exchange between the first fluid supplied from the first fluid supply section 53a and the second fluid flowing through the auxiliary flow path.

[0082] In the example shown in Figs. 11 to 13, the entire second fluid buffer section 72a on the (-Y) side, which is the auxiliary flow path, is disposed on the (+Y) side of the end portion on the (+Y) side of the first fluid buffer section 56a, but the arrangement of the auxiliary flow path is not limited to this. For example, as shown in Fig. 14, the second fluid buffer section 72a on the (-Y) side may be provided with a protruding section 721a that protrudes in the (-Y) direction toward the inside of the first fluid buffer section 56a. The protruding section 721a, which is a part of the auxiliary flow path, surrounds, for example, the (+Y) side region of the internal space of the first fluid buffer section 56a from the outer side in the radial direction centered on the central axis J2 to approximately the entire circumference in the circumferential direction centered on the central axis J2. Heat exchange is also performed between the second fluid flowing through the protruding section 721a and the first fluid in the first fluid buffer section 56a, so that heat exchange between the first fluid and the second fluid can be performed more efficiently.

[0083] Next, a heat exchanger 7b according to a third embodiment of the present invention will be described. Fig. 15 is a perspective view showing the heat exchanger 7b. Fig. 16 is a front view of the heat exchanger 7b seen from the (-Y) side. Fig. 17 is a cross-sectional view of the heat exchanger 7b taken along line XVII-XVII in Fig. 16. Fig. 18 is a cross-sectional view of the heat exchanger 7b taken along line XVIII-XVIII in Fig. 17. In Fig. 18, a partition wall 67b, which will be described later, is marked with parallel diagonal lines to facilitate understanding of the figure.

[0084] The heat exchanger 7b includes an outer wall portion 6b and a plurality of heat exchange members 5 housed inside the outer wall portion 6b. In the example shown in Fig. 15 to Fig. 18, four heat exchange members 5 similar to those of the above-mentioned heat exchanger 7a are arranged in parallel at substantially the same positions in the Y direction (i.e., the axial direction) in substantially the same manner as the heat exchanger 7a. The number and arrangement of the plurality of heat exchange members 5 provided in the heat exchanger 7b may be changed as appropriate.

[0085] The outer wall portion 6b is a hollow member having a substantially rectangular parallelepiped shape. The shape of the outer wall portion 6b in a front view is substantially the same as the shape of the buffer forming portion 66a (see FIG. 8) of the above-mentioned heat exchanger 7a in a front view. The length of the outer wall portion 6b in the Y direction is substantially the same as the length of the heat exchange member 5 in the Y direction. The outer wall portion 6b accommodates substantially the entirety of the four heat exchange members 5 inside. Four openings corresponding to the end openings on the (-Y) side and the (+Y) side of the outer wall portion 6b are provided on the (-Y) side and the (+Y) side, respectively. The inner surface of the outer wall portion 6b is spaced apart from the outer peripheral surfaces of the four heat exchange members 5.

[0086] A partition wall 67b is provided inside the outer wall portion 6b. The partition wall 67b is a substantially flat plate-shaped member substantially perpendicular to the Y direction. The partition wall 67b is made of a material that is impermeable to the above-mentioned second fluid. The partition wall 67b is made of a metal such as stainless steel, for example, like the outer wall portion 6b. The partition wall 67b is located at a position shown in FIG. 18 in the Y direction (i.e., substantially at the center of the outer wall portion 6b in the Y direction) and divides the internal space of the outer wall portion 6b into two parts, the (-Y) side and the (+Y) side. As shown in FIG. 18, the outer peripheral edge of the partition wall 67b is connected to the inner surface of the outer wall portion 6b over substantially the entire length of the region excluding the end portion on the (+Z) side of the inner surface of the outer wall portion 6b.

[0087] The partition wall 67b is connected to the outer circumferential surface of each heat exchange member 5 at the approximate center in the Y direction of each heat exchange member 5. Specifically, for two heat exchange members 5 on the (-Z) side among the four heat exchange members 5, the partition wall 67b is connected to the outer circumferential surfaces of the two heat exchange members 5 over approximately the entire circumference in the circumferential direction (i.e., the circumferential direction centered on the central axis J1). Also, for two heat exchange members 5 on the (+Z) side, the partition wall 67b is connected to approximately the lower half of the outer circumferential surfaces of the two heat exchange members 5 that are located on the (-Z) side of the central axis J1. The connection portion between the partition wall 67b and each heat exchange member 5 and the connection portion between the partition wall 67b and the inner surface of the outer wall portion 6b are airtight and liquidtight.

[0088] The internal space of the outer wall portion 6b is a second flow path 70b in which the second fluid flows around the four heat exchange members 5. In the following description, within the internal space of the outer wall portion 6b (i.e., the second flow path 70b), the space on the (+Y) side of the position where the partition wall 67b is provided is also referred to as the "front flow path 75b," and the space on the (-Y) side of the position where the partition wall 67b is provided is also referred to as the "rear flow path 76b." The front flow path 75b and the rear flow path 76b are adjacent to each other in the Y direction with the partition wall 67b in between.

[0089] The front flow paths 75b integrally surround a portion of each heat exchange member 5 from the end on the (+Y) side to the center in the Y direction (hereinafter also referred to as the "front portion of the heat exchange member 5"). The rear flow paths 76b integrally surround a portion of each heat exchange member 5 from the end on the (-Y) side to the center in the Y direction (hereinafter also referred to as the "rear portion of the heat exchange member 5").

[0090] In the internal space of the outer wall 6b, at the position in the Y direction where the partition wall 67b is provided, the region on the (+Z) side of the (+Z) side edge of the partition wall 67b is a communication port 77b through which the front flow path 75b and the rear flow path 76b communicate with each other. The communication port 77b is an opening that is substantially rectangular in front view and is surrounded by the (+Z) side edge of the partition wall 67b and the inner surface of the outer wall 6b. Note that the communication port 77b does not necessarily need to be surrounded by the edge of the partition wall 67b and the inner surface of the outer wall 6b, and may be, for example, a through hole that penetrates the partition wall 67b in the Y direction. The shape of the communication port 77b in front view is not limited to a substantially rectangular shape and may be variously changed.

[0091] In the heat exchanger 7b illustrated in FIG. 15, the second fluid supply unit 63b and the second fluid discharge unit 64b are connected to the (-Z) side surface of the outer wall unit 6b. The second fluid supply unit 63b is connected to the front flow path 75b on the (+Y) side of the partition wall 67b, and supplies the second fluid to the front flow path 75b from the (-Z) side. The second fluid supplied from the second fluid supply unit 63b flows through the front flow path 75b from the (-Z) side to the (+Z) side, and flows into the rear flow path 76b through the communication port 77b located at the end of the (+Z) side. The second fluid discharge unit 64b is connected to the rear flow path 76b on the (-Y) side of the partition wall 67b, and discharges the second fluid flowing through the rear flow path 76b from the (+Z) side to the (-Z) side to the outside of the rear flow path 76b. In the second flow paths 70b, the outer circumferential surface of each heat exchange member 5 comes into contact with the second fluid over substantially the entire length and substantially the entire periphery.

[0092] In the heat exchanger 7b, the arrangement of the communication port 77b, the second fluid supply unit 63b, and the second fluid discharge unit 64b is not limited to the above example, as long as the communication port 77b is arranged at an end on one side in a predetermined direction perpendicular to the Y direction, and the second fluid supply unit 63b and the second fluid discharge unit 64b are arranged at an end on the other side in the predetermined direction. For example, the communication port 77b may be provided at an end on the (+X) side of the partition wall 67b. In this case, the second fluid supply unit 63b is connected to a portion on the (-X) side of the outer wall 6b, and supplies the second fluid to the front flow path 75b from the end on the (-X) side of the front flow path 75b. The second fluid discharge unit 64b is connected to a portion on the (-X) side of the outer wall 6b, and discharges the second fluid from the end on the (-X) side of the rear flow path 76b to the outside of the rear flow path 76b.

[0093] As described above, in the heat exchanger 7b, the second flow path 70b includes the front flow path 75b and the rear flow path 76b. The front flow path 75b integrally surrounds the heat exchange members 5 from the end on one axial side (in the above example, the (+Y) side) to the center in the axial direction. The rear flow path 76b is adjacent to the front flow path 75b in the axial direction via the partition wall 67b. The rear flow path 76b integrally surrounds the heat exchange members 5 from the end on the other axial side (in the above example, the (-Y) side) to the center in the axial direction. The second fluid flows into the rear flow path 76b from the front flow path 75b through a communication port 77b provided between the front flow path 75b and the rear flow path 76b. The communication port 77b is provided at an end on one side in a predetermined direction perpendicular to the axial direction (in the above example, the (+Z) side) at an axial position where the partition wall 67b is provided. The second fluid is supplied to the front flow passage 75b from the other end of the front flow passage 75b in the predetermined direction (the (-Z) side in the above example). The second fluid is discharged to the outside of the rear flow passage 76b from the other end of the rear flow passage 76b in the predetermined direction.

[0094] This allows the cross section of the second flow passage 70b perpendicular to the direction in which the second fluid flows to be relatively large at each position of the second flow passage 70b. This reduces the pressure loss of the second fluid in the second flow passage 70b and increases the flow rate of the second fluid. As a result, the efficiency of heat exchange between the first fluid and the second fluid in the heat exchanger 7b can be improved. In addition, the shape of the outer wall portion 6b can be simplified, making it easier to manufacture the heat exchanger 7b.

[0095] 11 to 13, the heat exchanger 7b may have a first fluid supply section 53a provided on the (-Y) side of the heat exchanger 7b and a first fluid discharge section 54a provided on the (+Y) side of the heat exchanger 7b. In this case, the rear flow path 76b serves as the above-mentioned auxiliary flow path, and heat exchange is performed between the second fluid flowing through the rear flow path 76b and the first fluid in the first fluid buffer section 56a (see FIG. 11) without passing through the heat exchange member 5. As a result, the efficiency of heat exchange between the first fluid and the second fluid can be further improved, similarly to the above-mentioned heat exchanger 7a.

[0096] In the above-described heat exchangers 7, 7a, and 7b, heat exchange members having various other structures may be provided instead of the heat exchange member 5 shown in Fig. 4 and Fig. 5. For example, as shown in the front view of Fig. 19, a heat exchange member 5c in which no cells 17 are provided in the vicinity of the central axis J1 may be used. The heat exchange member 5c includes a honeycomb structure 1c having a different structure from the honeycomb structure 1 shown in Fig. 5.

[0097] In the honeycomb structure 1c, a cylindrical inner peripheral wall 12 is provided radially inside the outer peripheral wall 11 of the honeycomb structure 1 shown in FIG. 5. In the example shown in FIG. 19, the inner peripheral wall 12 is a substantially cylindrical portion extending substantially parallel to the Y direction centered on the central axis J1. The length of the inner peripheral wall 12 in the Y direction is substantially the same as the overall length of the honeycomb structure 1c in the Y direction. The ratio of the inner diameter of the inner peripheral wall 12 to the inner diameter of the outer peripheral wall 11 is, for example, 45% to 90%. The radial thickness of the inner peripheral wall 12 is, for example, substantially the same as the radial thickness of the outer peripheral wall 11. The outer peripheral wall 11 and the inner peripheral wall 12 are connected by partition walls 18.

[0098] In the following description, the region between the outer peripheral wall 11 and the inner peripheral wall 12 in the internal space 100 of the outer peripheral wall 11 is referred to as the "outer region 101", and the region radially inward of the inner peripheral wall 12 is referred to as the "inner region 102". The outer region 101 is a substantially cylindrical space extending approximately parallel to the Y direction centered on the central axis J1. The inner region 102 is a substantially cylindrical space extending approximately parallel to the Y direction centered on the central axis J1. The inner region 102 is a region located radially inward of the outer region 101 and surrounded by the outer region 101 over the entire circumference in the circumferential direction.

[0099] In the outer region 101, a plurality of cells 17 are arranged circumferentially along the inner peripheral surface of the outer peripheral wall 11 and the outer peripheral surface of the inner peripheral wall 12, in a manner similar to that of the honeycomb structure 1 shown in Fig. 5. The inner region 102 (i.e., the space radially inside the plurality of cells 17) is closed at the (+Y) side and / or (-Y) side end by a disk-shaped lid portion or the like that is substantially perpendicular to the Y direction. For this reason, the first fluid that has flowed into the heat exchange member 5c passes through the plurality of cells 17 in the outer region 101, but does not pass through the inner region 102.

[0100] As described above, the multiple cells 17 of the honeycomb structure 1c are arranged circumferentially along the inner peripheral surface of the outer peripheral wall 11, and the inner space of the multiple cells 17 (i.e., the inner region 102) is closed at the end in the axial direction (Y direction in the above example) of the honeycomb structure 1c. In the honeycomb structure 1c, the first fluid does not flow through a portion near the central axis J1 where the radial distance from the second fluid flowing around the heat exchange member 5c is relatively large, but flows through the multiple cells 17 in the outer region 101 where the distance is relatively small. Therefore, heat exchange between the first fluid and the second fluid via the heat exchange member 5c is suitably performed, and the efficiency of heat exchange can be improved.

[0101] Various modifications are possible to the above-described heat exchangers 7, 7a, 7b.

[0102] For example, in the heat exchanger 7 shown in FIG. 1, the second fluid supply section 63 may be connected to a portion on the (-Y) side (i.e., the upstream side) of the multiple heat exchange members 5, and the second fluid discharge section 64 may be connected to a portion on the (+Y) side (i.e., the downstream side) of the multiple heat exchange members 5.

[0103] 20 is a schematic diagram showing a cross section perpendicular to the Y direction of the second fluid supply unit 63, the second fluid discharge unit 64, and the second flow path forming units 61 of the heat exchanger 7. In the example shown in FIG. 20, the second fluid supply unit 63 includes a main supply pipe 631 extending substantially parallel to the X direction, and a plurality of supply branch pipes 632 extending substantially parallel to the Z direction from the main supply pipe 631 toward the (-Z) side and connected to the second flow path forming units 61, respectively. The second fluid discharge unit 64 includes a main discharge pipe 641 extending substantially parallel to the X direction, and a plurality of discharge branch pipes 642 extending substantially parallel to the Z direction from the main discharge pipe 641 toward the (+Z) side and connected to the second flow path forming units 61, respectively. The shapes of the second fluid supply unit 63 and the second fluid discharge unit 64 are not limited to the shapes exemplified in FIG. 20, and may be variously changed.

[0104] For example, in the example shown in FIG. 21, each supply branch pipe 632 extends obliquely from the supply main pipe 631 toward the (-Z) side and the (-X) side, and is connected to a portion on the (-Z) side of the end of the second flow path forming section 61 on the (+Z) side. The supply branch pipe 632 extends along a tangential direction at a connection portion with the supply branch pipe 632 of the second flow path forming section 61. Each discharge branch pipe 642 extends obliquely from the discharge main pipe 641 toward the (+Z) side and the (-X) side, and is connected to a portion on the (+Z) side of the end of the second flow path forming section 61 on the (-Z) side. The discharge branch pipe 642 extends along a tangential direction at a connection portion with the discharge branch pipe 642 of the second flow path forming section 61. This can reduce pressure loss in the second fluid supply section 63, the second flow path forming section 61, and the second fluid discharge section 64.

[0105] 22, the supply branch pipe 632 of the second fluid supply section 63 is omitted, and the supply main pipe 631 is directly connected to the end portion on the (+Z) side of the second flow path forming section 61. Also, the discharge branch pipe 642 of the second fluid discharge section 64 is omitted, and the discharge main pipe 641 is directly connected to the end portion on the (-Z) side of the second flow path forming section 61. This allows the heat exchanger 7 to be made more compact.

[0106] 23, the three supply branch pipes 632 are thicker from the side closer to the supply source of the second fluid to the side farther from it (i.e., from the (+X) side to the (-X) side). Also, the three discharge branch pipes 642 are thicker from the (+X) side to the (-X) side. This makes it possible to uniform the flow rates of the second fluid supplied to the three second flow path forming parts 61.

[0107] In the example shown in FIG. 24, the outer diameter and inner diameter of the three second flow path forming parts 61 increase from the side closer to the supply source of the second fluid to the side farther from it (i.e., from the (+X) side to the (-X) side). Therefore, the outer diameter of the heat exchange member 5 (not shown), which is approximately equal to the inner diameter of the second flow path forming parts 61, also increases from the (+X) side to the (-X) side. In this way, by miniaturizing the heat exchange member 5 inside the second flow path forming parts 61 on the (+X) side, which is closer to the supply source of the second fluid and where the flow rate of the second fluid is likely to be relatively large, excessive heat recovery from the first fluid can be suppressed.

[0108] 7, the (-Y) side buffer forming portion 66a may be omitted, and the second fluid discharge portion 64a may be connected to the (-Y) side ends of the four second intermediate flow paths 71a. Alternatively, in the heat exchanger 7a, the second fluid supply portion 63a may be connected to the (-Y) side buffer forming portion 66a, and the second fluid discharge portion 64a may be connected to the (+Y) side buffer forming portion 66a.

[0109] In the heat exchanger 7b shown in FIG. 15, the front flow passage 75b may be disposed on the (-Y) side of the partition wall 67b, and the rear flow passage 76b may be disposed on the (+Y) side of the partition wall 67b.

[0110] In the heat exchanger 7, the second flow passage 70 does not necessarily need to be provided over the entire length of the honeycomb structure 1 in the Y direction, and may be provided adjacent to the heat exchange member 5 only in a part of the honeycomb structure 1 in the Y direction. The same applies to the heat exchangers 7a and 7b.

[0111] In the heat exchanger 7, the enlarged flow passage portion 73 shown in FIG. 6 does not necessarily have to be provided, and for example, the radial width of each second flow passage 70 may be approximately the same at any position in the Y direction.

[0112] The structures of the first fluid supply section 53a and the first fluid discharge section 54a shown in Fig. 11 are not limited to the above example and may be modified in various ways. For example, the shape of the first fluid buffer section 56a is not limited to a substantially quadrangular pyramid shape and may be modified in various ways, such as a substantially dome shape. In addition, the connection position of the first fluid supply pipe 57a to the first fluid buffer section 56a may also be modified in various ways.

[0113] The honeycomb structures 1 and 1c may contain ceramics as a main component as described above, or may not contain ceramics as a main component.

[0114] The outer peripheral wall 11 of the honeycomb structure 1 does not necessarily have to be substantially cylindrical as long as it is cylindrical, and may be modified in various ways. For example, the cross-sectional shape of the outer peripheral wall 11 of the honeycomb structure 1 perpendicular to the Y direction may be a polygon such as a rectangle or a hexagon, or may be an ellipse. The same applies to the honeycomb structure 1c.

[0115] The temperature of the first fluid exchanged in the heat exchangers 7, 7a, 7b may be lower than the temperature of the second fluid.

[0116] In the heat exchanger 7 shown in FIG. 1, the number, size, arrangement, etc. of the multiple heat exchange members 5 arranged in parallel are not limited to the above example and may be changed in various ways. Also, in the heat exchanger 7, the sizes, structures, etc. of the multiple heat exchange members 5 may be different from each other. Furthermore, in the heat exchanger 7, other heat exchange members may be provided in addition to the multiple heat exchange members 5 arranged in parallel. The other heat exchange members may be arranged in parallel with the multiple heat exchange members 5, or may not be arranged in parallel. The same applies to the heat exchangers 7a and 7b.

[0117] For example, in the heat exchanger 7d shown in FIG. 25, four heat exchange members 5 are arranged in a staggered manner. Specifically, in each of the (-Z) side and (+Z) side portions of the outer wall portion 6d, two heat exchange members 5 are arranged side by side in the X direction, and the two heat exchange members 5 on the (+Z) side are positioned in a position shifted in the (-X) direction from the two heat exchange members 5 on the (-Z) side. In the heat exchanger 7e shown in FIG. 26, six heat exchange members 5 are arranged so as to surround the (+X) side, (-X) side, and (-Z) side of one large heat exchange member 5e. In the heat exchanger 7f shown in FIG. 27, eight heat exchange members 5 are arranged so as to surround the entire periphery of one large heat exchange member 5f.

[0118] The configurations in the above-described embodiment and each of the modified examples may be combined as appropriate as long as they are not mutually inconsistent. [Industrial Applicability]

[0119] The present invention can be used, for example, for heat recovery from exhaust gases of automobiles. [Explanation of symbols]

[0120] 1,1c Honeycomb structure 4 Covering part 5, 5c, 5e, 5f Heat exchanger 6,6a,6b Exterior wall 7,7a,7b,7d~7f Heat exchanger 11 Peripheral wall 17 Cells 18 Bulkhead 53a 1st fluid supply section 56a First fluid buffer section 57a 1st fluid supply pipe 67b Partition wall 70, 70a, 70b Second flow path 72a Second fluid buffer section 75b Front flow passage 76b Rear flow passage 77b Communication port 100 Interior Space 721a Protrusion J1 center axis

Claims

1. 1. A heat exchanger comprising: Each of the heat exchange members is a structure in which an outer peripheral surface of a honeycomb structure having a cylindrical outer peripheral wall and partition walls that divide an internal space of the outer peripheral wall, extend in an axial direction, and form a plurality of cells through which a first fluid flows, is covered with a cylindrical covering portion, and the outer peripheral surface of the honeycomb structure is covered with a cylindrical covering portion, and the heat exchange members are arranged in parallel at the same position in the axial direction. an outer wall portion that covers the outer peripheral surfaces of the heat exchange members while being spaced outward from the outer peripheral surfaces of the heat exchange members, thereby forming a flow path between the outer peripheral surfaces of the heat exchange members and the outer peripheral surfaces of the heat exchange members, through which a second fluid that exchanges heat with the first fluid flows; A heat exchanger comprising:

2. 2. The heat exchanger of claim 1, The flow passages are provided over the entire length of each honeycomb structure of the heat exchanger.

3. 3. The heat exchanger according to claim 1 or 2, A heat exchanger, wherein the cross-sectional area of ​​the flow passage at the upstream end of each honeycomb structure is larger than the cross-sectional area of ​​the flow passage at other portions of each honeycomb structure.

4. 3. The heat exchanger according to claim 1 or 2, the flow path includes a second fluid buffer portion that integrally surrounds an upstream end or a downstream end of the plurality of heat exchange members and temporarily stores the second fluid; The second fluid is divided and supplied from the second fluid buffer portion to the periphery of each of the plurality of heat exchange members.

5. 3. The heat exchanger according to claim 1 or 2, The flow path is a front flow passage that integrally surrounds the plurality of heat exchange members from one end portion in the axial direction to a center portion in the axial direction; a rear flow passage that is adjacent to the front flow passage in the axial direction via a partition wall, that integrally surrounds the heat exchange members from the other end of the heat exchange members in the axial direction to a center of the heat exchange members in the axial direction, and into which the second fluid flows from the front flow passage through a communication port provided between the rear flow passage and the front flow passage; Equipped with the communication port is provided at one end in a predetermined direction perpendicular to the axial direction at a position in the axial direction where the partition wall is provided, The second fluid is supplied to the front flow passage from an end portion of the front flow passage on the other side in the predetermined direction, The second fluid is discharged from the other end of the rear flow passage in the predetermined direction to the outside of the rear flow passage.

6. 3. The heat exchanger according to claim 1 or 2, a first fluid supply unit arranged upstream of the heat exchange members and supplying the first fluid to the heat exchange members; the first fluid supply unit includes a first fluid buffer unit that temporarily stores the first fluid and supplies the first fluid to the plurality of heat exchange members in a divided manner; the flow path includes an auxiliary flow path adjacent to the first fluid buffer portion, a heat exchanger in which heat exchange is performed between the first fluid in the first fluid buffer portion and the second fluid flowing through the auxiliary flow path;

7. 7. The heat exchanger according to claim 6, the first fluid supply section further includes a first fluid supply pipe that supplies the first fluid to the first fluid buffer section, The auxiliary flow passage is a heat exchanger that faces a supply port of the first fluid supply pipe in the axial direction with the first fluid buffer portion therebetween.

8. 7. The heat exchanger according to claim 6, The auxiliary flow passage is a heat exchanger that surrounds the inner space of the first fluid buffer section.

9. 3. The heat exchanger according to claim 1 or 2, A heat exchanger in which the multiple cells of the honeycomb structure are arranged circumferentially along the inner surface of the outer wall, and the inner spaces of the multiple cells are blocked at the axial ends of the honeycomb structure.

10. 3. The heat exchanger according to claim 1 or 2, The honeycomb structures of the heat exchange members are heat exchangers whose main component is ceramics.

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