JP2020026907A - Manufacturing method for heat exchanger - Google Patents

Abstract

To improve heat exchanging efficiency.SOLUTION: A first molding step includes a honeycomb molding step of molding a plurality of honeycomb compacts each having a cylindrical peripheral wall 21 and cell walls 22 for partitioning the internal of the peripheral wall 21 into a plurality of cells C1, and an arranging step of arranging the plurality of honeycomb compacts along the axial directions of the peripheral walls 21 in such a manner as to shift the positions of the cell walls 22.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a method for manufacturing a heat exchanger.

Patent Literature 1 describes a method for manufacturing a heat exchanger.
As shown in FIG. 11, a plurality of ribs 53 are formed on a surface of a ceramic sheet material 51 by using a cylindrical roller 52. A laminated body is manufactured by laminating a plurality of sheet members 51 each having the rib 53 formed thereon, and after firing the laminated body, it is housed in a case to manufacture a heat exchanger.

JP-A-2002-5593

  In the heat exchanger of Patent Document 1, the plurality of ribs 53 are provided continuously from one end of the sheet material 51 to the other end thereof. Since the fluid flows between the plurality of ribs 53 along the ribs 53, the flow of the fluid tends to be in a rectified state. When the flow of the fluid is in a rectified state, it is difficult to perform heat transport. Therefore, there is a problem that the heat exchange efficiency is low. The present invention has been made in view of such circumstances, and an object of the present invention is to provide a method of manufacturing a heat exchanger that can improve heat exchange efficiency.

  A method of manufacturing a heat exchanger according to the present invention for solving the above-mentioned problems includes a plurality of first flow passages, a plurality of second flow passages, and a partition wall that partitions the first flow passage and the second flow passage. Wherein a heat exchange is performed between the first fluid flowing through the first flow passage and the second fluid flowing through the second flow passage via the partition wall. The first molding step of molding the first molded body having the first flow path, the second molding step of molding the second molded body having the second flow path, A laminating step of laminating the molded body and the second molded body to obtain a laminated body, a degreasing step of degreasing the laminated body to obtain a porous body, and an impregnating step of impregnating the porous body with metallic silicon. The first forming step includes a cylindrical peripheral wall and a cell wall that partitions the inside of the peripheral wall into a plurality of cells. The present invention has a honeycomb forming step of forming a plurality of cam formed bodies, and an arrangement step of arranging the plurality of honeycomb formed bodies along the axial direction of the peripheral wall so as to shift the position of the cell wall. .

  According to the above configuration, by providing an arrangement step of disposing the plurality of honeycomb formed bodies along the axial direction of the peripheral wall so as to shift the position of the cell wall, irregularities can be formed in the first flow passage, For example, it is possible to branch one flow passage. This makes it difficult to form a boundary layer that inhibits the transfer of heat formed between the first fluid flowing through the first flow passage and the cell wall that forms the first flow passage. Can be promoted. Therefore, the heat exchange efficiency can be improved.

  In the method for manufacturing a heat exchanger according to the present invention, in the disposing step, the position of the cell wall is shifted by disposing a plurality of honeycomb formed bodies having the same shape in a state of being rotated in a circumferential direction of the peripheral wall. Is preferred. According to the above configuration, it is easy to dispose the cell walls along the axial direction in a state where the cell walls are shifted from each other, so that the disposing step can be performed efficiently.

  In the method for manufacturing a heat exchanger according to the present invention, in the honeycomb formed body, the cells may have two or more rows in both directions of a lamination direction of the first molded body and the second molded body and a direction intersecting the lamination direction. Preferably, it is provided. According to the above configuration, since the number of cell walls in the first flow passage can be increased, heat transport of the first fluid flowing through the first flow passage can be promoted. Thereby, heat exchange efficiency can be improved.

  In the method for manufacturing a heat exchanger of the present invention, it is preferable that, in the arranging step, the positions of the cell walls between the adjacent honeycomb formed bodies are shifted to be equal to or greater than the thickness of the cell walls. According to the above configuration, since the first flow passage can be branched, heat transport of the first fluid flowing through the first flow passage is easily promoted.

  In the method for manufacturing a heat exchanger of the present invention, it is preferable that, in the arranging step, five or more honeycomb formed bodies are arranged. According to the above configuration, since the first flow passage can be formed with many irregularities or branches, heat transport of the first fluid flowing through the first flow passage is more easily promoted.

  The method for manufacturing a heat exchanger of the present invention preferably further includes a firing step of firing the porous body. According to the above configuration, since the porous body is fired, the porous body can be hardly damaged in the impregnation step.

  According to the present invention, heat exchange efficiency can be improved.

The perspective view of a heat exchanger. FIG. 2 is a sectional view taken along line 2-2 of FIG. 1. FIG. 3 is a sectional view taken along line 3-3 in FIG. 1. Explanatory drawing of a 1st shaping | molding process (honeycomb shaping | molding process). Explanatory drawing of a 1st shaping | molding process (arrangement process). Explanatory drawing of a 2nd shaping | molding process. Explanatory drawing of a lamination process. Explanatory drawing which shows the state which arrange | positioned the laminated body in the container. 4 is a graph showing a temperature change in the container. The front view of the 1st molded object of a modification. Explanatory drawing of the shaping process in the heat exchanger of a prior art.

Hereinafter, an embodiment of the heat exchanger will be described.
As shown in FIG. 1, the heat exchanger 10 of the present embodiment includes a first circulation part (gas circulation part 20) including a first circulation passage (gas circulation passage R <b> 1) and a second circulation passage (heat medium circulation passage). R2) and a second circulation section (heat medium circulation section 30). The heat medium circulating portions 30 are arranged at both ends in the juxtaposition direction, and the gas circulating portions 20 and the heat medium circulating portions 30 are alternately arranged inside each heat medium circulating portion 30. The heat exchange is performed between the gas flowing through the gas flow passage R1 and the liquid heat medium flowing through the heat medium flow passage R2.

Next, the heat medium circulating unit 30 will be described.
As shown in FIGS. 1 and 2, the heat medium circulating unit 30 includes two rectangular plate members 31 having the same shape and a plurality of walls connecting the two plate members 31 at predetermined intervals. A portion 32 is provided, and is formed in a honeycomb shape as a whole. That is, since the plurality of wall portions 32 are provided between the two plate members 31, a large number of cells C2 constituting the heat medium flow passage R2 are formed between the plate members 31. The cell C2 forms a cell row arranged in one row. The two plate members 31 and the plurality of wall portions 32 connecting the two plate members 31 function as partition walls that partition the heat medium flow passage R2.

  Here, as shown in FIG. 1, the direction in which the gas circulation unit 20 and the heat medium circulation unit 30 are juxtaposed is referred to as “width direction DX”, and the direction in which the cells C2 are arranged is referred to as “front-back direction DY”. The direction in which the cell C2 extends is referred to as “vertical direction DZ”.

  As shown in FIG. 2, both ends of the cell C2 in the vertical direction DZ are open. An opening at the upper end of the cell C2 forms an inlet 15a for the heat medium, and an opening at the lower end of the cell C2 forms an outlet 15b for the heat medium, and a heat medium passage between the inlet 15a and the outlet 15b. R2 is formed. The cell C2 may have, for example, a cell structure in which the wall thickness of the plate member 31 and the wall portion 32 is 0.1 to 0.5 mm and the cell pitch is 1 to 10 mm. As the heat medium flowing through the heat medium flow passage R2, for example, a known liquid heat medium can be used. Known heat media include, for example, cooling water (Long Life Coolant: LLC) and organic solvents such as ethylene glycol.

Next, the gas circulation unit 20 will be described.
As shown in FIGS. 1 and 3, the gas distribution unit 20 includes a cylindrical peripheral wall 21 and a cell wall 22 that divides the inside of the peripheral wall 21 into a plurality of cells C1, and is configured in a honeycomb shape as a whole. That is, a number of cells C1 forming the gas flow passage R1 are formed inside the peripheral wall 21. The cells C1 are arranged in three rows in the width direction DX and constitute seven cell rows in the vertical direction DZ. The cylindrical peripheral wall 21 and the cell wall 22 function as partition walls that partition the gas flow passage R1.

  As shown in FIG. 3, both ends of the cell C1 in the front-back direction DY are open. The gas inlet 16a is formed by the opening at one end of the cell C1 in the front-rear direction DY, and the gas outlet 16b is formed by the opening at the other end of the cell C1 in the front-rear direction, and the inlet 16a and the outlet 16b are formed. A gas flow passage R1 is formed between them. The cell C1 may have, for example, a cell structure in which the wall thickness of the peripheral wall 21 and the cell wall 22 is 0.1 to 0.5 mm and the cell pitch is 1 to 10 mm.

  As shown in FIG. 3, the cell C1 is configured such that the position of the cell wall 22 is shifted in the vertical direction DZ at each point where the length of the gas flow passage R1 is divided into approximately five equal parts in the front-back direction DY. . Specifically, the position of the cell wall 22 adjacent in the front-rear direction DY is shifted in the vertical direction DZ by more than the thickness of the cell wall 22, and the middle position of each cell wall 22 in the vertical direction DZ , A cell wall 22 adjacent in the front-rear direction DY is located. Since the position of the cell wall 22 is shifted as described above, the gas flow path R1 is branched into a plurality of branches.

Examples of the gas flowing through the gas flow passage R1 include an exhaust gas of an internal combustion engine and an intake gas to the internal combustion engine.
The material forming the heat medium flowing part 30 and the gas flowing part 20 is a material made of silicon carbide containing silicon carbide as a main component. A material containing silicon carbide as a main component has high thermal conductivity and can increase heat exchange efficiency. Here, “main component” means 50% by mass or more.

Next, the flow path configuration of the heat exchanger 10 will be described.
As shown in FIG. 1, the heat exchanger 10 is configured in a state where the gas circulation unit 20 and the heat medium circulation unit 30 are connected. The cell C2 of the heat medium circulating section 30 and the cell C1 of the gas circulating section 20 are configured to extend in directions orthogonal to each other. Specifically, the cell C2 of the heat medium circulating unit 30 is configured to extend in the vertical direction DZ, and the cell C1 of the gas circulating unit 20 is configured to extend in the front-rear direction DY. Then, heat exchange is performed between the gas flowing through the cell C1 of the gas flow part 20 and the heat medium flowing through the cell C2 of the heat medium flow part 30 via the partition wall.

A method for manufacturing the heat exchanger 10 will be described with reference to FIGS.
The heat exchanger 10 is manufactured through a first forming step, a second forming step, a laminating step, a degreasing step, and an impregnating step described below.

(First molding step)
In the first forming step, the position of the cell wall 22 is shifted, and the honeycomb forming step of forming a plurality of honeycomb formed bodies 17 each having a cylindrical peripheral wall 21 and a cell wall 22 that partitions the inside of the peripheral wall 21 into a plurality of cells C1. In this way, there is an arrangement step of arranging the plurality of honeycomb formed bodies 17 along the axial direction of the peripheral wall 21 to form a first formed body (first honeycomb formed body 18).

[Honeycomb forming process]
As a raw material composition used for forming the honeycomb formed body 17, a clay-like mixture containing silicon carbide particles, an organic binder, and a dispersion medium is prepared.

  Examples of the organic binder include polyvinyl alcohol, methyl cellulose, ethyl cellulose, and carboxymethyl cellulose. Among these organic binders, methyl cellulose and carboxymethyl cellulose are particularly preferred. Further, only one kind of the above organic binders may be used, or two or more kinds may be used in combination.

  Examples of the dispersion medium include water and an organic solvent. Examples of the organic solvent include ethanol. Further, only one of the above dispersion media may be used, or two or more of them may be used in combination.

  Further, other components may be further contained in the mixture. Other components include, for example, ceramic particles, a plasticizer, and a lubricant made of a material other than silicon carbide. Examples of the ceramic particles made of a material other than silicon carbide include ceramic particles made of a carbide such as tantalum carbide and tungsten carbide, and nitrides such as aluminum nitride, silicon nitride, and boron nitride. Examples of the plasticizer include polyoxyalkylene compounds such as polyoxyethylene alkyl ether and polyoxypropylene alkyl ether. Examples of the lubricant include glycerin.

  As shown in FIG. 4, a honeycomb formed body 17 is formed using the clay-like mixture. The honeycomb formed body 17 can be formed, for example, by extrusion. The honeycomb formed body 17 includes a first cell C1a having a substantially square cross section and a half of the first cell C1a having a dimension in the vertical direction DZ which is substantially half of the first cell C1a. And two cells C1b. The second cell C1b is provided so as to be located at one end of the gas circulation unit 20 in the vertical direction DZ.

[Placement process]
As shown in FIG. 4, a plurality of honeycomb formed bodies 17 having the same shape are prepared, and each honeycomb formed body 17 is arranged along the axial direction of the peripheral wall 21 while being rotated 180 degrees in the circumferential direction of the peripheral wall 21.

  As shown in FIG. 5, the first formed body (the first formed body 18) is formed by arranging five honeycomb formed bodies 17 having the same shape while being rotated by 180 degrees in the circumferential direction of the peripheral wall 21. . As shown in FIG. 3, in the first honeycomb formed body 18, the position of the cell wall 22 adjacent in the front-rear direction DY is shifted in the vertical direction DZ by more than the thickness of the cell wall 22. Specifically, the cell wall 22 adjacent in the front-rear direction DY is located at an intermediate position between the cell walls 22 in the vertical direction DZ.

  Each honeycomb formed body 17 may be disposed via an adhesive layer. As the adhesive, a mixture of an inorganic binder and inorganic particles can be used. Examples of the inorganic binder include silica sol and alumina sol, and examples of the inorganic particles include silicon carbide and silicon nitride.

(Second molding step)
As a raw material composition used for forming the second formed body, a clay-like mixture composed of the same raw material composition as that of the first honeycomb formed body 18 is used.

  As shown in FIG. 6, a second formed body (second honeycomb formed body 19) is formed using the clay-like mixture. The second honeycomb formed body 19 can be formed, for example, by extrusion.

(Lamination process)
As shown in FIG. 7, the first honeycomb formed body 18 and the second honeycomb formed body 19 are stacked in a predetermined order to form a stacked body 24. The first honeycomb formed body 18 constitutes a gas circulation unit 20 through a degreasing step and an impregnation step described later. The second honeycomb formed body 19 constitutes the heat medium flowing unit 30 through a degreasing step and an impregnation step described later. The first honeycomb formed body 18 and the second honeycomb formed body 19 may be laminated via an adhesive layer. As the adhesive, the same adhesive as used in the disposing step can be used. A drying process is performed on the stacked body 24 as necessary. Specific examples of the drying treatment include a drying treatment using a microwave dryer, a hot air dryer, a dielectric dryer, a reduced pressure dryer, a vacuum dryer, a freeze dryer, or the like.

(Degreasing process)
The degreasing step is a step of heating and burning off the organic components contained in the laminate. Through the degreasing step, a porous body having a skeleton portion arranged in a state where the silicon carbide particles are in contact with each other is obtained.

(Impregnation step)
The impregnation step is a step of impregnating the interior of the porous partition wall with metallic silicon. Through the impregnation step, metallic silicon is filled between the silicon carbide particles constituting the partition wall.

Here, in the manufacturing method of the present embodiment, the degreasing step and the impregnating step are continuously performed by multi-stage heat treatment in different temperature ranges.
As shown in FIG. 8, the laminate 24 is placed in a heat-resistant container 40 having a bottomed box shape made of graphite or the like. FIG. 8 illustrates the laminated body 24 with its cross-sectional shape omitted. The stacked body 24 is placed on the support 41 disposed on the bottom surface of the container 40, and thus is disposed in the container 40 via the support 41. The support 41 is formed in a size and a shape that comes into contact with only a part of the lower surface of the laminate 24, and supports the laminate 24 at one or several points on the lower surface of the laminate 24. The number of supports 41 may be one or more.

  Examples of the shape of the support 41 include a prism, a column, a truncated pyramid, and a truncated cone. Among these, a truncated pyramid shape and a truncated cone shape are particularly preferable because the number of contact points with the lower surface of the laminate 24 can be reduced.

  The support 41 is made of a porous material having continuous pores of a size that causes a capillary phenomenon. Examples of the porous material forming the support 41 include a porous material made of silicon carbide and a porous material made of carbon such as graphite. The porosity of the porous material constituting the support 41 is, for example, 20 to 60%.

  Further, in the gap S between the bottom surface of the container 40 and the laminated body 24 placed on the support 41, a solid metal silicon 42 such as powder, granule, or lump is disposed. As the metal silicon 42, it is preferable to use metal silicon having a purity of less than 98%. Solid metallic silicon tends to have a lower melting point as its purity decreases. Therefore, by using low-purity metallic silicon, the heating temperature required for the impregnation step can be kept low. As a result, manufacturing costs can be reduced. The purity of the metallic silicon is, for example, 95% or more.

  The amount of the metal silicon 42 contained in the container 40 is, for example, an amount corresponding to the sum of the pore volume of the porous body obtained from the laminate 24 and the pore volume of the support 41 (for example, 1.00 to 1.00 of the above sum). 1.05 times the volume). In this case, the porosity of the heat exchanger 10 can approach 0%. In addition, the usage amount of the metal silicon 42 is suppressed, and the manufacturing cost can be suppressed.

  As described above, with the laminate and the metal silicon 42 arranged in the container 40, the container 40 is placed under an inert atmosphere such as argon or nitrogen or under vacuum using a known heating means such as a firing furnace. Heat. At this time, the container 40 is subjected to multi-stage heating in different temperature ranges.

  Specifically, as shown in FIG. 9, the primary heating is performed by raising the temperature in the container 40 to the first temperature and holding the temperature at the first temperature for a certain time. Thereafter, the temperature inside the container 40 is increased to a second temperature higher than the first temperature, and is maintained for a certain period of time to perform secondary heating. Then, the temperature in the container 40 is decreased.

  Primary heating is a heat treatment corresponding to a degreasing step. The first temperature of the primary heating is a temperature at which the organic components are burned off and lower than the melting point of metallic silicon, and is set according to the type of the organic components contained in the laminate 24. By the primary heating, the organic components contained in the laminate 24 are burned off, and the laminate 24 becomes porous. At this time, since the temperature (first temperature) in the container 40 is lower than the melting point of the metal silicon, the metal silicon 42 contained in the container 40 is maintained in a solid state.

  The first temperature is, for example, preferably from 400 ° C. to 1400 ° C., and more preferably from 450 ° C. to 1000 ° C. By setting the temperature in the above range, the organic components can be more reliably burned off while suppressing the melting of the metal silicon 42.

  The primary heating is preferably performed until the organic components contained in the laminate 24 are completely removed. For example, by a preliminary test, a heating time for forming a porous body from which organic components contained in the laminate 24 have been removed is measured in advance, and the temperature in the container 40 is set to the first temperature with the elapse of the heating time. To the second temperature.

  Secondary heating is a heat treatment corresponding to the impregnation step. The second temperature of the secondary heating is set to be equal to or higher than the melting point of metallic silicon. By the secondary heating, the metal silicon 42 contained in the container 40 is melted. Then, the molten metal silicon enters the gaps of the silicon carbide particles constituting the partition wall of the porous body through the support 41 made of a porous material by the capillary phenomenon, and the gaps are impregnated with the metal silicon 42. At this time, the metal silicon 42 is also impregnated at the boundary between the heat medium flowing part and the gas flowing part in the porous body, so that the boundary between the honeycomb formed bodies and the boundary between the heat medium flowing part and the gas flowing part disappears. I do.

Thereby, the metal exchanger 42 is impregnated in the gaps between the silicon carbide particles constituting the partition wall, and the heat exchanger 10 in which the plurality of heat medium circulating portions and the gas circulating portions are integrated is obtained.
The second temperature is preferably, for example, a temperature of 1420 ° C. or higher. By setting the temperature in the above range, it is possible to more reliably impregnate the silicon metal.

  The second temperature is, for example, preferably 2000 ° C. or lower, and more preferably 1900 ° C. or lower. By setting the temperature in the above range, the production cost can be reduced in terms of facilities and energy. Further, the thermal expansion of the porous body is suppressed, and damage due to the thermal expansion hardly occurs.

  Further, the second temperature is preferably a temperature lower than the sintering temperature of silicon carbide contained in the mixture used in the forming step (for example, 2000 ° C. or lower). By setting the temperature in the above-mentioned temperature range, the obtained heat exchanger 10 is in a non-sintered state in which almost all of the silicon carbide particles as its constituent components are not sintered but exist independently. This unsintered state has a high Young's modulus and is hardly deformed, and is useful as a heat exchanger.

  The secondary heating is preferably performed until the gap between the silicon carbide particles constituting each wall of the porous body is sufficiently impregnated with metallic silicon. For example, when the amount of the metal silicon 42 contained in the container 40 is an amount corresponding to the sum of the pore volume of the porous body and the pore volume of the support 41, all the metal silicon 42 is impregnated. Thus, it can be determined that the metal silicon has been sufficiently impregnated.

  After the secondary heating, the temperature in the container 40 is lowered, the heat exchanger 10 is taken out from the container 40, and the support 41 integrated with the lower surface of the heat exchanger 10 is separated. Thereby, the heat exchanger 10 is obtained.

  Through the above-described impregnation step, a plurality of gas flow paths R1, a plurality of heat medium flow paths R2, and partition walls that partition the gas flow paths R1 and the heat medium flow paths R2 are provided. The heat exchanger 10 in which heat exchange is performed between the flowing gas and the liquid heat medium flowing through the heat medium flow passage R2 via the partition wall can be obtained.

Next, the operation and effect of the present embodiment will be described.
(1) A honeycomb forming step of forming a plurality of honeycomb formed bodies each having a cylindrical peripheral wall and a cell wall that partitions the inside of the peripheral wall into a plurality of cells, and a plurality of honeycomb formed bodies by shifting the positions of the cell walls. Is disposed along the axial direction of the peripheral wall. Since the plurality of honeycomb formed bodies are arranged so as to shift the position of the cell wall, it is possible to form irregularities in the gas flow passage or to branch the gas flow passage. This makes it difficult to form a boundary layer that hinders the transfer of heat formed between the gas and the cell walls that form the gas flow passages. Heat transport can be facilitated. Therefore, the heat exchange efficiency can be improved.

  (2) In the arranging step, the positions of the cell walls are shifted by arranging a plurality of honeycomb formed bodies having the same shape rotated by 180 degrees in the circumferential direction of the peripheral wall. Therefore, it is easy to dispose the cell walls along the axial direction while displacing the positions of the cell walls, so that the disposing step can be performed efficiently.

  (3) In the honeycomb formed body, the cells are provided in two or more rows in both the laminating direction of the first honeycomb formed body and the second honeycomb formed body and the direction intersecting the laminating direction. Since the number of cell walls in the gas flow passage can be increased, heat transport of the gas flowing through the gas flow passage can be promoted. Therefore, the heat exchange efficiency can be improved.

  (4) In the disposing step, the positions of the cell walls of the adjacent honeycomb formed bodies are displaced so as to be equal to or more than the thickness of the cell walls. Therefore, since the gas flow passage can be branched, heat transport of the gas flowing through the gas flow passage is further facilitated.

  (5) In the arranging step, five or more honeycomb formed bodies are arranged. Since many branches of the gas flow passage can be formed, heat transport of the gas flowing through the gas flow passage is further facilitated.

This embodiment can be implemented with the following modifications. Further, the configuration of the above-described embodiment and the configuration shown in the following modified examples can be appropriately combined and implemented.
-The first fluid flowing through the first flow passage is not limited to gas. The second fluid flowing through the second flow passage is not limited to the heat medium. The first fluid may be a heat carrier and the second fluid may be a gas. Both the first fluid and the second fluid may be gas or both may be heat medium.

  -The fluid flowing through the first flow passage and the second flow passage is not limited to only the first fluid and the second fluid. For example, the second fluid and a third fluid different from the second fluid may flow through the second flow passage.

-The lamination form of a gas distribution part and a heat medium distribution part is not limited to the aspect of this embodiment. The order of lamination of the gas circulation part and the heat medium circulation part, and the number of layers to be laminated can be appropriately selected.
In the present embodiment, the heat medium inlet is formed at one end in the vertical direction DZ of the heat medium flowing portion, and the heat medium outlet is formed at the other end in the vertical direction DZ. However, the present invention is not limited to this mode. . An outlet for the heat medium may be formed at one end of the vertical direction DZ, and an inlet for the heat medium may be formed at the other end of the vertical direction DZ. Similarly, the position of the inflow port and the outflow port of the gas flow section may be reversed.

  -The cells of the first honeycomb formed body are not limited to the form in which two or more rows are provided in both directions of the lamination direction of the first honeycomb formed body and the second honeycomb formed body and the direction intersecting the stacking direction. A mode in which only one row is provided in a direction intersecting the lamination direction of the first honeycomb formed body and the second honeycomb formed body may be employed.

  The arrangement step is not limited to a mode in which a plurality of honeycomb formed bodies having the same shape are prepared, and each honeycomb formed body is arranged along the axial direction of the peripheral wall while being rotated 180 degrees in the circumferential direction of the peripheral wall. By preparing a plurality of honeycomb formed bodies having different cell wall positions and arranging the honeycomb formed bodies along the axial direction of the peripheral wall, the position of the cell wall between adjacent honeycomb formed bodies may be shifted. Alternatively, the position of the cell wall may be shifted by preparing a plurality of honeycomb formed bodies having the same shape and arranging the honeycomb formed bodies along the axial direction of the peripheral wall while being entirely shifted.

  -The arrangement step is not limited to the mode in which the position of the cell wall between adjacent honeycomb formed bodies is shifted to be equal to or more than the thickness of the cell wall. It may be displaced by less than the thickness of the cell wall. Even in a mode in which the cells are staggered by less than the thickness of the cell wall, unevenness can be formed on the surface of the cell constituting the gas flow passage, so that heat transport of the gas flowing through the cell can be promoted. .

  -The arrangement step is not limited to the mode in which the honeycomb formed bodies are arranged such that the position of the cell wall adjacent to the front-back direction DY is shifted in the up-down direction DZ. Each honeycomb formed body may be arranged such that the position of the cell wall adjacent to the front-back direction DY is shifted in the width direction DX. Further, for example, as shown in FIG. 10, each honeycomb formed body 17 may be arranged such that the position of the cell wall 22 adjacent to the front-back direction DY is shifted in both the vertical direction DZ and the width direction DX.

  A baking step may be inserted between the degreasing step and the impregnation step. By firing the degreased porous body, it is possible to improve the strength of the porous body and prevent the porous body from being damaged in the impregnation step. In the firing step, the temperature can be 2100 ° C. to 2250 ° C., and the holding time can be 1 to 5 hours.

  The technical ideas that can be grasped from the above-described embodiment and its modifications will be described below together with their effects. In the honeycomb forming step, a honeycomb formed body including a plurality of first cells and a plurality of second cells whose vertical dimension is substantially half the size of the first cells is formed. It is provided so as to be located at one end in the vertical direction of the circulation part.

  Since the honeycomb formed body has the above configuration, a simple operation of rotating a plurality of honeycomb formed bodies of the same shape in the circumferential direction of the peripheral wall by 180 degrees along the axial direction with the positions of the cell walls shifted from each other. Can be arranged.

R1: first flow path (gas flow path), R2: second flow path (heat medium flow path), C1 ... cell, C2 ... cell, 10 ... heat exchanger, 17 ... honeycomb formed body, 18 ... first formed Body (first honeycomb formed body), 19 ... second formed body (second honeycomb formed body), 24 ... laminated body.

Claims (6)

A plurality of first flow paths, a plurality of second flow paths, and a partition wall that partitions the first flow path and the second flow path; a first fluid flowing through the first flow path; A method for producing a silicon carbide heat exchanger in which heat exchange is performed between the second fluid flowing through a second flow passage and the second fluid through the partition wall,
A first molding step of molding a first molded body having the first flow passage;
A second molding step of molding a second molded body having the second flow passage;
A laminating step of laminating the first molded body and the second molded body to obtain a laminated body;
A degreasing step of degreasing the laminate to obtain a porous body,
Impregnation step of impregnating the porous body with metal silicon,
The first forming step is a honeycomb forming step of forming a plurality of honeycomb formed bodies having a cylindrical peripheral wall and a cell wall that partitions the inside of the peripheral wall into a plurality of cells, and displacing the positions of the cell walls. Arranging a plurality of the honeycomb formed bodies along the axial direction of the peripheral wall.   The method for manufacturing a heat exchanger according to claim 1, wherein, in the arranging step, a plurality of honeycomb formed bodies having the same shape are arranged in a state of being rotated in a circumferential direction of the peripheral wall to shift a position of a cell wall. .   3. The honeycomb formed body according to claim 1, wherein the cells are provided in two or more rows in both directions of a stacking direction of the first formed body and the second formed body and a direction intersecting the stacking direction. 4. Production method of heat exchanger.   The method for manufacturing a heat exchanger according to any one of claims 1 to 3, wherein, in the arranging step, the positions of the cell walls of the adjacent honeycomb formed bodies are shifted to be equal to or more than the thickness of the cell walls. .   The method for manufacturing a heat exchanger according to any one of claims 1 to 4, wherein in the arranging step, five or more honeycomb formed bodies are arranged. The method for manufacturing a heat exchanger according to any one of claims 1 to 5, further comprising a firing step of firing the porous body.