JPH0825814B2 - Heat exchanger manufacturing method - Google Patents

Description

Detailed Description of the Invention [Industrial purpose]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat exchanger manufacturing method used for manufacturing a heat exchanger used for heat exchange between one fluid and another fluid. is there. (Prior Art) Conventionally, as a heat exchanger used for exchanging heat between one fluid and the other fluid, a tube type, a plate type, a heat exchanger having an enlarged heat transfer surface, There are those with various structures such as heat storage type, and as their materials, steel that is easily available and has good workability, and copper and copper that have good thermal conductivity and good workability Following alloys and copper, aluminum and aluminum alloys, which have good thermal conductivity, light weight and good workability, are used. For special applications, titanium, monel, nickel, glass, resin, etc. are used. Was used. Details of this type of heat exchanger can be found in "Handbook of Mechanical Engineering", May 15, 1988, 2nd edition, 2nd edition, Japan Society of Mechanical Engineers, pages B8-1 to B8-24. . (Problems to be Solved by the Invention) However, in such a conventional heat exchanger, the heat resistance and the corrosion resistance are insufficient, the strength is insufficient, or the weight is large. , Especially in the engine part of aerospace equipment, the temperature is 1700 ℃
There is a problem that it is not suitable for the heat exchanger used in the environment reaching the above. (Object of the Invention) The present invention has been made in view of such conventional problems, and is excellent in heat resistance and corrosion resistance, sufficiently strong in strength and thermal conductivity, and lightweight. In particular, it is an object of the present invention to provide a heat exchanger that can be used even in a high temperature environment such as an engine part of aerospace equipment.

Configuration of the Invention

(Means for Solving the Problems) A method of manufacturing a heat exchanger according to the present invention forms a fluid passage when manufacturing a heat exchanger having a fluid passage formed of a cylindrical partition wall and a spiral partition wall. A state in which a prepreg obtained by impregnating carbon fiber (including cloth-like one) with a resin is laminated on the side of the core that is arranged in a spiral shape and on which the cylindrical partition and the spiral partition are formed. And by the deformation of the core when the core is pressed, the laminated prepreg forming the cylindrical partition wall is pressed between the core and the molding jig and the spiral partition wall is formed. A tube made of carbon / carbon fiber composite material (C / C material) by heating the laminated prepreg while pressing it between the cores to heat the resin, and then carbonizing and graphitizing the resin. Forming partition walls and spiral partition walls, and The insulator is characterized in that the core is melted or burned during the carbonization / graphitization process to form a fluid passage, and the structure of the manufacturing method of such a heat exchanger solves the conventional problems described above. The carbon fiber used in the present invention is not particularly limited, but for example, PAN-based carbon fiber is used, and so-called fibrous ones as well as cloth-like (woven cloth, non-woven cloth-like cloth) The resin for forming the prepreg by impregnating the carbon fiber is not particularly limited, but for example, a phenol resin having a large carbon residual ratio after the carbonization / graphitization treatment is used. Further, the core in which such a prepreg is laminated on all or part of the surface is not particularly limited, but, for example, a sheet wax is suitable. It is possible to use those laminated in thickness or those molded with foamed rubber, etc. When this sheet core is made of sheet wax, it is melted and removed at the time of pressurization and heat treatment to remove foamed rubber. When it is used as a raw material, it is burned and removed during carbonization and graphitization, and when the former sheet wax is used, it acts to give a force in the direction orthogonal to the pressing direction to the laminated prepreg. It is smaller than when rubber is used,
Melt removal by heating is extremely good. And
When it is desired to apply a larger pressing force in the direction orthogonal to the pressing direction, the latter foamed rubber is used to utilize the elastic deformation of these foamed rubbers, for example, from one direction to all laminated prepregs. It is also desirable, if necessary, to apply a large pressing force. Further, if necessary, it is also desirable to subject the surface of the partition wall made of the carbon / carbon fiber composite material to an oxidation resistance treatment in which a layer of oxide or refractory metal is provided. (Operation of the Invention) Since the method for manufacturing a heat exchanger according to the present invention has the above-mentioned structure, it is lightweight and has high strength, and is also carbon / carbon fiber excellent in heat resistance, corrosion resistance and thermal conductivity. A heat exchanger in which a fluid passage is formed by a partition wall made of a composite material will be manufactured, and it has excellent heat resistance and corrosion resistance, as well as strength and thermal conductivity, and is lightweight. In particular, it has an effect of being sufficiently durable even in use in a high temperature environment such as an engine part of aerospace equipment. (Example) Example 1 Fig. 1 shows a heat exchanger manufactured in Example 1 of the present invention. The heat exchanger 1 is a partition wall 2 made of carbon / carbon fiber composite material (C / C material). (The outer cylindrical partition 2a, the inner cylindrical partition 2b, the spiral partition 2c), and the spiral fluid passage 3 formed by the partition 2 (2a, 2b, 2c), The cylindrical partition wall 2b also has a structure in which the straight fluid passage 4 is formed. The heat exchanger 1 having such a structure includes a larger heat exchanger 1 (1a) and a medium-sized heat exchanger 1 as shown in FIG.
(1b) and a smaller heat exchanger 1 (1c) are formed and used concentrically in combination, and liquid hydrogen is stored in the spiral fluid passage 3 from the liquid hydrogen storage container 6 through the liquid hydrogen supply pipe 7. Of the combustion gas (about 1700 ° C.) flowing in the direction of arrow A in the fluid passage 4 formed by the inner cylindrical partition wall 2b and the outer cylindrical partition wall 2a, the liquid hydrogen flows through the fluid passage 3 inside. During passing, it is gasified, and this hydrogen gas passes through the hydrogen gas supply pipe 8 in the direction of arrow B and is sent into the combustion chamber 9, where it reacts with oxygen in the atmosphere entering in the direction of arrow C and burns. The generated combustion gas flows in the direction of arrow D by the rotation of the turbine blade TB and enters the fluid passage 4 of the heat exchanger 1, and the inside of the fluid passage 4 of the heat exchanger 1 is indicated by arrow A.
It operates as a jet engine that continuously performs the operation of flowing in the direction and applying heat to the liquid hydrogen as described above to use this as hydrogen gas. Next, the order of manufacturing the heat exchanger 1 having such a structure will be described with reference to FIGS. 3 (a) to 3 (f) and FIG. FIG. 3 (a) shows a molding jig.
Reference numeral 10 denotes a tubular molding jig 11, an upper ring-shaped molding jig 12 fixed at the upper end of the tubular molding jig 11, and an axially slidable direction at the lower end of the tubular molding jig 11. The lower ring-shaped molding jig 13 provided on the. Next, as shown in FIG. 3 (b-2), a carbon fiber cloth (fourth core) is attached to the outside of the core 15 made of foamed silicone rubber.
A prepreg 16 (step 10 in FIG. 4) obtained by impregnating step 101) in the figure with a phenol resin (step 102 in FIG. 4) as a resin.
3) is cut to an appropriate size (step 104 in FIG. 4) and wound to prepare a prepreg laminated rod-like body 17 in which the prepreg 16 is laminated (step 105 in FIG. 4). Then, as shown in FIG. 3 (b-1) (however, with the lower ring-shaped molding jig 13 removed), a phenol resin is attached to the carbon fiber cloth on the inner peripheral side of the cylindrical molding jig 11. Laminating impregnated prepreg 18 (step 105 in FIG. 4)
After that, the prepreg laminated rod-like bodies 17 shown in FIG. 3 (b-2) are arranged in a spiral shape, and then, as shown in FIG. 3 (b-1).
As shown in FIG. 5, the lower ring-shaped molding jig 13 is mounted and compressed in the direction of the arrow E in the figure to stack the prepregs 16 and 18 (step 105 in FIG. 4). This compression causes the core 15 made of foamed silicone rubber to bulge toward the center (see FIG. 3 (C)), and in this state, as shown in FIG. 3 (C), the prepregs arranged in a spiral shape. On the inner peripheral side of the laminated rod body 17, a prepreg 19 in which a carbon fiber cloth is impregnated with a phenol resin is provided.
Are stacked (step 105 in FIG. 4). Next, as shown in FIG. 3 (d), the prepreg 19 is covered with a bleeder cloth 20, and a flexible molding jig 21 made of a polyamide resin film is further covered. Backing (step 106 in FIG. 4) is performed on the prepregs 16, 18, and 19 by providing and sealing the sealing compounds 22 and 23 at the ends. Subsequently, as shown in FIG. 3 (e), pressure / heat treatment (curing treatment (step 107 in FIG. 4)) is performed. This pressurization / heat treatment is performed while drawing a vacuum inside the flexible molding jig 21 made of a polyamide resin film,
The pressure applied at this time is several tens of kgf / cm ² (for example, 20 to 70 k
gf / cm ² ) at 150-160 ℃ for several hours (for example, 2
It is carried out by heating. During this pressurization / heat treatment, pressure is applied from the center side toward the molding jig 11 side in the direction of the arrow in FIG. 3 (e), so as shown in FIG. When the core 15 that is protruding toward the core is pushed and elastically deformed, the laminated prepregs 16, 18, and 19 are pressed between the core 15 and the molding jigs 11 and 21. At the same time, due to the elastic deformation of the core 15, the laminated prepreg 16 between the core 15 and another core 15 adjacent thereto and the molding jigs 12 and 13 is also in a pressed state. Since the phenol resin is cured by being heated, a carbon fiber-containing resin molded product having a good partition wall shape can be obtained. The phenol resin exuded during the pressure / heat treatment is included in the bleeder cloth 20. After this pressurizing / heating treatment is completed, the mold is released (step 108 in FIG. 4) to the state shown in FIG. 3 (f), and carbonization (step 109 in FIG. 4) / graphitization (step 109 in FIG. Step 110) shown in the drawing is performed to form the partition walls 2 (2a, 2b, 2c) made of carbon / carbon fiber composite material and to obtain the fluid passage 3 which is burned and removed by the core 15. To do. In this carbonization / graphitization treatment, pitch impregnation (4th
Step 111) in the figure, carbonization (step 112 in FIG. 4) and graphitization (step 113 in FIG. 4) are repeated several times to increase the density to the target density, and the final step is graphitization. (Step 113 in FIG. 4) ends. In this case, the carbonization (steps 109 and 112 in FIG. 4) is, for example, 600 to 800.
The resin (pitch) is carbonized by firing at about ° C. At this time, the temperature is raised, held and cooled in an inert gas atmosphere such as N ₂ gas for about 3 to 4 days. In the graphitization (steps 110 and 113 in FIG. 4), the matrix layer is graphitized by firing at about 2300 to 2600 ° C. At this time, for example
The temperature is raised, held and cooled in an inert gas atmosphere such as N ₂ gas for 6 to 7 days. Furthermore, pitch impregnation (4th
Step 111) in the figure is the temperature at which the pitch becomes liquid (about 300 ° C)
Pitch impregnation is performed by applying a pressure of about several Kgf / cm ^{2 at} . By thus completing the carbonization / graphitization treatment, as shown in FIG. 3 (f), the partition walls 2 (outer tubular partition wall 2a, inner tubular partition wall 2a made of a carbon / carbon fiber composite material are formed.
A heat exchanger 1 having a spiral fluid passage 3 formed by b and spiral partition walls 2c) and the core 15 being burned and removed during the carbonization / graphitization treatment is obtained. In the first embodiment, the core 15 made of foamed silicone rubber is used to manufacture the integrated heat exchanger 1. However, the core 15 made of sheet wax is used. Can also produce an integrated heat exchanger 1. And press the sheet wax
Elution during heat treatment (cure treatment) (for example, melting temperature 15
At 0 ° C.), the spiral fluid passage 3 is formed, and the carbonization / graphitization treatment is performed in this state. In this case, the core 15 made of sheet wax does not undergo elastic deformation as large as that of foamed silicon rubber, but foamed silicon rubber may cause some combustion residue when burned out during carbonization / graphitization treatment. On the other hand, with sheet wax, it is almost eluted during pressure and heat treatment. Example 2 FIG. 5 shows a heat exchanger manufactured in Example 2 of the present invention, and the heat exchanger 31 shown in FIG. 5 (c) is carbon / carbon as shown in FIG. 5 (a). An outer heat exchanger structure 35 having partition walls 32 (outer tubular partition wall 32a, spiral partition wall 32c) made of carbon fiber composite material, and as shown in FIG. 5 (b), carbon / carbon fiber composite material. As shown in FIG. 5 (c), the inner heat exchanger constructing body 36 having the partition wall 32 (inner cylindrical partition wall 32b, spiral partition wall 32d) made of a material is screwed into each other and combined. In addition, the partition wall 32 (32
a, 32b, 32c, 32d) has a spiral fluid passage 33, and the inner cylindrical partition wall 32b also has a straight fluid passage 34. Even in the heat exchanger 31 having such a structure, the second
As heat exchangers of, for example, three kinds of sizes as illustrated in the figure, these are concentrically combined and used. Next, the procedure for manufacturing the heat exchanger 31 having such a structure will be described with reference to FIG. 6. FIG. 6 (a-1) shows a molding jig for the outer heat exchanger structure 35. The molding jig 40 includes a tubular molding jig 41,
From the upper ring-shaped molding jig 42 fixed at the upper end of the tubular molding jig 41 and the lower ring-shaped molding jig 43 provided slidably in the axial direction at the lower end of the cylindrical molding jig 41. Has become. During manufacture, carbon fiber cloth (see step 10 in FIG. 4) is provided on the three sides of the core 45 made of foamed silicone rubber.
By cutting the prepreg 46 (step 103 in FIG. 4) impregnated with phenol resin (step 102 in FIG. 4) as a resin into 1) into an appropriate size (step 104 in FIG. 4) and winding the prepreg 46, Laminating the prepreg 46 (step 105 in FIG. 4)
The prepared prepreg laminated rod-shaped body 47 is prepared. Then, as shown in FIG. 6 (a-1) (however, with the lower ring-shaped molding jig 43 removed), a phenol resin is attached to the carbon fiber cloth on the inner peripheral side of the cylindrical molding jig 41. Laminating impregnated prepreg 48 (step 105 in FIG. 4)
After that, the prepreg laminated rod-shaped body 47 is attached to the prepreg 46.
Laminating the prepregs 46 and 48 by arranging them in a spiral shape with the non-laminated surface inside, and mounting the lower ring-shaped molding jig 43 and compressing it in the upward direction of FIG. 6 (a-1). (Step 105 in FIG. 4) is performed. Then, as shown in FIGS. 6 (a-1) and (a-2),
The inner peripheral side of the prepreg laminated rod-shaped body 47 arranged in a spiral shape is covered with a bleeder cloth 50, and further covered with a flexible molding jig 51 made of a polyamide resin film, and the end of the molding jig 51 made of a polyamide resin film. Backing for the prepregs 46 and 48 by providing sealing compounds 52 and 53 on the parts and sealing (step 106 in FIG. 4)
I do. Subsequently, pressurization / heat treatment (cure treatment) is performed. At this time, during pressurization / heat treatment, the inside surrounded by the molding jig 51 made of a polyamide resin film is evacuated,
Due to the elastic deformation of the core 45 when pressed, the laminated prepregs 46 and 48 are pressed between the core 45 and the molding jigs 41 and 51, and at the same time, the core 45 and the core 45 adjacent thereto. And forming jig
The laminated prepreg 46 is pressed between 42 and 43, and the phenol resin exuded from the prepregs 46 and 48 by this pressurization is included in the bleeder cloth 50. After the pressurization / heating treatment is completed, carbonization / graphitization treatment is performed to form the partition walls 32 (32a, 32c) made of the carbon / carbon fiber composite material, and the core 45 is burned and removed. An outer heat exchanger structure 35 having a spiral recess is obtained. FIG. 6 (b-1) shows a forming jig for the inner heat exchanger structure 36. The forming jig 60 includes a tubular forming jig 61,
From the upper ring-shaped molding jig 62 fixed at the upper end of the tubular molding jig 61 and the lower ring-shaped molding jig 63 provided slidably in the axial direction at the lower end of the cylindrical molding jig 61. Has become. During manufacture, carbon fiber cloth (see step 10 in FIG. 4) is provided on the three sides of the core 65 made of foamed silicone rubber.
The prepreg 66 impregnated with phenol resin (step 102 in FIG. 4) as a resin is wound around 1) to prepare a prepreg laminated rod-shaped body 67 in which the prepreg 66 is laminated. Then, with the lower ring-shaped molding jig 63 removed, a prepreg 68 in which carbon fiber cloth is impregnated with a phenol resin is laminated on the outer peripheral side of the cylindrical molding jig 61, and then the prepreg laminated rod-shaped body 67. Are arranged in a spiral shape with the surface not laminated with the prepreg 66 on the outside, and the lower ring-shaped molding jig 63 is mounted and compressed upward in FIG. 6 (b-1) to obtain the prepreg 66, Laminate 68. Then, as shown in FIGS. 6 (b-1) and (b-2),
The prepreg laminated rod-shaped body 67 arranged in a spiral shape is covered with a bleeder cloth 70 on the outer peripheral side, and further covered with a flexible molding jig 71 made of a polyamide resin film, and the sealing compound 72 is applied to the end of the polyamide resin film 71. 7
By providing 3 and sealing, backing (step 106 in FIG. 4) is performed on the prepregs 66 and 68. Subsequently, pressurization / hot-pressing treatment (cure treatment) is performed, and at this time, the polyamide resin film (71) is being pressed / heated.
The inside of the box 65 and the forming jigs 61, 71 are made by the elastic deformation of the core 65 when it is pressurized.
The laminated prepreg 66, 68 is pressed between the core 65 and the core 65 and the molding jigs 62, 63 adjacent to the core 65, and the laminated prepreg 66 is pressed by this pressure. The phenol resin exuded from 66, 68 should be included in the bleeder cloth 70. After the pressurization / heating treatment is completed, carbonization / graphitization treatment is performed to form the partition walls 32 (32b, 32d) made of the carbon / carbon fiber composite material, and the core 65 is burned and removed. An inner heat exchanger arrangement 36 having a spiral recess is obtained. Then, the outer heat exchanger component 35 and the inner heat exchanger component 36 thus obtained are engaged with each other in the screw direction to form a carbon / carbon fiber composite as shown in FIG. 5 (c). Partition wall 32 (outer cylindrical partition wall 32a, inner cylindrical partition wall 32
b and spiral partition walls 32c, 32d) and a heat exchanger having a spiral fluid passage 33 formed by burning and removing the cores 45, 65 during the carbonization / graphitization treatment. Get 31 In addition, in the second embodiment, a case where the heat exchanger 31 of the split constitution type is manufactured by using the one made of foamed silicone rubber as the cores 45, 65 has been described. The heat exchanger 31 of the split constitution type can be manufactured by using the following. Then, the sheet wax is eluted at the time of heating / pressurizing treatment (curing treatment) to form a spiral recess, and carbonization / graphitization treatment is performed in this state. In this case, the core 45,65 made of sheet wax,
Although not as elastically deformed as foamed silicone rubber, as described above, the elution is excellent during the pressurization / heat treatment.

【The invention's effect】

In the method for manufacturing a heat exchanger according to the present invention, in manufacturing a heat exchanger having a fluid passage formed by a cylindrical partition wall and a spiral partition wall, the heat exchanger is arranged in a spiral shape to form the fluid passage. On the surface side forming the cylindrical partition wall and the spiral partition wall of the child, a state in which a prepreg impregnated with carbon fiber resin is laminated, and the core is deformed when the core is pressed, Heating the laminated prepreg forming the partition wall between the core and the molding jig, and pressing the laminated prepreg forming the spiral partition between the core and the core. The resin is cured, and then carbonized / graphitized to form a cylindrical partition wall and a spiral partition wall made of a carbon / carbon fiber composite material, and the core is melted or burned down during the heating or carbonizing / graphitizing treatment. Let the fluid passage Since it is configured to be formed, a heat exchanger in which a fluid passage is formed by a partition wall made of a carbon / carbon fiber composite material that is lightweight, has high strength, and is excellent in heat resistance, corrosion resistance, and thermal conductivity Since it is manufactured, and therefore it has excellent heat resistance and corrosion resistance, as well as sufficient strength and thermal conductivity, and is lightweight, it is especially used in the engine part of aerospace equipment. A remarkable advantage is that a heat exchanger that can sufficiently withstand use even in a high temperature environment can be manufactured.

[Brief description of drawings]

FIG. 1 is an explanatory view of a slope of a heat exchanger manufactured according to Embodiment 1 of the present invention, FIG. 2 is an explanatory view showing a case where the heat exchanger of FIG. 1 is applied to a jet engine, and FIG. ) ~
(F) and FIG. 4 are cross-sectional explanatory views and process flow charts sequentially showing the process for manufacturing the heat exchanger of FIG. 1, and FIG. 5 (a).
(B) and (c) are slope explanatory views of the heat exchanger constructing body and the heat exchanger manufactured according to the second embodiment of the present invention, and FIG. 6 (a).
-1) and (a-2) are sectional explanatory views showing the manufacturing procedure of the outer heat exchanger structure shown in FIG. 5 (a), and FIG. 6 (b-).
1) (b-2) is a cross-sectional explanatory view showing a manufacturing procedure of the inner heat exchanger structure shown in FIG. 5 (b). 1 ... Heat exchanger, 2 (2a, 2b, 2c) ... Partition wall made of carbon / carbon fiber composite material, 3 ... Fluid passage, 15 ... Core, 16 ... Prepreg, 31 ... Heat exchanger , 32 (32a, 32b, 32c, 32d ... partition wall made of carbon / carbon fiber composite material, 33 ... fluid passage, 45, 65 ... core, 46, 66 ... prepreg.

Claims (1)

[Claims] 1. When manufacturing a heat exchanger having a fluid passage formed of a tubular partition and a spiral partition, the tubular partition of a core arranged in a spiral shape to form the fluid passage, and On the surface side forming the spiral partition, a prepreg in which carbon fiber is impregnated with a resin is laminated, and the cylindrical partition is formed by the deformation of the core when the core is pressed. While pressing the prepreg between the core and the molding jig and heating the laminated prepreg that forms the spiral partition between the core and the core, the resin is cured by heating while heating. Carbonization / graphitization treatment is performed to form a tubular partition wall and a spiral partition wall made of a carbon / carbon fiber composite material, and the core is melted or burned down during the heating or carbonization / graphitization treatment to form a fluid passage. Characterized by Method of manufacturing a heat exchanger.