US20120267087A1

US20120267087A1 - Fiber-reinforced body, method for producing the body and pipe or tube sheet having the body

Info

Publication number: US20120267087A1
Application number: US13/525,856
Authority: US
Inventors: Marcus Franz
Original assignee: SGL Carbon SE
Current assignee: SGL Carbon SE
Priority date: 2009-12-17
Filing date: 2012-06-18
Publication date: 2012-10-25
Also published as: BR112012014847A2; CA2783126C; CA2783126A1; KR20120112552A; DE102009054910A1; RU2012130063A; JP2013514512A; KR101426631B1; CN102713493A; EP2513589A1; WO2011082866A1

Abstract

A body includes a ceramic material and is suitable for use in a heat exchanger and for conducting fluids. An outer side of the body is at least partially encompassed by at least two fiber bundles in the longitudinal and/or circumferential direction and force-lockingly connected thereto. The fiber bundles are pre-tensioned and neighboring sections of the fiber bundles are disposed at a predetermined distance. A method for producing a body includes providing a body including a ceramic material and being suitable for use in a heat exchanger and for conducting fluids, and encompassing at least sections of the outer side of the body with at least two fiber bundles under a predetermined pretension forming a force-locking connection and with neighboring sections of the fiber bundle disposed at a predetermined distance. A heat exchanger pipe or tube sheet includes the body.

Description

CROSS-REFERENCE TO RELATED APPLICATION

This is a continuation, under 35 U.S.C. §120, of copending International Application No. PCT/EP2010/067211, filed Nov. 10, 2010, which designated the United States; this application also claims the priority, under 35 U.S.C. §119, of German Patent Application DE 10 2009 054 910.2, filed Dec. 17, 2009; the prior applications are herewith incorporated by reference in their entirety.

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates to a fiber-reinforced body, a method for the production thereof and a pipe or a pipe bottom or tube sheet having the body in a heat exchanger.
Components made from ceramic material, such as silicon carbide pipes, are often used in heat exchangers. Since they are formed of ceramic materials, leak-proof silicon carbide pipes are prone to brittle fracture. In the event of mechanical failure, the pipes fracture catastrophically, i.e. into fractured sections. The pipe loses its integrity. A heat exchanger that has been made from pipes of that kind may be destroyed by a fracture of that nature, as corrosive acids reach the heat exchanger's service compartment, which is not protected against corrosion. In addition, further damage may occur in the cooling system or the heating system to which the heat exchanger is connected.

SUMMARY OF THE INVENTION

It is accordingly an object of the invention to provide a fiber-reinforced body, a method for producing the body and a pipe or tube sheet having the body, which overcome the hereinafore-mentioned disadvantages of the heretofore-known devices and methods of this general type and which provide a material that is immune to catastrophic brittle fracture.
With the foregoing and other objects in view there is provided, in accordance with the invention, a body, comprising a ceramic material which is suitable for use in a heat exchanger and for conducting fluids. The outer side of the body is at least partially encompassed by at least two fiber bundles in the longitudinal direction and/or the circumferential direction and force-lockingly connected thereto. The fiber bundles are pre-tensioned. Neighboring sections of the fiber bundles are disposed at a predetermined distance. Reinforcing the body through the use of the fiber bundles means that it becomes more immune to brittle fracture and its pressure resistance and load-bearing capacity are increased. A force-locking connection is one which connects two elements together by force external to the elements, as opposed to a form-locking connection which is provided by the shapes of the elements themselves.
The fiber reinforcement improves the properties of bodies as follows: It provides an increase in bursting pressure, the body becomes more immune to brittle fracture, steam hammering and unpermitted exceeding of the operating pressure. Even if fluids are conducted through the fiber-reinforced body during routine operation and a longitudinal crack appears therein, as a result of its age, for example, improper use or overstress, this body does not exhibit any significant leaks up to a predetermined differential pressure. The pushing out or breaking out of fragments of the body is intercepted to a certain extent due to the encompassing of the body with fiber bundles, in such a way that a piece pushing or breaking out of the original form of the body is retained in a predetermined form by the surrounding pre-tensioned fiber bundle. The breaking out of pieces from the body and therefore the emergence of large quantities of fluid are prevented. The heat exchanger in which the body is used can usually be further operated without interruption until there is a planned shutdown. The body according to the invention is therefore leak-proof to a certain extent, even in a defective state, in comparison with an unreinforced body.
In accordance with another feature of the invention, the body is preferably a pipe-shaped body. Within the meaning of the present invention, a pipe-shaped body is particularly taken to mean a body which preferably has a circular cross-section and is open at the ends of its longitudinal extension, in order to be suitable for conducting fluids. Alternatively, however, the pipe-shaped body may also exhibit a square, oval or other shaped cross-section. The longitudinal extension of the pipe-shaped body is preferably greater than its cross-section. The pipe-shaped body is preferably a pipe with a circular cross-section.
Alternatively, in accordance with a further feature of the invention, the body is a cover, wherein a plurality of holes extends in the longitudinal direction of the cover. A cover, in the context of the present invention, is taken to mean a body with a preferably circular cross-section, which does not exhibit a single cavity, but a plurality of cavities. In order for it to be suitable for conducting fluids, the cover has a plurality of holes, which extend in the longitudinal direction of the cover and therefore represent cavities. Within the meaning of the present invention, the cover is regarded as a pipe-shaped body, the length dimension of which is not crossed or traversed by a single cavity, but by a plurality of cavities, which may lead into a single cavity within the longitudinal extension of the cover or may continuously extend separately along the longitudinal direction of the cover. The longitudinal extension of the cover is preferably smaller than its cross-section. It may be so small, for example, that the cover exhibits the shape of a round disc or plate, which is crossed or traversed by holes extending in the longitudinal direction. The entire cross section of the cover may exhibit a plurality of holes. Alternatively, it is also conceivable that only at least a partial section exhibits a plurality of holes.
In accordance with an added preferred feature of the invention, the fiber bundles form a network. This means, for example, that the at least two fiber bundles are inclined towards one another, at ±80° for example, to the longitudinal axis of the body.
The density of the network depends on the nature of the body's application, the load to which the body is exposed and the strength and dimensions of the body. If it is expected that the body will break into smaller fragments in case of a fracture, a dense network of fiber bundles is desirable. On the other hand, the greater use of materials in fiber bundles also raises costs, so that the density of networked fiber bundles being used should be individually adapted to the desired effects with regard to the resulting material costs.
In accordance with an additional preferred feature of the invention, the ratio of the distance between neighboring fiber bundles to the diameter of the fiber bundles is between 5:1 and 10:1. It is a function of the body's mechanical load. The body's thermal resistance in proportion to the ratio is substantially unchanged. In each direction at an angle to the longitudinal extension of the fiber bundles, comparatively thin fiber bundles and uncovered strips with a broad surface area alternate on the outer side of the body.
The at least two fiber bundles may encompass or reinforce the body partially or completely. A complete reinforcement is desirable where bodies are subject to heavy loads. Alternatively, it may also be expedient, out of cost considerations, for only those parts of the body that are subject to particularly heavy loads to be reinforced. In the case of pipes, for example, end sections, in particular, which are connected to other components, are areas in an apparatus such as a heat exchanger which are subject to a particular load or prone to fractures and may require particular protection in the form of reinforcement. If the body is a temperature-loaded component, it should furthermore be taken into consideration that the body and fiber bundle may have different thermal expansion coefficients and the length and width of the fiber bundle configuration should be adapted accordingly. The fiber bundles should therefore be disposed in such a manner on the at least one outer side of the body, that the body's thermal expansion can be compensated by the fiber bundles or can be allowed without leading to the destruction of the body.
In accordance with yet another feature of the invention, the ceramic material is preferably dense sintered silicon carbide. It is chosen for its outstanding properties such as, for example, high thermal conductivity, high strength, high corrosion resistance to acid and base media and high load-bearing capacity. The silicon carbide is preferably pressureless sintered silicon carbide, which exhibits extremely high corrosion resistance to acid and base media, which it can likewise withstand to very high temperatures, high temperature change resistance, high thermal conductivity, high wear resistance and a hardness resembling that of diamond. As a further alternative, the silicon carbide may be a liquid phase-sintered silicon carbide, which is produced from silicon carbide and different oxide ceramics and is distinguished by its great strength.
The silicon carbide may contain at least one ceramic or mineral filler material, wherein the choice of filler materials is adapted to the application. Examples of filler materials are materials from the group of naturally occurring flake graphite, artificially produced electrographite, soot or carbon, graphite or carbon fibers or borocarbide. Furthermore, ceramic or mineral filler materials may be used in grain, platelet or fiber form, as silicates, carbonates, sulfates, oxides, glass or selected mixtures thereof.
In accordance with yet a further preferred feature of the invention, the fiber bundles are carbon fiber bundles. A carbon fiber bundle has good tensile strength, corrosion resistance and stiffness, low breaking elongation and is resistant at the application temperatures of loaded bodies. The specific performance of the carbon fiber bundles means that the pre-tensioning of the reinforcement is retained, even if the pipe is subject to highly variable or dynamic loads. Due to the negative thermal longitudinal expansion coefficient of carbon fiber bundles, the reinforcement is further pre-tensioned in case of a temperature rise, the bursting and leak-tight pressure is greater at a higher temperature than at room temperature. The carbon fiber reinforcement improves the properties of bodies, particularly in the case of silicon carbide pipes, as follows: an increase in bursting pressure is provided, the body becomes more immune to steam hammering and unpermitted exceeding of the operating pressure, since the body's bursting pressure at room temperature is 30 to 40% greater depending on the dimensions, as compared with a non-reinforced body. Other examples of fiber bundles are glass fiber bundles or aramid fiber bundles.
In accordance with yet an added preferred feature of the invention, the force-locking connection between the fiber bundles and the outer side of the body is an adhesive system. It is used to fix the fiber bundles to the body. The adhesive system is chosen from the group including adhesives which are made up of phenolic resin, epoxy resin or polysilazane-based resin. If necessary, the adhesive system may contain a silicon or silicon carbide filler material. It is also referred to as cement in the present invention. The adhesive system may include one or more of the adhesives mentioned earlier and/or cement. If necessary, the adhesive or cement may further contain a hardening catalyst and/or a plasticizer. Adhesives or cements of this kind are usually oxidation-resistant. These adhesives or cements also adhere well to both a ceramic material, such as silicon carbide, and also to fiber bundles, such as carbon fiber bundles, and are capable of wetting a fiber effectively.
The adhesive system is preferably a phenol resin. More preferably, the phenol resin is a resol. Alternatively, the phenol resin may also be a novolac. Resin systems containing bisphenol A-diglycidyl ether or bisphenol F-diglycidyl ether are also suitable as epoxy resin. In particular, resin systems which contain methyl hexahydrophthalic acid anhydride, particularly in a quantity of 25 to 50% by weight, in addition to more than 50% by weight bisphenol A-diglycidyl ether or bisphenol F-diglycidyl ether, based on the total weight in each case, are suitable as epoxy resin systems. A polysilazane resin system may also preferably be used as the adhesive system.
All of the adhesives mentioned above may further contain silicon or silicon carbide as the filler material. The plasticity of the cement may be adjusted to the desired adhesive bond through the use of the proportion of resin in the mixture or by adding plasticizer. The use of cement containing silicon or silicon carbide alongside the resin adhesive is particularly suitable when it is applied to the fiber bundle. Through impregnation of the fiber bundle with the cement and subsequent burning, silicon with carbon fibers can form silicon carbide or with silicon carbide as the filler material the impregnated and burnt carbon fiber exhibits silicon carbide.
The choice of adhesive system depends on the desired bond and crucially on the nature of the application of the body according to the invention. When selecting an epoxy resin as the adhesive system, which is applied to the body or with which the fiber bundle is impregnated and hardened, a greater reduction in tension is not possible, due for example to the brittleness of the hardened layer, a rigid connection is retained between the fiber bundles and the body. By using plasticizers, this connection can be made deformable, in order to intercept possible shear stresses or different expansions of the fiber bundles and the body during temperature changes, for example.
The body and the fiber bundles may be fixed through the use of an adhesive system, wherein the adhesive system is either applied to the body, the fiber bundles or both and then hardened or burnt. Alternatively, the body and the fiber bundles may each be provided with an adhesive system independently of one another and fixed to one another. The adhesive systems applied in this case may be identical or different. The choice depends on the adhesive power required and may be appropriately chosen and adapted by the person skilled in the art.
The adhesive system may be disposed at points or in sections between the body and the fiber bundles, so that a number of predetermined points on the fiber bundle are fixed to the body. Alternatively, the fiber bundles may be completely fixed to the body through the use of adhesion. The fiber bundles are preferably completely fixed to the body.
The fiber bundles may exist in the form of a yarn. This is particularly true when the fiber bundles are wound onto bodies and possibly fixed there. A yarn is taken to be a fiber bundle made up of a plurality of filaments. The yarn may exhibit sections running straight, diagonally and/or in a curved fashion. In order to create a network, at least one, preferably two, yarns intersect at predetermined points at a desired angle, preferably ±80°. Yarn sections may also be intertwined, meshed or integrated in some other way.
Otherwise, the fiber bundles may also be in the form of braiding, laid webs, knitted fabric, woven fabrics or interlaced yarns, preferably woven fabrics or interlaced yarns, which are pulled onto the body in a pre-tensioned state and fixed where necessary. Braiding is taken to mean an area-measured fabric, which is produced through the intersection of braid/thread systems running diagonally in opposite directions, wherein the braided threads cross one another at an adjustable angle to the fabric edge. A laid web is regarded as an area-measured fabric made up of one or more stretched, superimposed thread systems with different orientation directions, with or without fixing of the points of intersection. A knitted fabric is an area-measured fabric, in which the meshes are formed individually and consecutively from a horizontally laid thread, in addition further thread systems can also be incorporated for reinforcement. An area-measured fabric containing at least two thread systems usually crossing one another at right angles is regarded as a woven fabric. An interlaced yarn is an area-measured fabric, which is produced from one or more threads through the simultaneous formation of meshes in a longitudinal direction. Further threads may, of course, be incorporated for additional reinforcement. At least one fiber bundle of a predetermined length is regarded as the thread in this case. A thread system is taken to mean several threads.
It is, of course, also possible, when the fiber bundles are disposed in the form of a woven fabric or interlaced yarn, for the woven fabric or interlaced yarn to be longer than the body, so that where necessary the woven fabric or interlaced yarn protects the connection of the body to a further component through its configuration on the body.
With the objects of the invention in view, there is also provided a method for producing a body. The method comprises:

- a) providing a body which includes a ceramic material and is suitable for use in a heat exchanger and for conducting fluids; and
- b) encompassing at least sections of the outer side of the body by at least two fiber bundles under a predetermined pre-tension forming a force-locking connection, wherein neighboring sections of the fiber bundle are disposed at a predetermined distance.

With this method, the body's pressure resistance usually required in equipment production is achieved by reinforcing the body with fiber bundles. The pre-tensioning used according to the invention may be adjusted by a person skilled in the art according to the fiber material and area of application of the body.
In accordance with another mode of the invention, step b) may preferably include encompassing at least sections of the outer side of the body by at least two fiber bundles, so that the fiber bundles are in the form of a network. Alternatively, it is conceivable for the fiber bundles to be pulled around the body in the form of an area-measured fabric. Step b) is preferably carried out in such a way that the ratio of the distance between neighboring fiber bundles and the diameter of the fiber bundles is between 5:1 and 10:1. The increase in the strength of the body is thereby achieved with a relatively small covering of the outer side or surface of the body.
In accordance with a further preferred mode of the invention, before step b) an adhesive system is at least partially applied to the fiber bundle and/or the body and then hardened or burned. The fiber bundle configuration is thereby fixed to the outer side of the body. The adhesive system used for fixing is preferably chosen from the group including adhesives, which are formed from phenol resin, epoxy resin or polysilazane-based resin and are possibly mixed with silicon and silicon carbide filler material. Adhesive systems of this kind are readily workable and can be adapted to the shape of the body or are well-suited to the impregnation of a fiber, they exhibit good adhesive strength to a ceramic material such as silicon carbide and many types of fibers and, in particular, to a carbon fiber, following thermal hardening or burning.
The body and the fiber bundles may be fixed through the use of an adhesive system, wherein the adhesive system is applied either to the body, the fiber bundle or to both and then hardened or burned. An adhesive system which does not contain silicon or silicon carbide as the filler material is hardened, while an adhesive system containing silicon or silicon carbide as the filler material is burnt. Hardening is preferably carried out at temperatures between 120 and 180° C. for one to up to two hours, in a pressureless environment or at pressures of between 0.5 and 1.5 bar. At high temperatures, i.e. around 170 to 180° C., a hardening time of up to 15 minutes is generally sufficient. The higher the temperature is, the shorter the hardening time. If the adhesive system contains a hardening catalyst, the hardening may also take place at room temperature. Burning is preferably carried out at temperatures of over 1500° C. for up to 2 hours, in a pressureless environment or at pressures of 0.5 to 1.5 bar. Following the hardening of the adhesive or burning of the cement, the fiber bundles are disposed on the outer side of the body.
The body and the fiber bundles may each be provided with an adhesive or cement independently of one another and then fixed. The adhesives or cements applied may be identical or different in this case. A person skilled in the art may select suitable adhesives or cements, which adhere well to one another.
In accordance with an added preferred mode of the method of the invention, the fiber bundles are impregnated with an adhesive or cement, after which they are hardened or burned and finally disposed on the body.
The adhesive system may be disposed between the body and fiber bundles at points or in sections, so that a number of predetermined points of the fiber bundles are fixed to the body. Alternatively, the fiber bundles may be completely fixed to the body through the use of adhesive or cement. The fiber bundles are preferably completely fixed to the body.
The body used in the method according to the invention is preferably a pipe-shaped body or cover, wherein a plurality of holes extends in the longitudinal direction of the cover.
The ceramic material used in the method according to the invention is preferably silicon carbide, which optionally contains at least one ceramic or mineral filler material.
In the method according to the invention, the fiber bundles are preferably carbon fiber bundles. The carbon fiber bundles may be wound around the body in a predetermined pre-tensioned state in the form of a yarn. Alternatively, the carbon fiber bundles may exist in the form of braiding, laid webs, knitted fabric, woven fabric or interlaced yarns, preferably woven fabric or interlaced yarns, and are drawn over the at least one outer side of the body possibly provided with a hardened adhesive or burnt cement. On the other hand, it is conceivable for the carbon fiber bundle to be used in the method according to the invention as fiber bundles provided with hardened adhesive or burnt cement. Particularly in the case of carbon fiber bundles, the use of cement with silicon as the filler material is suitable, since silicon can react with the carbon fiber during the burning process to produce silicon carbide and a firmer bond between the carbon fiber and the cement can thereby be achieved.
With the objects of the invention in view, there is concomitantly provided a pipe, pipe base or tube sheet in a heat exchanger, comprising the body according to the invention.
The body according to the invention is particularly suitable for use as a pipe, for example for heat exchangers where there is increased mechanical stress and/or extremely corrosive media and solvents, and also for all other components subject to pressure and temperature loads. It is a particularly ideal material for the construction of heat exchangers, because it is highly thermally conductive, pressure-resistant and immune to brittle fracture. The body according to the invention is particularly preferably used as the pipe in a heat exchanger, because it is erosion-resistant and permits high flow velocities and a self-cleaning effect of the pipe is therefore achievable through fast-flowing media, which may be charged with particles. In addition or alternatively, the body according to the invention is preferably used as a pipe base or tube sheet in a heat exchanger. In assembled form, several pipe-shaped bodies and covers according to the invention are used as a pipe bundle heat exchanger.
A heat exchanger including a body according to the invention exhibits the following structure in accordance with German Patent Application DE 197 14 423, for example. The heat exchanger includes a casing, a base with supports, a spacer to create a distributor space, a distributor base with the inner and outer pipe bases or tube sheets and pipes disposed in the bores of the pipe bases and sealed therein through the use of a sealant. The base and casing are customarily screw-fastened, wherein the spacer is inserted in between to create the distributor space. The inner pipe base of the distributor base is smaller in diameter than the inner casing diameter. The outer pipe base is greater in diameter and therefore assumes the sealing function between the casing and the distributor space. The pipes represent the body according to the invention in the form of a pipe made from pressureless sintered silicon carbide, the outer side of which is encompassed by pre-tensioned carbon fiber bundles. If there is a temperature increase, the pre-tensioning of the reinforcement is advantageously increased by the negative thermal expansion coefficient of the carbon fiber. The heat exchanger then works more reliably and safely. In addition or alternatively, the outer and/or inner pipe base may further include pressureless sintered silicon carbide, which is encompassed by pre-tensioned carbon fiber bundles. Alternatively, in addition to the silicon carbide pipe and the network of carbon fiber bundles, the pipes further exhibit one of the adhesive systems described above for fixing the two elements. If the adhesive system is oxidation-resistant, oxidation media may also be used for cooling or heating in the service space of the heat exchanger constructed through the use thereof.
Other features which are considered as characteristic for the invention are set forth in the appended claims.
Although the invention is illustrated and described herein as embodied in a fiber-reinforced body, a method for producing the body and a pipe or pipe base or tube sheet having the body, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.
The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

FIG. 1 is a diagrammatic, side-elevational view of a body according to the invention;

FIG. 2 is a partially longitudinal-sectional, side-elevational view of the body according to the invention shown in FIG. 1;

FIG. 3 is an enlarged, longitudinal-sectional view of a portion III-III enclosed by a dot-dash line in FIG. 2; and

FIG. 4 is a longitudinal-sectional view of a portion of a further body according to the invention.

DETAILED DESCRIPTION OF THE INVENTION

Referring now to the figures of the drawings in detail and first, particularly, to FIG. 1 thereof, there is seen a diagrammatic side view of a body assembly 1 according to the invention. The body assembly 1 includes a smooth-walled body or pipe 3 made from pressureless sintered silicon carbide. The pipe 3 has an opening at both of its two ends 5, 7, so that it is suitable for conducting fluids. The pipe 3 has yarns 9 made from carbon fiber bundles wound around it, with the bundles being highly pre-tensioned and acting as reinforcement for the pipe 3. The yarns 9 have a non-illustrated phenol resin layer, which acts as an adhesive layer. The yarns 9 are wound around the pipe 3 in such a manner that they cross at predetermined points, so that they form a network.
A further diagrammatic side view of the body 1 according to the invention shown in FIG. 1, is depicted in FIG. 2. In FIG. 2, the same reference numbers are used for the same elements as in FIG. 1. In FIG. 2, the smooth-walled pipe 3 is likewise shown with the pipe ends 5, 7 and with the pipe having yarns 9 made from pre-tensioned carbon fiber bundles with a phenol resin layer wound around it. A part of the pipe, which is shown in cross-section, further shows a pipe wall 13 of the pipe 3, which has an inner side 14 and an outer side 15. The inner side 14 delimits a hollow cavity 11 of the pipe 3, which is unrestricted in the longitudinal direction and ends in an opening at each of the pipe ends 5, 7. A fluid may be conducted through the cavity 11 which is limited by the inner side 14. The yarns 9 are disposed on the outer side 15 of the pipe wall 13.
FIG. 3 shows an enlarged portion of FIG. 2, which is enclosed in FIG. 2 by a dot-dash line and marked with reference symbols III-III. In FIG. 3, the same reference numbers are used for the same elements as in FIG. 2. It can be seen from the enlarged view that the yarns 9 are disposed on the outer side 15 of the pipe wall 13, while the cavity 11 is formed by the inner side 14 of the pipe wall 13.
FIG. 4 shows a cross section through a portion of a further body assembly 41 according to the invention. The body assembly 41 according to the invention has a body or smooth-walled pipe 43 made from pressureless sintered silicon carbide. The pipe 43 has a pipe wall 413, which has an inner side 414 and an outer side 415. An adhesive 417 made from phenol resin is disposed on the outer side 415 of the pipe wall 413, on which yarns 49 made from carbon fibers are disposed. The adhesive 417 is only located in those areas of the outer side 415 of the pipe 413 in which the yarns 49 are disposed. The adhesive 417 is used to fix the yarns 49 to the outside 415 of the pipe wall 413. The pipe has a cavity 411, which is limited by the inner side 414 of the pipe wall 413 of the pipe 43.

Claims

1. A body assembly, comprising:

a ceramic material body configured for use in a heat exchanger and for conducting fluids, said body having an outer side and longitudinal and circumferential directions;

at least two fiber bundles at least partially encompassing and force-lockingly connected to said outer side of said body in at least one of said longitudinal and circumferential directions; and

said fiber bundles being pre-tensioned and having neighboring sections disposed at a predetermined distance from each other.

2. The body assembly according to claim 1, wherein said body is a pipe-shaped body or cover having a plurality of holes extending in said longitudinal direction, and said fiber bundles form a network.

3. The body assembly according to claim 1, wherein said fiber bundles have a diameter, and a ratio of said predetermined distance between neighboring sections of said fiber bundles and said diameter of said fiber bundles is between 5:1 and 10:1.

4. The body assembly according to claim 1, wherein said fiber bundles are carbon fiber bundles.

5. The body assembly according to claim 1, wherein said ceramic material is dense sintered silicon carbide.

6. The body assembly according to claim 5, wherein said dense sintered silicon carbide contains at least one ceramic or mineral filler material.

7. The body assembly according to claim 1, wherein said force-locking connection between said fiber bundles and said outer side is an adhesive system selected from the group of adhesives consisting of phenolic resin, epoxy resin and polysilazane-based resin.

8. The body assembly according to claim 7, wherein said adhesive system is mixed with silicon and silicon carbide filler material.

9. A method for the production of a body assembly, the method comprising the following steps:

a) providing a body including a ceramic material and being configured for use in a heat exchanger and for conducting fluids; and

b) encompassing at least sections of an outer side of the body with at least two fiber bundles under a predetermined pre-tension forming a force-locking connection and with neighboring sections of the fiber bundle disposed at a predetermined distance from each other.

10. The method according to claim 9, which further comprises carrying out step b) by encompassing at least sections of the outer side of the body with at least two fiber bundles in the form of a network.

11. The method according to claim 9, which further comprises carrying out step b) by encompassing at least sections of the outer side of the body with at least two fiber bundles having a ratio of the predetermined distance between neighboring sections of the fiber bundles and a diameter of the fiber bundles of between 5:1 and 10:1.

12. The method according to claim 9, which further comprises, before step b), at least partially applying an adhesive system to the body and/or the fiber bundle and then hardening or burning the adhesive system.

13. The method according to claim 12, which further comprises selecting the adhesive system from the group of adhesives consisting of phenolic resin, epoxy resin and polysilazane-based resin.

14. The method according to claim 13, which further comprises mixing the adhesives with silicon and silicon carbide filler material.

15. The method according to claim 9, wherein the body is a pipe-shaped body or cover having a plurality of holes extending in longitudinal direction of the cover.

16. The method according to claim 9, wherein the fiber bundles are carbon fiber bundles.

17. The method according to claim 9, wherein the ceramic material is dense sintered silicon carbide.

18. The method according to claim 17, wherein the dense sintered silicon carbide contains at least one ceramic or mineral filler material.

19. A heat exchanger pipe or tube sheet, comprising:

a body assembly according to claim 1.