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EP0996848A1 - Heat exchanger - Google Patents

Heat exchanger

Info

Publication number
EP0996848A1
EP0996848A1 EP98921490A EP98921490A EP0996848A1 EP 0996848 A1 EP0996848 A1 EP 0996848A1 EP 98921490 A EP98921490 A EP 98921490A EP 98921490 A EP98921490 A EP 98921490A EP 0996848 A1 EP0996848 A1 EP 0996848A1
Authority
EP
European Patent Office
Prior art keywords
heat exchanger
exchanger according
tube
elements
sub
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
EP98921490A
Other languages
German (de)
French (fr)
Other versions
EP0996848B1 (en
Inventor
Walter Krenkel
Martin Nedele
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Deutsches Zentrum fuer Luft und Raumfahrt eV
Original Assignee
Deutsches Zentrum fuer Luft und Raumfahrt eV
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Deutsches Zentrum fuer Luft und Raumfahrt eV filed Critical Deutsches Zentrum fuer Luft und Raumfahrt eV
Publication of EP0996848A1 publication Critical patent/EP0996848A1/en
Application granted granted Critical
Publication of EP0996848B1 publication Critical patent/EP0996848B1/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Classifications

    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F28HEAT EXCHANGE IN GENERAL
    • F28FDETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
    • F28F1/00Tubular elements; Assemblies of tubular elements
    • F28F1/10Tubular elements and assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with projections, with recesses
    • F28F1/12Tubular elements and assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with projections, with recesses the means being only outside the tubular element
    • F28F1/24Tubular elements and assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with projections, with recesses the means being only outside the tubular element and extending transversely
    • F28F1/32Tubular elements and assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with projections, with recesses the means being only outside the tubular element and extending transversely the means having portions engaging further tubular elements
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F28HEAT EXCHANGE IN GENERAL
    • F28DHEAT-EXCHANGE APPARATUS, NOT PROVIDED FOR IN ANOTHER SUBCLASS, IN WHICH THE HEAT-EXCHANGE MEDIA DO NOT COME INTO DIRECT CONTACT
    • F28D7/00Heat-exchange apparatus having stationary tubular conduit assemblies for both heat-exchange media, the media being in contact with different sides of a conduit wall
    • F28D7/0008Heat-exchange apparatus having stationary tubular conduit assemblies for both heat-exchange media, the media being in contact with different sides of a conduit wall the conduits for one medium being in heat conductive contact with the conduits for the other medium
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F28HEAT EXCHANGE IN GENERAL
    • F28FDETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
    • F28F21/00Constructions of heat-exchange apparatus characterised by the selection of particular materials
    • F28F21/04Constructions of heat-exchange apparatus characterised by the selection of particular materials of ceramic; of concrete; of natural stone
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F28HEAT EXCHANGE IN GENERAL
    • F28FDETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
    • F28F9/00Casings; Header boxes; Auxiliary supports for elements; Auxiliary members within casings
    • F28F9/007Auxiliary supports for elements
    • F28F9/013Auxiliary supports for elements for tubes or tube-assemblies
    • F28F9/0131Auxiliary supports for elements for tubes or tube-assemblies formed by plates
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F28HEAT EXCHANGE IN GENERAL
    • F28FDETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
    • F28F2275/00Fastening; Joining
    • F28F2275/02Fastening; Joining by using bonding materials; by embedding elements in particular materials

Definitions

  • the present invention relates to a heat exchanger which has at least one first tube for passing a first fluid and at least one second tube for passing a heat-dissipating second fluid, at least the first tube being made of a fluid-tight, corrosion and oxidation-resistant material a plurality of individual sub-elements formed support structure made of SiC-containing material is held in a bore of the sub-elements.
  • Such a heat exchanger is known from EP-A1 0 479 657.
  • This heat exchanger is constructed from a bundle of first tubes which are kept at a distance from one another by means of a support structure.
  • the supporting structure consists of individual panels.
  • a first fluid that is to be cooled is passed through the first tubes.
  • the entire support structure is surrounded by a second tube, ie a cladding tube, which has an inlet and outlet via which a second fluid is guided past the first tubes in order to dissipate the heat given off by the first tubes.
  • the first tubes and the supporting structure that fixes the first tubes are made of silicon carbide.
  • the support plates are first produced as green bodies with corresponding bores into which the first silicon carbide tubes are to be inserted. This is followed by sintering at temperatures between 1900 and 2500 ° C in order to firmly, ie immovably, connect the support plates to the first tubes. Thereby, that the individual first tubes are kept at a distance from one another, the second fluid can flow around them from all sides in order to dissipate the heat.
  • Such an arrangement brings with it problems in particular that if a single one of the first tubes is defective, the entire heat exchanger becomes unusable since it is practically impossible to separate its individual components.
  • the present invention is based on the object of creating a heat exchanger made of a corrosion and oxidation-resistant material which has a high mechanical strength, which withstands high temperature fluctuations and which has a high efficiency, i.e. enables a good heat exchange between the two fi luses, and which, despite the materials to be used, is also easy to assemble and enables easy replacement of such parts in relation to defective parts.
  • the supporting structure consists of stacked plate-like or disc-shaped partial elements made of one with carbon and / or ceramic fibers and interconnected via a SiC-containing connecting layer reinforced composite material and that at least between the first tube and the support structure, an expansion compensation layer made of ceramic material and / or carbon is arranged.
  • the heat exchanger according to the invention is characterized, on the one hand, by the fact that it is composed of individual, plate-shaped or disk-shaped partial elements which have cavities and are stacked one above the other and which are connected to one another via a silicon carbide-containing connecting layer.
  • the first tubes which carry the first fluid are then inserted into this support structure, in such a way that an expansion compensation layer made of ceramic material and / or carbon is arranged between the first tubes and the support structure.
  • This structure mechanically decouples the support structure and the tubes, at least those tubes that carry the first fluid. Only when a fluid is passed through the heat exchanger at high temperature, the first tubes expand, so that they are then firmly anchored to the support structure during operation of the heat exchanger.
  • the expansion compensation layer makes it possible to operate the heat exchanger at working temperatures that are even higher than 1400 ° C; In addition, an internal pressurization of the first tubes can be provided. The high working temperature and the high internal pressure lead to higher efficiency.
  • fluid in the description and the claims, this includes, in the sense of the statements, not only liquid media, but also gaseous media or mixtures of liquid and gaseous media which are passed through the tubes of the heat exchanger can also carry solid particles.
  • the supporting structure is made up of individual plates or disks
  • heat exchanger structures of any length can be built up from such individual plates or disks with prefabricated, standardized parts, with the corresponding cavities or bores into which the pipes which carry the fluids are inserted.
  • Due to the expansion compensation layer made of ceramic material and / or carbon it is achieved that the tubes, which are fixed in the operating structure of the heat exchanger, are released when the heat exchanger is not in operation, so that no stresses are stored at the transitions and it is also possible to remove individual, possibly defective pipes from the heat exchanger without special measures and to replace them with other pipes. Due to the design of the support structure and the tubes according to the invention, even when the tubes are subjected to internal pressure, these are only slightly stressed in train, which is of essential advantage for the safe and trouble-free operation of a heat exchanger.
  • the first tubes made of a fluid-tight, corrosion-resistant or oxidation-resistant material can be commercially available tubes, which are preferably formed from monolithic ceramics, from silicon carbide, silicon nitride, cordierite or mullite.
  • a monolithic ceramic will always be an advantage when gas tightness is the primary concern is required, while the first tubes made of silicon carbide and silicon nitride should be used when working under particularly high temperatures with low material expansion and high thermal shock loads.
  • Cordierite or mullite should be used for the first pipes if, on the one hand, work is carried out at high temperatures and, on the other hand, good resistance to oxidation and corrosion is required.
  • the materials specified above can also be used for the second tubes, which are used to conduct the second fluid through which the heat of the first fluid is removed in exchange.
  • the second fluid, which is conducted in a flow separate from the first fluid can be one that is precisely defined and thus does not place high demands on the second tubes, in contrast to the first tubes through which the fluid to be cooled is passed .
  • silicon carbide is used at least for the first tubes, this should preferably be a silicon-infiltrated silicon carbide (SiSiC) or a sintered silicon carbide (SSiC).
  • SiSiC silicon-infiltrated silicon carbide
  • SSiC sintered silicon carbide
  • pure silicon carbide powder is provided and cast as a layer. Such pipes are gas-tight and should be installed in the heat exchanger when working at very high temperatures.
  • this expansion compensation layer is preferably formed from a ceramic powder or from carbon powder.
  • Elongation compensation layers are furthermore suitable, which are essentially formed from ceramic and / or carbon fibers, which can also be filled with the respective materials in powder form.
  • the fibers in the area of the expansion compensation layer are given a preferred orientation such that they are oriented in the circumferential direction of the tubes.
  • Such expansion compensation layers can be produced easily and thinly.
  • Typical outside diameters of pipes around which the strain compensation layer is formed are in the range of 10 to 100 mm with a wall thickness depending on the diameter of 3 to 15 mm.
  • the expansion compensation layer should prevent thermal stresses in the area of the pipes and should therefore be in the order of 0.1 to 0.5 mm when the pipes have cooled down around them.
  • Boron nitride and / or aluminum nitride powders are particularly suitable for the above-mentioned ceramic powder in the area of the expansion compensation layer. Boron nitride powder and aluminum nitride powder are to be preferred if, on the one hand, high heat conduction, good mechanical decoupling between the pipes and the expansion compensation layer are required.
  • the fiber reinforcement in the sub-elements is formed from two-dimensional fabrics, fiber rovings or fabric tapes.
  • a carbon fiber reinforced composite material is used, the carbon fibers of which are embedded in silicon carbide. This silicon carbide is formed by infiltrating liquid silicon into a crack structure under the action of heat and reaction with carbon.
  • the partial elements from which the supporting structure is constructed should be oriented in the chamfering of their carbon and / or ceramic fibers in such a way that the highest possible heat flow between the first pipes, which carry the heated fluid, to the second pipes, which guide the cooling fluid or to the outside of the heat exchanger is guaranteed. This can also be achieved both by the choice of the fiber volume in the support structure and the type of fiber.
  • at least 50% of the fibers, preferably at least 90% of the fibers, in the partial elements should run parallel to the plate or disc plane of the partial elements designed as plates or discs, ie the fibers are radial to a large extent seen from the outside of the tube axes of the first and / or the second tubes, each oriented.
  • such fiber rovings or fabric tapes are wound, preferably in such a way that the individual layers extend radially around the axes of the pipes used later or the cavities in which the pipes are inserted. This results in a high strength in the circumferential direction of the sub-elements from which the supporting structure is built.
  • intermediate cavities can be formed during the construction of such wound partial elements, in particular if the bores in the individual partial elements are alternately wrapped with an endless band. The intermediate cavities then form in the area of the crossing fibers. Insert parts with high directional heat conduction can then be used in such intermediate cavities. Such insert parts can, however, also be inserted subsequently into cavities. Ceramic or ceramicized, carbon fiber reinforced composites are suitable for such insert parts. Insert parts made of silicon carbide which are embedded in the winding former are particularly preferred. Especially silicon carbide has the advantage that the same type of material can be used for the tubes or the fiber ceramic.
  • insert parts should be arranged so that their volume is dimensioned such that the highest possible, directed heat conduction takes place radially from the individual pipes which carry the working fluid to the pipes which carry the cooling fluid.
  • first and second tubes through which the first and the second fluid are guided can be introduced into the respective bores, which are defined in the partial elements and in the support structure formed therefrom.
  • a second tube is preferably arranged adjacent to a first tube.
  • a structure is preferred in which a first tube, through which the first fluid to be cooled is passed, is arranged centrally in the support structure, while the second tubes are distributed radially around the first tube through which the cooling fluid is passed.
  • a symmetrical arrangement of the second tubes around the central first tube is preferred, moreover, an arrangement such that the axes of the respective tubes run parallel to one another.
  • the heat exchanger can serve as a module unit, in which case the cross-sectional shape of the support structure (which then forms the module unit) is designed such that adjacent module units lie flat against one another.
  • a cross-sectional shape of the support structure as a polygon, preferably as a hexagon, is to be preferred, so that a further module unit is applied to the respective side edges of such a support structure.
  • the polygonal cross-sectional shape has the same side length, furthermore the polygon is a six-sided polygon (hexagon), six further module units can be created around a central module unit, so that a larger heat exchanger unit results. Additional module units of this type can then be added anywhere around this unit on the outside.
  • fixing grooves are preferably provided in the outer surfaces, into which fixing parts such as rods can be inserted. Such fixing parts should be a material of the same type as the supporting structure in order not to cause different thermal expansions.
  • the outer surface of the support structure can be provided with a corresponding protective layer, preferably one which is formed from silicon carbide and / or silicon dioxide and / or molybdenum disilicide.
  • the supporting structure is constructed from individual sub-elements.
  • Each sub-element can in turn consist of several individual plates.
  • partial elements or groups of partial elements with mutually different but nevertheless defined fiber orientations are provided, which are then assembled in a defined order to form the entire support structure and are connected by means of the silicon carbide-containing connecting layer.
  • FIGS. 1 to 4 show the step-by-step construction of a heat exchanger according to the invention in accordance with a first embodiment
  • FIG. 5 shows a section through a further heat exchanger which has a hexagonal cross-sectional structure
  • FIG. 6 shows a cross section through a further heat exchanger which is constructed from a plurality of heat exchanger modules corresponding to FIG. 5,
  • FIG. 10 shows a carrying structure comparable to that shown in FIG. 8, which is made of fiber rovings or fabric tapes, the individual fiber structures being indicated in the front area.
  • the heat exchanger as can be seen in the perspective illustration in FIG. 4, comprises a support structure 3 constructed from a plurality of plate-shaped partial elements 1 and 2.
  • this support structure 3 there are a central first tube 4 and further second ones distributed around the circumference of the central tube 4 Pipes 5 embedded. While the central, first tube 4 serves to pass a fluid to be cooled, a second fluid, which serves as cooling fluid, is passed through the second tube 5.
  • each sub-element 1, 2 is constructed from a composite material reinforced with carbon and ceramic fibers.
  • the sub-elements 1 and 2, as can be seen in FIG. 1, differ in each case by a different fiber orientation, as is indicated by the fiber course in the upper left corner of each sub-element 1, 2.
  • each sub-element can be constructed from individual plates with a small thickness.
  • a plate part or a partial element 1, 2 is produced from a porous, carbon-fiber-reinforced carbon material (C / C) with so-called long fibers, or fibers that are endless, in an orthotropic or quasi-isotropic orientation to the plate plane.
  • Such fiberboard are then first assembled into a sub-element 1, for example by gluing with a carbon-rich paste.
  • the individual sub-elements 1, 2 are then also glued to one another using this connection technique, so that a preform results, as shown in FIG.
  • bores 6 are made, which is possible with relatively little effort, since this preform can be easily machined using conventional drilling techniques.
  • This pre-body is a porous structure, the pores being able to be formed in a defined manner if necessary.
  • a technique is preferably used, the individual carbon fibers being embedded in a carbon-rich polymer, such a defined crack structure being able to be generated and defined in a pyrolysis manner.
  • the pores or the crack structure of this supporting structure of the C / C body is then infiltrated with liquid silicon, which is converted to silicon carbide under the action of heat at temperatures in the range from 1410 ° C. to 1700 ° C.
  • the cross sections of the bores 6 can be set in a defined manner.
  • a silicon carbide connecting layer is formed in the area of the sliding surfaces of the partial elements 1, 2 which are glued together, so that the adhesive layer is replaced by a silicon carbide layer and a homogeneous, high-strength supporting structure 3 also results in the area of the joint of individual sub-elements 1, 2.
  • the first and second tubes 4 and 5 to be used are dimensioned in accordance with the bore cross-sections, but in such a way that their diameter is slightly smaller than the free bore diameter, so that an intermediate space arises when the tube is inserted. These gaps serve as an expansion compensation area, which is filled with an expansion compensation layer 8 made of ceramic material and / or carbon.
  • the expansion compensation layer 8 can be formed by inserting a layer of ceramic and / or carbon fibers or foils before inserting the tubes into the bores. Then the pipes are inserted so that they fill the remaining space while maintaining a defined gap.
  • the first and second tubes are first inserted into the bores and the intermediate space is largely filled with a ceramic powder material.
  • the first and second tubes 4, 5 are fixed in the support structure 3, but are not embedded in a force-fitting and form-locking manner so that they would be immovable.
  • FIG. 4 While a heat exchanger is shown schematically in FIG. 4, which has a square structure transverse to the longitudinal extension of the first and second tubes 4, 5, a heat exchanger module is shown in FIG. 5 and in FIG. 9, which has a hexagonal cross section with the same side length having.
  • a heat exchanger is constructed as explained above with reference to FIGS. 1 to 4, FIG. 7 again showing a single partial element 1, 2 of such a support structure 3.
  • FIG. 8 Several such sub-elements 1, 2 are then glued to one another, as indicated in FIG. 8 with the adhesive or connecting layers 7.
  • the tubes 4, 5 are then inserted into the bores, again with a ceramic intermediate layer which serves as an expansion layer 8, as indicated in FIG. 5.
  • heat exchangers of any length can be produced, for which standardized parts are used.
  • a central heat exchanger unit further module units are assigned a corresponding cross-sectional shape of each side surface, so that the middle, central heat exchanger module unit is completely surrounded by outer module units.
  • fixing grooves 9 are formed, for example with a semicircular cross section, which then complement one another in the construction of the heat exchanger according to FIG. 6 with the grooves of adjacent heat exchanger modules, in which, for example, fixing pins or fixing rods 10 can be used.
  • the individual module units according to FIG. 6 can be connected using suitable connection techniques, for which purpose silicon carbide layers are suitable.
  • the respective pipes 4, 5 of the module units of FIG. 6 can be connected to one another in a suitable manner in terms of flow, so that two flow systems result, the first flow system comprising the first pipes 4 (light cross section in FIG. 6), while the second pipe system (second Pipes 5 - indicated darkly in Figure 6) forms the second pipe system.
  • the fluid to be cooled is passed through the first pipe system, while the second pipe system receives the cooling fluid.
  • FIG. 6 other geometric structures can be produced with module units as shown in FIG. 5, for example heat exchangers that have a relatively large, medium cavity or complex heat exchanger structures, such as wall surfaces, in their Length and height are variable in order to adapt them to the requirements.
  • heat exchangers that have a relatively large, medium cavity or complex heat exchanger structures, such as wall surfaces, in their Length and height are variable in order to adapt them to the requirements.
  • FIG. 10 shows a support structure 3 which is wound from fiber rovings or fabric strips.
  • this support structure is wound in a building-up manner in the Z direction, in that the individual fiber layers are alternately around the individual bores 6, for which placeholders (not shown) can be used during the winding process , wrapped.
  • the crosswise course essentially around the corresponding placeholder for the inner tube 4 to be used results in a high-strength structure.
  • the fibers or fiber tapes are placed in such a way that they each run to opposite placeholders and are then guided to the respectively adjacent placeholder.
  • the inner tube 4 is formed or the bore 6 for the inner tube 4 adjoining triangular cavities, into which a corresponding insert 11 made of a good heat-conducting material, for example a fiber ceramic, can then be inserted.
  • the expansion compensation layer can first be arranged around shaped placeholder bodies before the actual winding process takes place.
  • the stretch compensation layer can also be built up during the winding process by applying fibers radially around a corresponding core or area to the respective prefabricated first and second tubes 4, 5, which are not shown in detail in FIG. 10, however.

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  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Ceramic Engineering (AREA)
  • Geometry (AREA)
  • Heat-Exchange Devices With Radiators And Conduit Assemblies (AREA)

Abstract

The invention relates to a heat exchanger comprising at least one first tube (4) for conducting a first fluid and at least one second tube (5) for conducting a heat dissipating fluid. At least the first tube (4) which is made of a fluid-tight corrosion and oxidation resistant substance is held in a supporting structure (3) comprising several individual elements containing SiC in a bore hole of said partial elements (1,2). The inventive heat exchanger is characterized in that the supporting structure (3) is composed of flat or disc shaped partial elements (1,2) which are made of a reinforced carbon and/or ceramic composite material, stacked on top of each other and joined to each other by a SiC coating, and that a ceramic and/or carbon extension compensating layer (8) is arranged at least between the first tube (4) and the supporting structure (3).

Description

P A T E N T A N M E L D U N G P A T E N T A N M E L D U N G
"Wärmetauscher""Heat exchanger"
Die vorliegende Erfindung betrifft einen Wärmetauscher, der mindestens ein erstes Rohr zum Hindurchleiten eines ersten Fluids und mindestens ein zweites Rohr zum Hindurchleiten eines Wärme abführenden zweiten Fluids aufweist, wobei zumindest das erste Rohr, aus einem fluiddichten, korrosions- und oxidationsbeständigen Werkstoff, in einer aus mehreren einzelnen Teilelementen gebildeten Tragstruktur aus SiC-haltigem Werkstoff in einer Bohrung der Teilelemente gehalten ist.The present invention relates to a heat exchanger which has at least one first tube for passing a first fluid and at least one second tube for passing a heat-dissipating second fluid, at least the first tube being made of a fluid-tight, corrosion and oxidation-resistant material a plurality of individual sub-elements formed support structure made of SiC-containing material is held in a bore of the sub-elements.
Ein derartiger Wärmetauscher ist aus der EP-A1 0 479 657 bekannt. Dieser Wärmetauscher ist aus einem Bündel erster Rohre, die auf Abstand zueinander mittels einer Tragstruktur gehalten werden, aufgebaut. Die Tragstruktur besteht aus einzelnen Platten. Durch die ersten Rohre wird ein erstes Fluid hindurchgeführt, das gekühlt werden soll. Die gesamte Tragstruktur ist von einem zweiten Rohr, d.h. einem Hüllrohr, umgeben, das einen Zu- und Ablauf aufweist, über die ein zweites Fluid an den ersten Rohren vorbeigeführt wird, um die von den ersten Rohren abgegebene Wärme abzuführen. Die ersten Rohre sowie die Tragstruktur, die die ersten Rohre fixiert, bestehen aus Siiiciumcarbid. Um die Tragstruktur mit den ersten Rohren aufzubauen, werden die Trageplatten zunächst als Grünkörper hergestellt mit entsprechenden Bohrungen, in die die ersten Rohre aus Siiiciumcarbid eingesteckt werden sollen. Danach erfolgt eine Sinterung bei Temperaturen zwischen 1900 bis 2500°C, um die Trageplatten mit den ersten Rohren fest, d.h. unverrückbar, zu verbinden. Dadurch, daß die einzelnen ersten Rohre mit Abstand zueinander gehalten sind, können sie gut von allen Seiten von dem zweiten Fluid umströmt werden, um die Wärme abzuführen. Eine solche Anordnung bringt Probleme insbesondere dann mit sich, daß, falls ein einzelnes der ersten Rohre defekt ist, der gesamte Wärmetauscher unbrauchbar wird, da eine Trennung seiner einzelnen Bauteile praktisch nicht möglich ist.Such a heat exchanger is known from EP-A1 0 479 657. This heat exchanger is constructed from a bundle of first tubes which are kept at a distance from one another by means of a support structure. The supporting structure consists of individual panels. A first fluid that is to be cooled is passed through the first tubes. The entire support structure is surrounded by a second tube, ie a cladding tube, which has an inlet and outlet via which a second fluid is guided past the first tubes in order to dissipate the heat given off by the first tubes. The first tubes and the supporting structure that fixes the first tubes are made of silicon carbide. In order to build the support structure with the first tubes, the support plates are first produced as green bodies with corresponding bores into which the first silicon carbide tubes are to be inserted. This is followed by sintering at temperatures between 1900 and 2500 ° C in order to firmly, ie immovably, connect the support plates to the first tubes. Thereby, that the individual first tubes are kept at a distance from one another, the second fluid can flow around them from all sides in order to dissipate the heat. Such an arrangement brings with it problems in particular that if a single one of the first tubes is defective, the entire heat exchanger becomes unusable since it is practically impossible to separate its individual components.
Ausgehend von dem vorstehend angegebenen Stand der Technik liegt nun der vorliegenden Erfindung die Aufgabe zugrunde, einen Wärmetauscher aus einem korrosions- und oxidationsbeständigen Werkstoff zu schaffen, der eine hohe mechanische Festigkeit aufweist, der hohen Temperaturwechsel∑ykien standhält, der einen hohen Wirkungsgrad, d.h. einen guten Wärmeaustausch zwischen den beiden Fiui- den ermöglicht, und der darüberhinaus, trotz der einzusetzenden Werkstoffe, einfach aufbaubar ist und in Bezug auf defekte Teile einen leichten Austausch solcher Teile ermöglicht.Starting from the above-mentioned prior art, the present invention is based on the object of creating a heat exchanger made of a corrosion and oxidation-resistant material which has a high mechanical strength, which withstands high temperature fluctuations and which has a high efficiency, i.e. enables a good heat exchange between the two fi luses, and which, despite the materials to be used, is also easy to assemble and enables easy replacement of such parts in relation to defective parts.
Gelöst wird diese Aufgabe, ausgehend von einem Wärmetauscher mit den Merkmalen des Oberbegriffs des Anspruchs 1 , dadurch, daß die Tragstruktur aus aufeinandergestapelten und über eine SiC-haltige Verbindungsschicht miteinander verbundenen platten- oder scheibenförmigen Teilelementen aus einem mit Kohlenstoff- und/oder Keramik-Fasern verstärkten Verbundwerkstoff aufgebaut ist und daß zumindest zwischen dem ersten Rohr und der Tragstruktur eine Dehnungsausgleichsschicht aus keramischem Werkstoff und/oder Kohlenstoff angeordnet ist.This object is achieved, starting from a heat exchanger with the features of the preamble of claim 1, characterized in that the supporting structure consists of stacked plate-like or disc-shaped partial elements made of one with carbon and / or ceramic fibers and interconnected via a SiC-containing connecting layer reinforced composite material and that at least between the first tube and the support structure, an expansion compensation layer made of ceramic material and / or carbon is arranged.
Der erfindungsgemäße Wärmetauscher ist zum einen dadurch charakterisiert, daß er aus einzelnen, platten- oder scheibenförmigen Teilelementen aufgebaut ist, die Hohlräume aufweisen und übereinandergestapelt sind und die über eine Siliciumcar- bid-haltige Verbindungsschicht miteinander verbunden sind. In diese so gebildete Tragstruktur werden dann die ersten Rohre, die das erste Fluid führen, eingesteckt, derart, daß zwischen den ersten Rohren und der Tragstruktur eine Dehnungsausgleichsschicht aus keramischem Werkstoff und/oder Kohlenstoff angeordnet ist. Durch diesen Aufbau sind die Tragstruktur und die Rohre, zumindest diejenigen Rohre, die das erste Fluid führen, mechanisch entkoppelt. Erst dann, wenn ein Fluid mit hoher Temperatur durch den Wärmetauscher hindurchgeführt wird, erfolgt eine Ausdehnung der ersten Rohre, so daß diese dann, im Betrieb des Wärmetauschers, fest mit der Tragstruktur verankert sind. Durch die Dehnungsausgleichsschicht ist es möglich, den Wärmetauscher bei Arbeitstemperaturen zu betreiben, die sogar höher als 1400°C liegen; außerdem kann eine Innendruckbeaufschlagung der ersten Rohre vorgesehen werden. Die hohe Arbeitstemperatur und der hohe Innendruck führen zu einem höheren Wirkungsgrad.The heat exchanger according to the invention is characterized, on the one hand, by the fact that it is composed of individual, plate-shaped or disk-shaped partial elements which have cavities and are stacked one above the other and which are connected to one another via a silicon carbide-containing connecting layer. The first tubes which carry the first fluid are then inserted into this support structure, in such a way that an expansion compensation layer made of ceramic material and / or carbon is arranged between the first tubes and the support structure. This structure mechanically decouples the support structure and the tubes, at least those tubes that carry the first fluid. Only when a fluid is passed through the heat exchanger at high temperature, the first tubes expand, so that they are then firmly anchored to the support structure during operation of the heat exchanger. The expansion compensation layer makes it possible to operate the heat exchanger at working temperatures that are even higher than 1400 ° C; In addition, an internal pressurization of the first tubes can be provided. The high working temperature and the high internal pressure lead to higher efficiency.
Soweit in der Beschreibung und den Ansprüchen der Begriff "Fluid" verwendet wird, fallen hierunter, im Sinne der Ausführungen, nicht nur flüssige Medien, sondern auch gasförmige Medien oder Gemische aus flüssigen und gasförmigen Medien, die durch die Rohre des Wärmetauschers hindurchgeführt werden, die auch Feststoffpartikel mitführen können.Insofar as the term "fluid" is used in the description and the claims, this includes, in the sense of the statements, not only liquid media, but also gaseous media or mixtures of liquid and gaseous media which are passed through the tubes of the heat exchanger can also carry solid particles.
Da die Tragstruktur aus einzelnen Platten oder Scheiben aufgebaut ist, können mit vorgefertigten, standardisierten Teilen beliebig lange Wärmetauscherstrukturen aus solchen einzelnen Platten oder Scheiben aufgebaut werden mit den entsprechenden Hohlräumen bzw. Bohrungen, in die die Rohre, die die Fluide führen, eingesteckt werden. Aufgrund der Dehnungsausgleichsschicht aus keramischem Werkstoff und/oder Kohlenstoff wird erreicht, daß die Rohre, die im Betriebszustand des Wärmetauschers fest in der Tragstruktur fixiert sind, jeweils freigegebenen werden, wenn der Wärmetauscher außer Betrieb ist, so daß keine Spannungen an den Übergängen gespeichert werden und es auch möglich ist, einzelne, eventuell defekte Rohre dem Wärmetauscher, ohne besondere Maßnahmen, zu entnehmen und durch andere Rohre zu ersetzen. Durch die erfindungsgemäße Ausbildung der Tragstruktur und der Rohre werden auch bei Innendruckbelastungen der Rohre diese nur gering auf Zug beansprucht, was für einen sicheren und störungsfreien Betrieb eines Wärmetauschers von wesentlichem Vorteil ist.Since the supporting structure is made up of individual plates or disks, heat exchanger structures of any length can be built up from such individual plates or disks with prefabricated, standardized parts, with the corresponding cavities or bores into which the pipes which carry the fluids are inserted. Due to the expansion compensation layer made of ceramic material and / or carbon it is achieved that the tubes, which are fixed in the operating structure of the heat exchanger, are released when the heat exchanger is not in operation, so that no stresses are stored at the transitions and it is also possible to remove individual, possibly defective pipes from the heat exchanger without special measures and to replace them with other pipes. Due to the design of the support structure and the tubes according to the invention, even when the tubes are subjected to internal pressure, these are only slightly stressed in train, which is of essential advantage for the safe and trouble-free operation of a heat exchanger.
Die ersten Rohre aus einem fluiddichten, korrosions- oder oxidationsbeständigen Werkstoff können handelsübliche Rohre sein, die vorzugsweise aus monolithischer Keramik, aus Siiiciumcarbid, Siliciumnitrid, Cordierit oder Mullit gebildet sind. Eine monolithische Keramik wird immer dann von Vorteil sein, wenn Gasdichtheit primär gefordert ist, während erste Rohre aus Siiiciumcarbid und Siliciumnitrid dann eingesetzt werden sollten, wenn unter besonders hohen Temperaturen bei niedriger Materialausdehnung und hohen Temperaturwechselbeanspruchungen gearbeitet wird. Cordierit oder Mullit sollten dann für die ersten Rohre verwendet werden, wenn einerseits unter hohen Temperaturen gearbeitet wird, andererseits eine gute Oxidations- und Korrosionsbeständigkeit gefordert ist.The first tubes made of a fluid-tight, corrosion-resistant or oxidation-resistant material can be commercially available tubes, which are preferably formed from monolithic ceramics, from silicon carbide, silicon nitride, cordierite or mullite. A monolithic ceramic will always be an advantage when gas tightness is the primary concern is required, while the first tubes made of silicon carbide and silicon nitride should be used when working under particularly high temperatures with low material expansion and high thermal shock loads. Cordierite or mullite should be used for the first pipes if, on the one hand, work is carried out at high temperatures and, on the other hand, good resistance to oxidation and corrosion is required.
Die vorstehend angegebenen Materialien können auch für die zweiten Rohre eingesetzt werden, die zum Hindurchleiten des zweiten Fluids, über das die Wärme des ersten Fluids im Austausch abgeführt wird, dienen. Allerdings kann das zweite Fluid, das strömungsmäßig getrennt von dem ersten Fluid geführt wird, ein solches sein, das genau definiert wird und somit keine hohen Ansprüche an die zweiten Rohre stellt, im Gegensatz zu den ersten Rohren, durch die das zu kühlende Fluid hindurchgeführt wird.The materials specified above can also be used for the second tubes, which are used to conduct the second fluid through which the heat of the first fluid is removed in exchange. However, the second fluid, which is conducted in a flow separate from the first fluid, can be one that is precisely defined and thus does not place high demands on the second tubes, in contrast to the first tubes through which the fluid to be cooled is passed .
Falls zumindest für die ersten Rohre Siiiciumcarbid verwendet wird, so sollte es sich hierbei vorzugsweise um ein Siiicium-infiltriertes Siiiciumcarbid (SiSiC) oder ein gesintertes Siiiciumcarbid (SSiC) handeln. Zur Fertigung der Rohre aus gesintertem Siiiciumcarbid wird reines Siliciumcarbidpulver als Schiicker bereitgestellt und gegossen. Solche Rohre sind gasdicht und sollten dann, wenn unter sehr hohen Temperaturen gearbeitet wird, in den Wärmetauscher eingebaut werden.If silicon carbide is used at least for the first tubes, this should preferably be a silicon-infiltrated silicon carbide (SiSiC) or a sintered silicon carbide (SSiC). To manufacture the pipes from sintered silicon carbide, pure silicon carbide powder is provided and cast as a layer. Such pipes are gas-tight and should be installed in the heat exchanger when working at very high temperatures.
Um die Dehnungsausgleichsschicht definiert zu bilden, darüberhinaus im Bereich dieser Schicht einen guten Wärmeübergang zu der Tragstruktur und damit zu den zweiten Rohren hin zu gewährleisten, wird diese Dehnungsausgleichsschicht bevorzugt aus einem keramischen Pulver oder aus Kohlenstoffpulver gebildet. Weiterhin eignen sich Dehnungsausgleichsschichten, die im wesentlichen aus Keramik- und/oder Kohlenstoff-Fasern gebildet sind, die darüberhinaus noch mit den jeweiligen Materialien in Pulverform gefüllt sein können. Den Fasern im Bereich der Dehnungsausgleichsschicht wird eine bevorzugte Orientierung gegeben derart, daß sie in Um- fangsrichtung der Rohre orientiert sind. Solche Dehnungsausgleichsschichten können einfach und dünn hergstellt werden. Typische Außendurchmesser von Rohren, um die die Dehnungsausgleichsschicht herum gebildet wird, liegen im Bereich von 10 bis 100 mm mit einer Wandstärke in Abhängigkeit vom Durchmesser von 3 bis 15 mm. Die Dehnungsausgleichsschicht sollte thermische Spannungen im Bereich der Rohre verhindern und daher, in der Größenordnung von 0,1 bis 0,5 mm im abgekühlten Zustand der Rohre um diese herum liegen.In order to form the expansion compensation layer in a defined manner, and in addition to ensure good heat transfer in the region of this layer to the supporting structure and thus to the second tubes, this expansion compensation layer is preferably formed from a ceramic powder or from carbon powder. Elongation compensation layers are furthermore suitable, which are essentially formed from ceramic and / or carbon fibers, which can also be filled with the respective materials in powder form. The fibers in the area of the expansion compensation layer are given a preferred orientation such that they are oriented in the circumferential direction of the tubes. Such expansion compensation layers can be produced easily and thinly. Typical outside diameters of pipes around which the strain compensation layer is formed are in the range of 10 to 100 mm with a wall thickness depending on the diameter of 3 to 15 mm. The expansion compensation layer should prevent thermal stresses in the area of the pipes and should therefore be in the order of 0.1 to 0.5 mm when the pipes have cooled down around them.
Für das vorstehend angesprochene keramische Pulver im Bereich der Dehnungsausgleichsschicht eignen sich insbesondere Bornitrid- und/oder Aluminiumnitrid-Pulver. Bornitrid-Pulver und Aluminiumnitrid-Pulver sind dann zu bevorzugen, wenn eine hohe Wärmeleitung einerseits, eine gute mechanische Entkopplung zwischen den Rohren und der Dehnungsausgleichsschicht gefordert sind.Boron nitride and / or aluminum nitride powders are particularly suitable for the above-mentioned ceramic powder in the area of the expansion compensation layer. Boron nitride powder and aluminum nitride powder are to be preferred if, on the one hand, high heat conduction, good mechanical decoupling between the pipes and the expansion compensation layer are required.
Um eine hohe Festigkeit und gute Wärmeleitung zu erreichen, wird die Faserverstärkung in den Teilelementen aus zweidimensionalen Geweben, Faser-Rovings oder Gewebe-Bändern gebildet. Um eine Tragstruktur, aufgebaut aus den einzelnen Teilelementen, zu erreichen, die sehr hohen Temperaturen standhält und eine sehr hohe Festigkeit aufweist, wird ein Kohlenstoff-faserverstärkter Verbundwerkstoff eingesetzt, dessen Kohlenstoff-Fasern in Siiiciumcarbid eingebettet werden. Dieses Siiiciumcarbid wird durch Infiltrieren von flüssigem Silicium in eine Rißstruktur unter Wärmeeinwirkung und Reaktion mit Kohlenstoff gebildet.In order to achieve high strength and good heat conduction, the fiber reinforcement in the sub-elements is formed from two-dimensional fabrics, fiber rovings or fabric tapes. In order to achieve a support structure, built up from the individual sub-elements, which withstands very high temperatures and has a very high strength, a carbon fiber reinforced composite material is used, the carbon fibers of which are embedded in silicon carbide. This silicon carbide is formed by infiltrating liquid silicon into a crack structure under the action of heat and reaction with carbon.
Die Teilelemente, aus denen die Tragstruktur aufgebaut ist, sollten in dem Fasen/erlauf ihrer Kohlenstoff- und/oder Keramik-Fasern so orientiert werden, daß ein möglichst hoher Wärmefluß zwischen den ersten Rohren, die das erwärmte Fluid führen, zu den zweiten Rohren, die das Kühlfluid führen bzw. zu der Außenseite des Wärmetauschers hin, gewährleistet ist. Dies kann darüberhinaus sowohl durch die Wahl des Faservolumens in der Tragstruktur als auch des Fasertyps erreicht werden. Um diesen Wärmefluß über die Faserorientierung zu erreichen, sollten mindestens 50% der Fasern, vorzugsweise mindestens 90% der Fasern, in den Teilelementen parallel zur Platten- oder Scheibenebene der als Platten oder Scheiben ausgebildeten Teilelemente verlaufen, d.h. die Fasern sind mit einem hohen Anteil radial nach außen von den Rohrachsen der ersten und/oder der zweiten Rohre aus gesehen, jeweils orientiert. Für einen einfachen Aufbau werden solche Faser-Rovings oder Gewebe-Bänder gewickelt, vorzugsweise derart, daß sich die einzelnen Lagen radial um die Achsen der später eingesetzten Rohre bzw. der Hohlräume, in die die Rohre eingesetzt werden, erstrecken. Hierdurch ergibt sich in Umfangsrichtung eine hohe Festigkeit der Teilelemente, aus denen die Tragstruktur aufgebaut wird.The partial elements from which the supporting structure is constructed should be oriented in the chamfering of their carbon and / or ceramic fibers in such a way that the highest possible heat flow between the first pipes, which carry the heated fluid, to the second pipes, which guide the cooling fluid or to the outside of the heat exchanger is guaranteed. This can also be achieved both by the choice of the fiber volume in the support structure and the type of fiber. In order to achieve this heat flow via the fiber orientation, at least 50% of the fibers, preferably at least 90% of the fibers, in the partial elements should run parallel to the plate or disc plane of the partial elements designed as plates or discs, ie the fibers are radial to a large extent seen from the outside of the tube axes of the first and / or the second tubes, each oriented. For a simple construction, such fiber rovings or fabric tapes are wound, preferably in such a way that the individual layers extend radially around the axes of the pipes used later or the cavities in which the pipes are inserted. This results in a high strength in the circumferential direction of the sub-elements from which the supporting structure is built.
Während des Aufbaus solcher gewickelten Teilelemente können definierte Zwischenhohlräume ausgebildet werden, insbesondere dann, wenn die Bohrungen in den einzelnen Teilelementen wechselweise mit einem endlosen Band umwickelt werden. Die Zwischenhohlräume bilden sich dann im Bereich der sich kreuzenden Fasern. In solche Zwischenhohiräume können dann Einsatzteile mit hoher gerichteter Wärmeleitung eingesetzt werden. Solche Einsatzteile können aber auch nachträglich in die Teilelemente eingebrachte Hohlräume eingesetzt werden. Für solche Einsatzteile eignen sich keramische oder keramisierte, kohlenstoff-faserverstärkte Verbundstoffe. Besonders bevorzugt sind Einsatzteile aus Siiiciumcarbid, die in den Wickelkörper eingebettet werden. Gerade Siiiciumcarbid bringt den Vorteil mit sich, daß artgleiches Material zu den Rohren bzw. der Faserkeramik verwendet werden kann.Defined intermediate cavities can be formed during the construction of such wound partial elements, in particular if the bores in the individual partial elements are alternately wrapped with an endless band. The intermediate cavities then form in the area of the crossing fibers. Insert parts with high directional heat conduction can then be used in such intermediate cavities. Such insert parts can, however, also be inserted subsequently into cavities. Ceramic or ceramicized, carbon fiber reinforced composites are suitable for such insert parts. Insert parts made of silicon carbide which are embedded in the winding former are particularly preferred. Especially silicon carbide has the advantage that the same type of material can be used for the tubes or the fiber ceramic.
Solche Einsatzteile sollten aber so verteilt angeordnet und in ihrem Volumen dimensioniert werden, daß eine möglichst hohe, gerichtete Wärmeleitung radial von den einzelnen Rohren, die das Arbeitsfluid führen, zu den Rohren, die das Kühlfuid führen hin, erfolgt.However, such insert parts should be arranged so that their volume is dimensioned such that the highest possible, directed heat conduction takes place radially from the individual pipes which carry the working fluid to the pipes which carry the cooling fluid.
Wie bereits vorstehend erwähnt ist, können in die jeweiligen Bohrungen, die definiert in den Teilelementen und in der daraus gebildeten Tragstruktur eingebracht sind, die ersten und zweiten Rohre eingeführt werden, durch die das erste und das zweite Fluid geführt wird. Bevorzugt wird jeweils benachbart zu einem ersten Rohr jeweils ein zweites Rohr angeordnet. Um einen hohen Wirkungsgrad im Wärmeaustausch zu erreichen, ist allerdings ein Aufbau zu bevorzugen, bei dem ein erstes Rohr, durch das das zu kühlende erste Fluid hindurchgeführt wird, zentral in der Tragstruktur angeordnet ist, während die zweiten Rohre radial um das erste Rohr verteilt werden, durch die das Kühl-Fluid hindurchgeführt wird. Zu bevorzugen ist eine symmetrische Anordnung der zweiten Rohre um das zentrale erste Rohr herum, darüberhinaus eine Anordnung derart, daß die Achsen der jeweiligen Rohre parallel zueinander verlaufen.As already mentioned above, the first and second tubes through which the first and the second fluid are guided can be introduced into the respective bores, which are defined in the partial elements and in the support structure formed therefrom. A second tube is preferably arranged adjacent to a first tube. In order to achieve a high efficiency in heat exchange, however, a structure is preferred in which a first tube, through which the first fluid to be cooled is passed, is arranged centrally in the support structure, while the second tubes are distributed radially around the first tube through which the cooling fluid is passed. A symmetrical arrangement of the second tubes around the central first tube is preferred, moreover, an arrangement such that the axes of the respective tubes run parallel to one another.
Der Wärmetauscher, wie er vorstehend in seinen verschiedenen Ausführungsformen beschrieben ist, kann als Moduleinheit dienen, wobei dann die Querschnittsform der Tragstruktur (die dann die Moduleinheit bildet), so ausgeführt ist, daß aufeinander- grenzende Moduleinheiten flächig aneinanderliegen. Hierzu ist eine Querschnittsform der Tragstruktur als Polygon, vorzugsweise als Hexagon, zu bevorzugen, so daß an die jeweiligen Seitenkanten einer solchen Tragstruktur jeweils eine weitere Moduleinheit angelegt wird. Falls die polygonförmige Querschnittsform eine gleiche Seitenlänge aufweist, darüberhinaus das Polygon ein sechsseitiges Polygon (Hexagon) ist, können um eine zentrale Moduleinheit sechs weitere Moduleinheiten angelegt werden, so daß sich eine größere Wärmeaustauschereinheit ergibt. Weitere solcher Moduleinheiten können dann beliebig um diese Einheit herum an der Außenseite angefügt werden. Für die Verbindung der einzelnen Moduleinheiten sind vorzugsweise in den Außenoberflächen Fixiernuten vorgesehen, in die Fixierteile wie Stäbe, eingelegt werden können. Solche Fixierteile sollten ein mit der Tragstruktur artgleiches Material sein, um keine unterschiedlichen Wärmedehnungen hervorzurufen.The heat exchanger, as described above in its various embodiments, can serve as a module unit, in which case the cross-sectional shape of the support structure (which then forms the module unit) is designed such that adjacent module units lie flat against one another. For this purpose, a cross-sectional shape of the support structure as a polygon, preferably as a hexagon, is to be preferred, so that a further module unit is applied to the respective side edges of such a support structure. If the polygonal cross-sectional shape has the same side length, furthermore the polygon is a six-sided polygon (hexagon), six further module units can be created around a central module unit, so that a larger heat exchanger unit results. Additional module units of this type can then be added anywhere around this unit on the outside. For the connection of the individual module units, fixing grooves are preferably provided in the outer surfaces, into which fixing parts such as rods can be inserted. Such fixing parts should be a material of the same type as the supporting structure in order not to cause different thermal expansions.
Um den Wärmetauscher gegen Oxidation oder Korrosion zu schützen, kann die Außenoberfläche der Tragstruktur mit einer entsprechenden Schutzschicht versehen werden, vorzugsweise einer solchen, die aus Siiiciumcarbid und/oder Siliciumdioxid und/oder Molybdändisilizid gebildet ist.In order to protect the heat exchanger against oxidation or corrosion, the outer surface of the support structure can be provided with a corresponding protective layer, preferably one which is formed from silicon carbide and / or silicon dioxide and / or molybdenum disilicide.
Wie eingangs beschrieben ist, wird die Tragstruktur aus einzelnen Teilelementen aufgebaut. Jedes Teilelement wiederum kann aus mehreren Einzelplatten bestehen. Um in Richtung der Längsachse des Wärmetauschers gesehen die Wärmeverteilung im Bereich der Tragstruktur zu homogenisieren und eventuelle Wärmegradienten ab- zubauen, werden Teilelemente oder Gruppen aus Teilelementen mit zueinander unterschiedlichen, allerdings dennoch definierten Faserorientierungen bereitgestellt, die dann in einer definierten Reihenfolge zu der gesamten Tragstruktur zusammengesetzt und mittels der Siliciumcarbid-haltigen Verbindungsschicht verbunden werden. Weitere Einzelheiten und Merkmale der Erfindung ergeben sich aus der Beschreibung von Ausführungsbeispielen anhand der Zeichnung. In der Zeichnung zeigtAs described at the beginning, the supporting structure is constructed from individual sub-elements. Each sub-element can in turn consist of several individual plates. In order to homogenize the heat distribution in the area of the support structure in the direction of the longitudinal axis of the heat exchanger and to reduce any thermal gradients, partial elements or groups of partial elements with mutually different but nevertheless defined fiber orientations are provided, which are then assembled in a defined order to form the entire support structure and are connected by means of the silicon carbide-containing connecting layer. Further details and features of the invention result from the description of exemplary embodiments with reference to the drawing. In the drawing shows
Figuren 1 bis 4 den schrittweisen Aufbau eines erfindungsgemäßen Wärmetauschers entsprechend einer ersten Ausführungsform,FIGS. 1 to 4 show the step-by-step construction of a heat exchanger according to the invention in accordance with a first embodiment,
Figur 5 einen Schnitt durch einen weiteren Wärmetauscher, der eine hexagonale Querschnittsstruktur aufweist,FIG. 5 shows a section through a further heat exchanger which has a hexagonal cross-sectional structure,
Figur 6 einen Querschnitt durch einen weiteren Wärmetauscher, der aus mehreren Wärmetauscher-Modulen entsprechend Figur 5 aufgebaut ist,6 shows a cross section through a further heat exchanger which is constructed from a plurality of heat exchanger modules corresponding to FIG. 5,
Figuren 7 bis 9 den Wärmetauscher, wie er im Schnitt in Figur 5 dargestellt ist, in perspektivischer Darstellung in drei Verfahrensschritten seiner Herstellung, undFigures 7 to 9, the heat exchanger, as shown in section in Figure 5, in perspective in three process steps of its manufacture, and
Figur 10 eine Tragestruktur vergleichbar mit derjenigen, die in Figur 8 dargestellt ist, die aus Faser-Rovings oder Gewebebändern gefertigt ist, wobei die einzelnen Faserstrukturen im vorderen Bereich angedeutet dargestellt sind.FIG. 10 shows a carrying structure comparable to that shown in FIG. 8, which is made of fiber rovings or fabric tapes, the individual fiber structures being indicated in the front area.
Der Wärmetauscher, wie er in der perspektivischen Darstellung der Figur 4 zu sehen ist, umfaßt eine aus mehreren plattenförmigen Teilelementen 1 und 2 aufgebaute Tragstruktur 3. In dieser Tragstruktur 3 sind ein zentrales erstes Rohr 4 und um den Umfang des zentralen Rohrs 4 verteilt weitere zweite Rohre 5 eingebettet. Während das zentrale, erste Rohr 4 dazu dient, ein zu kühlendes Fluid hindurchzuführen, wird durch das zweite Rohr 5 ein zweites Fluid, das als Kühlfluid dient, geleitet.The heat exchanger, as can be seen in the perspective illustration in FIG. 4, comprises a support structure 3 constructed from a plurality of plate-shaped partial elements 1 and 2. In this support structure 3 there are a central first tube 4 and further second ones distributed around the circumference of the central tube 4 Pipes 5 embedded. While the central, first tube 4 serves to pass a fluid to be cooled, a second fluid, which serves as cooling fluid, is passed through the second tube 5.
Um einen solchen Wärmetauscher, wie er in Figur 4 dargestellt ist, herzustellen, werden zunächst die verschiedenen Teilelemente 1 und 2, wie in Figur 1 gezeigt ist, hergestellt. Jedes Teilelement 1 , 2 wird aus einem mit Kohlenstoff- und Keramik-Fasern verstärkten Verbundwerkstoff aufgebaut. Die Teilelemente 1 und 2, wie sie in Figur 1 zu sehen sind, unterscheiden sich hierbei jeweils durch eine unterschiedliche Faserorientierung, wie durch den Faserverlauf in der oberen, linken Ecke jedes Teilelements 1 , 2 angedeutet ist. Während in den Teilelementen 1 die Fasern im wesentlichen in der Ebene des jeweiligen Teilelements 1 und parallel zu den Seitenkanten des Teilelements ausgerichtet sind, sind die Fasern in den Teilelementen 2, die ebenfalls im wesentlichen in der Ebene des Teileiements liegen, 45° zu der Orientierung der Fasern in den ersten Teilelementen bzw. 45° zu den Seitenkanten des Teilelements 2 ausgerichtet. Wie anhand der Teilelemente 1 angedeutet ist, kann jedes Teileiement aus einzelnen Platten mit geringer Dicke aufgebaut werden.In order to manufacture such a heat exchanger, as shown in FIG. 4, the various sub-elements 1 and 2, as shown in FIG. 1, are first manufactured. Each sub-element 1, 2 is constructed from a composite material reinforced with carbon and ceramic fibers. The sub-elements 1 and 2, as can be seen in FIG. 1, differ in each case by a different fiber orientation, as is indicated by the fiber course in the upper left corner of each sub-element 1, 2. While in the sub-elements 1 the fibers essentially in the plane of the respective sub-element 1 and parallel to the side edges of the sub-element are aligned, the fibers in the sub-elements 2, which are also essentially in the plane of the sub-element, are oriented 45 ° to the orientation of the fibers in the first sub-elements or 45 ° to the side edges of the sub-element 2. As indicated by the sub-elements 1, each sub-element can be constructed from individual plates with a small thickness.
Die Herstellung eines Plattenteils bzw. eines Teilelements 1 , 2 erfolgt aus einem porösen, kohlenstoff-faserverstärkten Kohlenstoffmaterial (C/C) mit sogenannten Langfasern, oder Fasern, die endlos sind, in orthotroper bzw. quasi-isotroper Orientierung zur Plattenebene. Solche Faserplatten werden dann zunächst zu einem Teilelement 1 zusammengefügt, beispielsweise durch Verkleben mit einer kohlenstoff-reichen Paste. Die einzelnen Teilelemente 1 , 2 werden dann ebenfalls miteinander unter Heranziehung dieser Verbindungstechnik verklebt, so daß sich ein Vorkörper ergibt, wie er in Figur 2 dargestellt ist. Danach werden, wie in Figur 3 dargestellt, Bohrungen 6 eingebracht, was mit einem relativ geringen Aufwand möglich ist, da dieser Vorkörper leicht mit herkömmlichen Bohrtechniken bearbeitbar ist. Bei diesem Vorkörper handelt es sich um ein poröses Gebilde, wobei die Poren gegebenenfalls definiert ausgebildet werden können. Hierzu wird vorzugsweise eine Technik angewandt, wobei die einzelnen Kohlenstoff-Fasern in einem kohlenstoff-reichen Polymer eingebettet sind, wobei unter Pyrolyse eine solche definierte Rißstruktur erzeugt und definiert eingestellt werden kann. Die Poren bzw. die Rißstruktur dieser Tragstruktur des C/C- Körpers wird dann mit flüssigem Silicium infiltriert, das unter Wärmeeinwirkung bei Temperaturen im Bereich von 1410°C bis 1700X zu Siiiciumcarbid umgewandelt wird. Die Querschnitte der Bohrungen 6 können definiert eingestellt werden. Gleichzeitig mit dem Infiltrieren von flüssigem Silicium in die Porenstruktur wird im Bereich der Kiebeflächen der flächig miteinander verklebten Teilelemente 1 , 2 eine Silicium- carbid-Verbindungsschicht gebildet, so daß die Klebeschicht durch eine Siiiciumcar- bidschicht ersetzt wird und sich eine homogene, hochfeste Tragstruktur 3 auch im Bereich der Fügestelle einzelner Teilelemente 1 , 2 ergibt.A plate part or a partial element 1, 2 is produced from a porous, carbon-fiber-reinforced carbon material (C / C) with so-called long fibers, or fibers that are endless, in an orthotropic or quasi-isotropic orientation to the plate plane. Such fiberboard are then first assembled into a sub-element 1, for example by gluing with a carbon-rich paste. The individual sub-elements 1, 2 are then also glued to one another using this connection technique, so that a preform results, as shown in FIG. Then, as shown in FIG. 3, bores 6 are made, which is possible with relatively little effort, since this preform can be easily machined using conventional drilling techniques. This pre-body is a porous structure, the pores being able to be formed in a defined manner if necessary. For this purpose, a technique is preferably used, the individual carbon fibers being embedded in a carbon-rich polymer, such a defined crack structure being able to be generated and defined in a pyrolysis manner. The pores or the crack structure of this supporting structure of the C / C body is then infiltrated with liquid silicon, which is converted to silicon carbide under the action of heat at temperatures in the range from 1410 ° C. to 1700 ° C. The cross sections of the bores 6 can be set in a defined manner. Simultaneously with the infiltration of liquid silicon into the pore structure, a silicon carbide connecting layer is formed in the area of the sliding surfaces of the partial elements 1, 2 which are glued together, so that the adhesive layer is replaced by a silicon carbide layer and a homogeneous, high-strength supporting structure 3 also results in the area of the joint of individual sub-elements 1, 2.
Entsprechend den Bohrungsquerschnitten werden die einzusetzenden ersten und zweiten Rohre 4 und 5 dimensioniert, allerdings derart, daß deren Durchmesser geringfügig kleiner ist als der freie Bohrungsdurchmesser, so daß ein Zwischenraum bei eingelegtem Rohr entsteht. Diese Zwischenräume dienen als Dehnungsausgleichsbereich, der mit einer Dehnungsausgleichsschicht 8 aus keramischem Werkstoff und/oder Kohlenstoff gefüllt wird. Die Dehnungsausgleichsschicht 8 kann dadurch gebildet werden, daß, vor Einlegen der Rohre in die Bohrungen, eine Schicht aus Keramik- und/oder Kohlenstoff-Fasern oder -Folien eingefügt wird. Anschließend werden die Rohre eingesteckt, so daß diese unter Einhaltung eines definierten Spalts den verbleibenden Freiraum ausfüllen. Alternativ werden zunächst in die Bohrungen die ersten und zweiten Rohre eingelegt und der Zwischenraum mit einem keramischen Pulvermaterial weitgehendst aufgefüllt. In der Anordnung, wie sie in Figur 4 zu sehen ist, sind die ersten und zweiten Rohre 4, 5 in der Tragstruktur 3 zwar fixiert, allerdings nicht kraft- und formschlüssig so eingebettet, daß sie unverrückbar wären.The first and second tubes 4 and 5 to be used are dimensioned in accordance with the bore cross-sections, but in such a way that their diameter is slightly smaller than the free bore diameter, so that an intermediate space arises when the tube is inserted. These gaps serve as an expansion compensation area, which is filled with an expansion compensation layer 8 made of ceramic material and / or carbon. The expansion compensation layer 8 can be formed by inserting a layer of ceramic and / or carbon fibers or foils before inserting the tubes into the bores. Then the pipes are inserted so that they fill the remaining space while maintaining a defined gap. Alternatively, the first and second tubes are first inserted into the bores and the intermediate space is largely filled with a ceramic powder material. In the arrangement as can be seen in FIG. 4, the first and second tubes 4, 5 are fixed in the support structure 3, but are not embedded in a force-fitting and form-locking manner so that they would be immovable.
Während in Figur 4 ein Wärmetauscher schematisch dargestellt ist, der quer zur Längserstreckung der ersten und zweiten Rohre 4, 5 eine quadratische Struktur aufweist, ist in Figur 5 bzw. in Figur 9 ein Wärmetauscher-Modul gezeigt, das einen hexagonalen Querschnitt mit einer gleichen Seitenlänge aufweist. Prinzipiell ist ein solcher Wärmetauscher so aufgebaut, wie dies vorstehend anhand der Figuren 1 bis 4 erläutert ist, wobei die Figur 7 wiederum ein einzelnes Teilelement 1 , 2 einer solchen Tragstruktur 3 zeigt. Mehrere solcher Teilelemente 1, 2 werden dann aufeinander verklebt, wie in Figur 8 mit den Klebe- bzw. Verbindungsschichten 7 angedeutet ist. Nach Keramisieren dieses Vorkörpers entsprechend der Figur 8 werden dann die Rohre 4, 5 in die Bohrungen eingesteckt, wiederum mit einer keramischen Zwischenschicht, die als Dehnungsschicht 8 dient, wie in Figur 5 angedeutet ist.While a heat exchanger is shown schematically in FIG. 4, which has a square structure transverse to the longitudinal extension of the first and second tubes 4, 5, a heat exchanger module is shown in FIG. 5 and in FIG. 9, which has a hexagonal cross section with the same side length having. In principle, such a heat exchanger is constructed as explained above with reference to FIGS. 1 to 4, FIG. 7 again showing a single partial element 1, 2 of such a support structure 3. Several such sub-elements 1, 2 are then glued to one another, as indicated in FIG. 8 with the adhesive or connecting layers 7. After this pre-body has been ceramized in accordance with FIG. 8, the tubes 4, 5 are then inserted into the bores, again with a ceramic intermediate layer which serves as an expansion layer 8, as indicated in FIG. 5.
Wie zu erkennen ist, können aus dem modulartigen Aufbau des Wärmetauschers mit einzelnen Teilelementen 1 , 2 Wärmetauscher beliebiger Längen hergestellt werden, wozu standardisierte Teile herangezogen werden. Mit einer polygonalen Querschnittsform der Tragstruktur 3, wie sie vorstehend beschrieben ist, insbesondere mit einer hexagonalen Querschnittsform, die Seiten mit gleicher Länge besitzt, können Wärmetauscherstrukturen aufgebaut werden, wie sie beispielsweise in Figur 6 zu sehen ist. Hierbei werden einer zentralen Wärmetauschereinheit weitere Moduleinheiten einer entsprechenden Querschnittsform jeder Seitenfläche zugeordnet, so daß die mittlere, zentrale Wärmetauscher-Moduleinheit vollständig von äußeren Modu- leinheiten umgeben wird. In den Seitenflächen der Moduieinheiten sind, in Längsrichtung der Rohre 4, 5 gesehen, Fixierungsnuten 9 ausgebildet, beispielsweise mit einem halbkreisförmigen Querschnitt, die sich dann beim Aufbau des Wärmetauschers entsprechend der Figur 6 mit den Nuten angrenzender Wärmetauscher-Module zu einer Bohrung ergänzen, in die beispielsweise Fixierstifte oder Fixierstäbe 10 eingesetzt werden können. Die einzelnen Moduleinheiten entsprechend der Figur 6 können mit geeigneten Verbindungstechniken verbunden werden, wozu sich beispielsweise Siliciumcarbidschichten eignen. Die jeweiligen Rohre 4, 5 der Moduleinheiten der Figur 6 können in geeigneter Weise strömungsmäßig miteinander verbunden werden, so daß sich zwei Strömungssysteme ergeben, wobei das erste Strömungssystem die ersten Rohre 4 (heller Querschnitt in Figur 6) umfaßt, während das zweite Rohrsystem (zweite Rohre 5 - dunkel angedeutet in Figur 6) das zweite Rohrsystem bildet. Durch das erste Rohrsystem wird das zu kühlende Fluid geführt, während das zweite Rohrsystem das Kühlfluid aufnimmt.As can be seen, from the modular construction of the heat exchanger with individual sub-elements 1, 2, heat exchangers of any length can be produced, for which standardized parts are used. Has with a polygonal cross-sectional shape of the supporting structure 3, as described above, in particular having a hexagonal cross-sectional shape, the sides of equal length, heat exchange structures can be built, as for example seen in Fig. 6 Here, a central heat exchanger unit further module units are assigned a corresponding cross-sectional shape of each side surface, so that the middle, central heat exchanger module unit is completely surrounded by outer module units. In the side surfaces of the modular units, as seen in the longitudinal direction of the tubes 4, 5, fixing grooves 9 are formed, for example with a semicircular cross section, which then complement one another in the construction of the heat exchanger according to FIG. 6 with the grooves of adjacent heat exchanger modules, in which, for example, fixing pins or fixing rods 10 can be used. The individual module units according to FIG. 6 can be connected using suitable connection techniques, for which purpose silicon carbide layers are suitable. The respective pipes 4, 5 of the module units of FIG. 6 can be connected to one another in a suitable manner in terms of flow, so that two flow systems result, the first flow system comprising the first pipes 4 (light cross section in FIG. 6), while the second pipe system (second Pipes 5 - indicated darkly in Figure 6) forms the second pipe system. The fluid to be cooled is passed through the first pipe system, while the second pipe system receives the cooling fluid.
Wie weiterhin anhand der Figur 6 zu erkennen ist, können mit Moduleinheiten, wie sie in Figur 5 dargestellt sind, andere geometrische Gebilde hergestellt werden, beispielsweise Wärmetauscher, die einen relativ großen, mittleren Hohlraum aufweisen oder komplexe Wärmetauscherstrukturen, wie beispielsweise Wandflächen, die in ihrer Länge und Höhe variabel sind, um sie den Anforderungen jeweils anzupassen.As can also be seen from FIG. 6, other geometric structures can be produced with module units as shown in FIG. 5, for example heat exchangers that have a relatively large, medium cavity or complex heat exchanger structures, such as wall surfaces, in their Length and height are variable in order to adapt them to the requirements.
In Figur 10 ist eine Tragestruktur 3 gezeigt, die aus Faser-Rovings oder Gewebebän- dern gewickelt ist. Wie aus dem angedeuteten Faserverlauf im Bereich der vorderen Stirnflächen der Wickelstruktur zu erkennen ist, ist diese Tragestruktur in Z-Richtung sich aufbauend gewickelt, indem die einzelnen Faserlagen wechselweise um die einzelnen Bohrungen 6, für die zunächst nicht dargestellte Platzhalter während des Wickelvorgangs eingesetzt werden können, gewickelt. Durch den kreuzweisen Verlauf im wesentlichen jeweils um den entsprechenden Platzhalter für das einzusetzende innere Rohr 4 herum ergibt sich eine hochfeste Struktur. Wie weiterhin zu sehen ist, werden die Fasern oder Faserbänder so gelegt, daß sie jeweils zu gegenüberliegenden Platzhaltern verlaufen und dann zu dem jeweils benachbarten Platzhalter geführt werden. Während dieses Wickelvorgangs entstehen an das innere Rohr 4 bzw. die Bohrung 6 für das innere Rohr 4 angrenzend dreieckförmige Hohlräume, in die dann ein entsprechendes Einsatzteil 11 aus einem gut wärmeleitenden Material, beispielsweise einer Faserkeramik, eingesetzt werden kann. Die Dehnungsausgleichsschicht kann bei einem Aufbau, wie er in Figur 10 dargestellt ist, zunächst um Platzhalter-Formkörper herum angeordnet werden, bevor der eigentlichen Wickelvorgang erfolgt. Die Dehnungsausgleichsschicht kann aber auch während des Wickeins durch Aufbringen von Fasern radial um einen entsprechenden Kern oder Bereich die jeweiligen vorgefertigten ersten und zweiten Rohre 4, 5, die allerdings nicht näher in Figur 10 dargestellt sind, aufgebaut werden. FIG. 10 shows a support structure 3 which is wound from fiber rovings or fabric strips. As can be seen from the indicated fiber course in the area of the front end faces of the winding structure, this support structure is wound in a building-up manner in the Z direction, in that the individual fiber layers are alternately around the individual bores 6, for which placeholders (not shown) can be used during the winding process , wrapped. The crosswise course essentially around the corresponding placeholder for the inner tube 4 to be used results in a high-strength structure. As can also be seen, the fibers or fiber tapes are placed in such a way that they each run to opposite placeholders and are then guided to the respectively adjacent placeholder. During this winding process, the inner tube 4 is formed or the bore 6 for the inner tube 4 adjoining triangular cavities, into which a corresponding insert 11 made of a good heat-conducting material, for example a fiber ceramic, can then be inserted. In the case of a construction as shown in FIG. 10, the expansion compensation layer can first be arranged around shaped placeholder bodies before the actual winding process takes place. However, the stretch compensation layer can also be built up during the winding process by applying fibers radially around a corresponding core or area to the respective prefabricated first and second tubes 4, 5, which are not shown in detail in FIG. 10, however.

Claims

P A T E N T A N S P R Ü C H E PATENT CLAIMS
1. Wärmetauscher, der mindestens ein erstes Rohr zum Hindurchleiten eines ersten Fluids und mindestens ein zweites Rohr zum Hindurchleiten eines Wärme abführenden zweiten Fluids aufweist, wobei zumindest das erste Rohr, aus einem fluiddichten, korrosions- und oxidationsbeständigen Werkstoff, in einer aus mehreren einzelnen Teilelementen gebildeten Tragstruktur aus SiC-haltigem Werkstoff in einer Bohrung der Teilelemente gehalten ist, dadurch gekennzeichnet, daß die Tragstruktur (3) aus aufeinandergestapelten und über eine SiC-haltige Verbindungsschicht (7) miteinander verbundenen platten- oder scheibenförmigen Teilelementen (1 , 2) aus einem mit Kohlenstoff- und/oder Keramik-Fasern verstärkten Verbundwerkstoff aufgebaut ist und daß zumindest zwischen dem ersten Rohr (4) und der Tragstruktur (3) eine Dehnungsausgleichsschicht (8) aus keramischem Werkstoff und/oder Kohlenstoff angeordnet ist.1. Heat exchanger, which has at least a first tube for passing a first fluid and at least a second tube for passing a heat-dissipating second fluid, wherein at least the first tube, made of a fluid-tight, corrosion and oxidation resistant material, in one of several individual sub-elements Support structure formed from SiC-containing material is held in a bore of the sub-elements, characterized in that the support structure (3) consists of stacked plate-like or disc-shaped sub-elements (1, 2) connected to one another via an SiC-containing connecting layer (7) composite material reinforced with carbon and / or ceramic fibers and that an expansion compensation layer (8) made of ceramic material and / or carbon is arranged at least between the first tube (4) and the supporting structure (3).
2. Wärmetauscher nach Anspruch 1 , dadurch gekennzeichnet, daß zumindest das erste Rohr (4) aus monolithischer Keramik gebildet ist.2. Heat exchanger according to claim 1, characterized in that at least the first tube (4) is formed from monolithic ceramic.
3. Wärmetauscher nach Anspruch 2, dadurch gekennzeichnet, daß zumindest das erste Rohr (4) aus Siiiciumcarbid, Siliciumnitrid, Cordierit oder Mullit gebildet ist.3. Heat exchanger according to claim 2, characterized in that at least the first tube (4) is made of silicon carbide, silicon nitride, cordierite or mullite.
4. Wärmetauscher nach Anspruch 3, dadurch gekennzeichnet, daß als Siiiciumcarbid ein Siiicium-infiltriertes Siiiciumcarbid (SiSiC) oder gesintertes Siiiciumcarbid (SSiC) verwendet wird. 4. Heat exchanger according to claim 3, characterized in that a Si-silicon-infiltrated silicon carbide (SiSiC) or sintered silicon carbide (SSiC) is used as silicon carbide.
5. Wärmetauscher nach Anspruch 1 , dadurch gekennzeichnet, daß die Dehnungsausgleichsschicht (8) im wesentlichen aus keramischem Pulver oder Kohlenstoffpulver gebildet ist.5. Heat exchanger according to claim 1, characterized in that the expansion compensation layer (8) is essentially made of ceramic powder or carbon powder.
6. Wärmetauscher nach Anspruch 1 , dadurch gekennzeichnet, daß die Dehnungsausgleichsschicht (8) im wesentlichen aus Keramik- und/oder Kohlenstoff-Fasern gebildet ist.6. Heat exchanger according to claim 1, characterized in that the expansion compensation layer (8) is essentially formed from ceramic and / or carbon fibers.
7. Wärmetauscher nach Anspruch 6, dadurch gekennzeichnet, daß die Fasern bevorzugt in Umfangsrichtung der Rohre (4, 5) orientiert sind.7. Heat exchanger according to claim 6, characterized in that the fibers are preferably oriented in the circumferential direction of the tubes (4, 5).
8. Wärmetauscher nach Anspruch 1 , dadurch gekennzeichnet, daß die Dehnungsausgleichsschicht (8) aus einem folienförmigen Werkstoff, insbesondere Graphit-Folie, gebildet ist.8. Heat exchanger according to claim 1, characterized in that the expansion compensation layer (8) is formed from a film-like material, in particular graphite film.
9. Wärmetauscher nach Anspruch 1 , dadurch gekennzeichnet, daß die Dehnungsausgleichsschicht (8) aus einer Mischung aus faser- und puiverförmigem Werkstoff gebildet ist.9. Heat exchanger according to claim 1, characterized in that the expansion compensation layer (8) is formed from a mixture of fibrous and puiver-shaped material.
10. Wärmetauscher nach Anspruch 5, dadurch gekennzeichnet, daß die Dehnungsausgleichsschicht (8) aus Bornitrid- und/oder Aluminiumnitrid-Pulver gebildet ist.10. Heat exchanger according to claim 5, characterized in that the expansion compensation layer (8) is formed from boron nitride and / or aluminum nitride powder.
11. Wärmetauscher nach Anspruch 1 , dadurch gekennzeichnet, daß mindestens 50% der Fasern in den Teilelementen (1 , 2) parallel zur Platten- oder Scheibenebene der als Platten oder Scheiben ausgebildeten Teilelemente (1 , 2) verlaufen.11. Heat exchanger according to claim 1, characterized in that at least 50% of the fibers in the sub-elements (1, 2) run parallel to the plate or disk plane of the sub-elements designed as plates or disks (1, 2).
12. Wärmetauscher nach Anspruch 11 , dadurch gekennzeichnet, daß mindestens 90% der Fasern in den Teiielementen parallel zur Platten- oder Scheibenebene der als Platten oder Scheiben ausgebildeten Teilelemente verlaufen.12. Heat exchanger according to claim 11, characterized in that at least 90% of the fibers in the partial elements run parallel to the plate or disk plane of the partial elements designed as plates or disks.
13. Wärmetauscher nach Anspruch 1 , dadurch gekennzeichnet, daß die Teilelemente (1 , 2) aus einem kohlenstoff-faserverstärkten Verbundwerkstoff gebildet sind, wobei die Kohlenstoff-Fasern in Siiiciumcarbid eingebettet sind, das durch Infiltrieren von flüssigem Silicium und unter Wärmeeinwirkung mit Kohlenstoff zu Siiiciumcarbid umgewandelt ist.13. Heat exchanger according to claim 1, characterized in that the sub-elements (1, 2) are formed from a carbon-fiber reinforced composite material, the carbon fibers being embedded in silicon carbide through Infiltration of liquid silicon and under the action of heat with carbon is converted to Siiiciumcarbid.
14. Wärmetauscher nach Anspruch 1 , dadurch gekennzeichnet, daß die Faserverstärkung in den Teilelementen (1, 2) aus zweidimensionaien Geweben, Faser- Rovings oder Gewebe-Bändern gebildet ist.14. Heat exchanger according to claim 1, characterized in that the fiber reinforcement in the sub-elements (1, 2) is formed from two-dimensional fabrics, fiber rovings or fabric tapes.
"15. Wärmetauscher nach Anspruch 14, dadurch gekennzeichnet, daß die Faserverstärkung der Teilelemente (1, 2) aus gewickelten Faser-Rovings oder Gewebe-Bändern oder gestrickten Faser-Rovings gebildet ist (Figur 10). " 15. Heat exchanger according to claim 14, characterized in that the fiber reinforcement of the sub-elements (1, 2) is formed from wound fiber rovings or fabric strips or knitted fiber rovings (Figure 10).
16. Wärmetauscher nach Anspruch 15, dadurch gekennzeichnet, daß in durch die Faserwicklung erzeugte Zwischenhohlräume diese ausfüllende Einsatzteile mit hoher, gerichteter Wärmeleitung eingesetzt oder in diesen gebildet sind.16. Heat exchanger according to claim 15, characterized in that these filling insert parts are inserted with high, directed heat conduction in or formed in the intermediate cavities generated by the fiber winding.
17. Wärmetauscher nach Anspruch 16, dadurch gekennzeichnet, daß die Einsatzteile aus keramischem oder keramisiertem, kohienstoff-faserverstärktem Verbundwerkstoff gebildet sind.17. Heat exchanger according to claim 16, characterized in that the insert parts are made of ceramic or ceramized, carbon fiber-reinforced composite material.
18. Wärmetauscher nach Anspruch 17, dadurch gekennzeichnet, daß die Einsatzteile aus SiC gebildet sind.18. Heat exchanger according to claim 17, characterized in that the insert parts are formed from SiC.
19. Wärmetauscher nach Anspruch 1 , dadurch gekennzeichnet, daß dem mindestens einen ersten Rohr (4) das mindestens eine zweite Rohr (5) benachbart in einer in den Teilelementen (1, 2) eingebrachten Bohrung (6) gehalten ist.19. Heat exchanger according to claim 1, characterized in that the at least one first tube (4), the at least one second tube (5) is held adjacent in a bore (6) made in the sub-elements (1, 2).
20. Wärmetauscher nach Anspruch 19, dadurch gekennzeichnet, daß um ein zentrales, erstes Rohr (4) mehrere zweite Rohre (5) angeordnet sind.20. Heat exchanger according to claim 19, characterized in that a plurality of second tubes (5) are arranged around a central, first tube (4).
21. Wärmetauscher nach Anspruch 20, dadurch gekennzeichnet, daß die zweiten Rohre symmetrisch um das zentrale erste Rohr angeordnet sind.21. Heat exchanger according to claim 20, characterized in that the second tubes are arranged symmetrically around the central first tube.
22. Wärmetauscher nach Anspruch 20 oder 21 , dadurch gekennzeichnet, daß die Achsen der ersten und der zweiten Rohre (4, 5) parallel zueinander verlaufen.22. Heat exchanger according to claim 20 or 21, characterized in that the axes of the first and the second tubes (4, 5) run parallel to one another.
23. Wärmetauscher nach einem der Ansprüche 1 bis 22, dadurch gekennzeichnet, daß als Wärmetauscher-Moduleinheit mehrere Moduleinheiten zu einer Wärmetauschereinheit zusammengeführt sind, wobei die Querschnittsform der Moduleinheit so ausgeführt ist, daß aneinandergrenzende Moduleinheiten flächig aneinander liegen.23. Heat exchanger according to one of claims 1 to 22, characterized in that as a heat exchanger module unit a plurality of module units Heat exchanger unit are brought together, wherein the cross-sectional shape of the module unit is designed so that adjacent module units lie flat against each other.
24. Wärmetauscher nach Anspruch 23, dadurch gekennzeichnet, daß die Querschnittsform der Moduieinheiten als Polygon, vorzugsweise als Hexagon, ausgeführt ist.24. Heat exchanger according to claim 23, characterized in that the cross-sectional shape of the modular units is designed as a polygon, preferably as a hexagon.
25. Wärmetauscher nach Anspruch 24, dadurch gekennzeichnet, daß das Polygon gleiche Seitenlängen aufweist.25. Heat exchanger according to claim 24, characterized in that the polygon has the same side lengths.
26. Wärmetauscher nach Anspruch 25 dadurch gekennzeichnet, daß an jeder Seite einer zentralen Moduleinheit eine weitere Moduleinheit anliegt.26. Heat exchanger according to claim 25, characterized in that a further module unit is present on each side of a central module unit.
27. Wärmetauscher nach Anspruch 1 oder Anspruch 23, dadurch gekennzeichnet, daß in dessen Außenoberfläche Fixiernuten (9) vorgesehen sind.27. Heat exchanger according to claim 1 or claim 23, characterized in that fixing grooves (9) are provided in the outer surface thereof.
28. Wärmetauscher nach Anspruch 1 oder Anspruch 23, dadurch gekennzeichnet, daß die Außenoberfläche der Tragstruktur (3) mit einer Schutzschicht gegen Oxidation oder Korrosion versehen ist.28. Heat exchanger according to claim 1 or claim 23, characterized in that the outer surface of the support structure (3) is provided with a protective layer against oxidation or corrosion.
29. Wärmetauscher nach Anspruch 28, dadurch gekennzeichnet, daß die Schutzschicht aus Siiiciumcarbid und/oder Siliciumdioxid und/oder Molybdändisilicid gebildet ist.29. Heat exchanger according to claim 28, characterized in that the protective layer is made of silicon carbide and / or silicon dioxide and / or molybdenum disilicide.
30. Wärmetauscher nach Anspruch 1 , dadurch gekennzeichnet, daß in der Tragstruktur (3) mehrere Teilelemente (1 , 2) jeweils zu Gruppen zusammengefaßt sind und benachbarte Gruppen eine unterschiedliche Faserorientierung aufweisen. 30. Heat exchanger according to claim 1, characterized in that in the support structure (3) a plurality of sub-elements (1, 2) are each combined into groups and adjacent groups have a different fiber orientation.
EP98921490A 1997-07-16 1998-04-25 Heat exchanger Expired - Lifetime EP0996848B1 (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
DE19730389 1997-07-16
DE19730389A DE19730389C2 (en) 1997-07-16 1997-07-16 heat exchangers
PCT/EP1998/002472 WO1999004213A1 (en) 1997-07-16 1998-04-25 Heat exchanger

Publications (2)

Publication Number Publication Date
EP0996848A1 true EP0996848A1 (en) 2000-05-03
EP0996848B1 EP0996848B1 (en) 2001-08-01

Family

ID=7835824

Family Applications (1)

Application Number Title Priority Date Filing Date
EP98921490A Expired - Lifetime EP0996848B1 (en) 1997-07-16 1998-04-25 Heat exchanger

Country Status (3)

Country Link
EP (1) EP0996848B1 (en)
DE (2) DE19730389C2 (en)
WO (1) WO1999004213A1 (en)

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Also Published As

Publication number Publication date
DE59801133D1 (en) 2001-09-06
DE19730389A1 (en) 1999-01-21
WO1999004213A1 (en) 1999-01-28
EP0996848B1 (en) 2001-08-01
DE19730389C2 (en) 2002-06-06

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