EP0159232A1 - Steam generator, particularly for a pressurized-water nuclear reactor - Google Patents

Steam generator, particularly for a pressurized-water nuclear reactor Download PDF

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Publication number
EP0159232A1
EP0159232A1 EP85400504A EP85400504A EP0159232A1 EP 0159232 A1 EP0159232 A1 EP 0159232A1 EP 85400504 A EP85400504 A EP 85400504A EP 85400504 A EP85400504 A EP 85400504A EP 0159232 A1 EP0159232 A1 EP 0159232A1
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EP
European Patent Office
Prior art keywords
tube plate
water box
water
conical
steam generator
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
EP85400504A
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German (de)
French (fr)
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EP0159232B1 (en
Inventor
Jean-Paul Badoux
Jean Edmond Chaix
Michel Metteey
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Commissariat a lEnergie Atomique et aux Energies Alternatives CEA
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Commissariat a lEnergie Atomique CEA
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Publication of EP0159232A1 publication Critical patent/EP0159232A1/en
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Publication of EP0159232B1 publication Critical patent/EP0159232B1/en
Expired legal-status Critical Current

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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F22—STEAM GENERATION
    • F22B—METHODS OF STEAM GENERATION; STEAM BOILERS
    • F22B37/00—Component parts or details of steam boilers
    • F22B37/02—Component parts or details of steam boilers applicable to more than one kind or type of steam boiler
    • F22B37/22—Drums; Headers; Accessories therefor
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F22—STEAM GENERATION
    • F22B—METHODS OF STEAM GENERATION; STEAM BOILERS
    • F22B1/00—Methods of steam generation characterised by form of heating method
    • F22B1/02—Methods of steam generation characterised by form of heating method by exploitation of the heat content of hot heat carriers
    • F22B1/023—Methods of steam generation characterised by form of heating method by exploitation of the heat content of hot heat carriers with heating tubes, for nuclear reactors as far as they are not classified, according to a specified heating fluid, in another group
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F28—HEAT EXCHANGE IN GENERAL
    • F28F—DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
    • F28F9/00—Casings; Header boxes; Auxiliary supports for elements; Auxiliary members within casings
    • F28F9/02—Header boxes; End plates
    • F28F9/0219—Arrangements for sealing end plates into casing or header box; Header box sub-elements
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F28—HEAT EXCHANGE IN GENERAL
    • F28F—DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
    • F28F2275/00—Fastening; Joining
    • F28F2275/20—Fastening; Joining with threaded elements

Definitions

  • the subject of the invention is a steam generator, in particular for a pressurized water nuclear reactor.
  • the enclosure 1 of the reactor is shown in which the core 2 is located and where on the one hand circulates in 3 the ascending hot water leaving the core in the direction of the arrows F and on the other hand, l cold water going down between the casing 1 and the basket 4 of the reactor.
  • the steam generator 5 comprises, in known manner, a water box 6, in which the water from the reactor 1 circulates, and, above this water box 6, a ferrule 7 traversed by the secondary water which enters at 8 and leaves at 9 from this secondary ferrule 7.
  • a conduit 10 connects the reactor 1 with the water box 6 and in fact comprises two concentric annular passages, namely a central passage 11 through which the hot water enters the water box 6 and a peripheral passage 12 through which comes out the cold water coming from this same water box 6 and returning to the reactor 1 between the basket 4 and the enclosure 1 to be reinjected at the base of the heart.
  • the water box 6 is separated from the secondary shell 7 by a tube plate 13 in which are vertically located a number of heat exchanger tubes 14 in the form of an inverted U and traversed by the primary fluid; this water box 6 is divided into two parts, namely a hot compartment 15 and a cold compartment 16.
  • the secondary water which ascends upwardly inside the secondary shell 7, gradually heats up and vaporizes while rising along the preceding U-shaped tubes 14 ( Figures 1 and 2).
  • the present invention specifically relates to a steam generator for a pressurized water nuclear reactor which makes it possible, using simple means to be implemented, to make a connection between the secondary shell and the tube plate without accumulation of lateral constraints and which also makes the steam generator internally removable.
  • the handling lugs located at the periphery of the tube plate comprise housings whose conical profile makes it possible to receive see the conical collars which equip the studs, thus allowing during a disassembly operation of the single water box, the handling of the secondary plate-tube-ferrule assembly without breaking their seal.
  • the secondary shell, the tube plate and the water box are therefore independent of each other and completely removable assemblies. Furthermore, the closure of the water box and that of the secondary enclosure of the steam generator are carried out globally and by means also independent. In the generator that is the subject of the invention, this thus achieves the total removal of the stresses in the angular zone of connection of the tube plate with the secondary ferrule, which makes it possible to increase the number of exchange tubes of heat contained in this shell and, moreover, the complete disassembly of the steam generator makes its use much easier than that of welded generators of the prior art.
  • FIG. 3 there is shown the secondary ferrule 7, the tube plate 13 and the water box 6.
  • the secondary ferrule 7 ends according to the invention at its lower part by an annular peduncle 20 having a double conical bearing 21 and 22 at its lower part for connection with the tube plate 13.
  • the latter comprises for this purpose a corresponding female groove 23 also comprising two conical bearing surfaces intended to cooperate with the conical bearing surfaces 21 and 22 of the peduncle 20.
  • Two seals metal toric sealing 24 ensure the sealing between the tube plate 13 and the secondary shell 7 when the assembly, as will be seen below, is tightened by the tie rod 25 and the clamping ring 26.
  • the upper part of the peduncle 20 also has a conical bearing 27 cooperating with a corresponding bearing of this clamping ring 26.
  • the water box 6 is provided with a plane connection bearing t 28 with two metal O-rings interposed 29 between the water box 6 and the tube plate 13.
  • Tightening in the vertical direction of the three preceding independent elements is carried out using tie rods 25, nuts 30 and studs 31 installed, in accordance with the invention, in the water box 6.
  • a certain number of handling lugs such as 32 which include housings 33 with conical bearing 34 for the studs 31, which comprise at for this purpose, a conical collar 35 intended to come into abutment against the corresponding conical part 34.
  • This allows, when it is desired for any reason, for example a maintenance operation, dismantle the water box 6 without breaking the seal of the tube plate 13 and of the secondary shell 7, of handling this tube plate 13, using tie rods 25 passing through the ears 32, maintaining tight contact with the secondary ferrule 7.
  • the sequence of operations is in this case as follows.
  • the handling lugs 32 are three in number on the periphery and each comprise two housings 33a and 33b for the studs 31. These housings 33a and 33b make it possible to protect the threads of the studs 31 during handling operations. The number of these studs used for resuming tightening is determined so that we can ward off the possibility of one of them seizing up during maneuver.

Abstract

Générateur de vapeur, notamment pour réacteur nucléaire à eau pressurisée, comportant de façon connue une boîte à eau (6) où circule l'eau chaude sortant du coeur du réacteur pour pénétrer ensuite dans une série de tubes échangeurs de chaleur (14), implantés dans une plaque à tubes (13) et s'étendant à l'intérieur d'une virole secondaire (7), parcourue par l'eau secondaire, caractérisé en ce que la boîte à eau, la virole secondaire et la plaque à tubes sont trois ensembles indépendants, et démontables.Steam generator, in particular for a pressurized water nuclear reactor, comprising, in a known manner, a water box (6) through which the hot water leaving the reactor core circulates and then enters a series of heat exchanger tubes (14), located in a tube plate (13) and extending inside a secondary ferrule (7), traversed by the secondary water, characterized in that the water box, the secondary ferrule and the tube plate are three independent and removable assemblies.

Description

L'invention a pour objet un générateur de vapeur, notamment pour réacteur nucléaire à eau pressurisée.The subject of the invention is a steam generator, in particular for a pressurized water nuclear reactor.

On connaît dans l'industrie nucléaire les générateurs de vapeur utilisés en liaison avec des réacteurs à eau sous pression et dont un exemple schématique d'un type en soi connu est décrit en référence à la figure 1.Steam generators used in connection with pressurized water reactors are known in the nuclear industry and a schematic example of a type known per se is described with reference to FIG. 1.

Sur cette figure 1, on a représenté l'enceinte 1 du réacteur dans lequel se trouve le coeur 2 et où circule d'une part en 3 l'eau chaude ascendante sortant du coeur en direction des flèches F et d'autre part, l'eau froide descendante circulant entre l'enveloppe 1 et le panier 4 du réacteur.In this FIG. 1, the enclosure 1 of the reactor is shown in which the core 2 is located and where on the one hand circulates in 3 the ascending hot water leaving the core in the direction of the arrows F and on the other hand, l cold water going down between the casing 1 and the basket 4 of the reactor.

Le générateur de vapeur 5 comporte, de façon connue, une boite à eau 6, dans laquelle circule l'eau en provenance du réacteur 1, et, au-dessus de cette boîte à eau 6, une virole 7 parcourue par l'eau secondaire qui entre en 8 et sort en 9 de cette virole secondaire 7. Un conduit 10 relie le réacteur 1 avec la boîte à eau 6 et comporte en fait deux passages annulaires concentriques à savoir un passage central 11 par lequel pénètre l'eau chaude dans la boîte à eau 6 et un passage périphérique 12 par lequel ressort l'eau froide provenant de cette même boîte à eau 6 et retournant dans le réacteur 1 entre le panier 4 et l'enceinte 1 pour être réinjectée à la base du coeur.The steam generator 5 comprises, in known manner, a water box 6, in which the water from the reactor 1 circulates, and, above this water box 6, a ferrule 7 traversed by the secondary water which enters at 8 and leaves at 9 from this secondary ferrule 7. A conduit 10 connects the reactor 1 with the water box 6 and in fact comprises two concentric annular passages, namely a central passage 11 through which the hot water enters the water box 6 and a peripheral passage 12 through which comes out the cold water coming from this same water box 6 and returning to the reactor 1 between the basket 4 and the enclosure 1 to be reinjected at the base of the heart.

De façon également connue, la boîte à eau 6 est séparée de la virole secondaire 7 par une plaque à tubes 13 dans laquelle sont implantés verticalement un certain nombre de tubes échangeurs de chaleur 14 en forme de U renversé et parcourus par le fluide primaire ; cette boîte à eau 6 est divisée en deux parties, à savoir un compartiment chaud 15 et un compartiment froid 16. L'eau secondaire, qui parcourt de façon ascendante l'intérieur de la virole secondaire 7, s'échauffe et se vaporise progressivement en montant le long des tubes en U 14 précédents (Figures 1 et 2).In a manner also known, the water box 6 is separated from the secondary shell 7 by a tube plate 13 in which are vertically located a number of heat exchanger tubes 14 in the form of an inverted U and traversed by the primary fluid; this water box 6 is divided into two parts, namely a hot compartment 15 and a cold compartment 16. The secondary water, which ascends upwardly inside the secondary shell 7, gradually heats up and vaporizes while rising along the preceding U-shaped tubes 14 (Figures 1 and 2).

Dans toutes les réalisations actuelles de générateurs de vapeur de réacteurs à boucles telles que décrites précédemment, ou de réacteurs intégrés du type CAP pour lesquels la cuve primaire fait office de boite à eau, la virole secondaire 7 est soudée directement à la plaque à tubes 13 laquelle est fixée par serrage sur la boîte à eau 6. Par suite de la différence de pression importante (de l'ordre de 100 bars) à laquelle est soumise la plaque à tube 13, des contraintes s'accumulent dans la zone angulaire de raccordement de cette plaque 13 avec la virole secondaire 7. Pour ne pas trop fragiliser cette zone, il n'est donc pas possible de percer la plaque trop près de sa jonction avec la virole secondaire 7 pour y implanter des tubes, ce qui augmente l'encombrement du générateur de vapeur comme permet de le comprendre la figure 2 où l'on voit qu'un espace minimal est nécessaire entre la paroi latérale 7 de la virole secondaire et le premier tube 14 implanté dans la plaque à tubes 13.In all current embodiments of steam generators of loop reactors as described above, or of integrated reactors of the CAP type for which the primary tank acts as a water box, the secondary ferrule 7 is welded directly to the tube plate 13 which is fixed by clamping on the water box 6. As a result of the significant pressure difference (of the order of 100 bars) to which the tube plate 13 is subjected, stresses accumulate in the angular connection zone of this plate 13 with the secondary ferrule 7. In order not to weaken this zone too much, it is therefore not possible to pierce the plate too close to its junction with the secondary ferrule 7 to implant tubes therein, which increases the space requirement of the steam generator as can be understood from FIG. 2 where it can be seen that a minimum space is required between the side wall 7 of the secondary shell and the first tube 14 implanted in the tube plate 13.

Par ailleurs, la partie secondaire d'un tel générateur de vapeur n'est pas démontable et il est par conséquent très difficile de le réparer ou même plus simplement de le nettoyer lorsque cela est rendu nécessaire après un certain temps de fonctionnement et son inspection en service est toujours une opération compliquée et dangereuse.Furthermore, the secondary part of such a steam generator is not removable and it is therefore very difficult to repair it or even more simply to clean it when it becomes necessary after a certain period of operation and its inspection in service is always a complicated and dangerous operation.

La présente invention a précisément pour objet un générateur de vapeur pour réacteur nucléaire à eau pressurisée qui permet, à l'aide de moyens simples à mettre en oeuvre, de réaliser une liaison entre la virole secondaire et la plaque à tubes sans accumulation de contraintes latérales et qui de plus, rend le générateur de vapeur internement démontable.The present invention specifically relates to a steam generator for a pressurized water nuclear reactor which makes it possible, using simple means to be implemented, to make a connection between the secondary shell and the tube plate without accumulation of lateral constraints and which also makes the steam generator internally removable.

Ce générateur de vapeur comportant de façon connue une boîte à eau où circule l'eau chaude sortant du coeur du réacteur pour pénétrer ensuite dans une série de tubes échangeurs de chaleur, implantés dans une plaque à tubes et s'étendant à l'intérieur d'une virole secondaire, parcourue par l'eau secondaire, la boîte à eau, la virole secondaire et la plaque à tubes étant trois ensembles indépendants et démontables, caractérisé en ce que :

  • - la virole secondaire se termine à sa partie inférieure, par un pédoncule annulaire comportant d'une part une double portée conique coopérant par deux joints toriques avec une rainure femelle à deux portées coniques creusée dans la surface supérieure de la plaque à tubes et d'autre part, à sa périphérie externe, une portée conique associée à un anneau de serrage ;
  • - la boîte à eau se termine, à sa partie supérieure, par une bride munie d'une portée plane de raccordement, avec deux joints toriques interposés, à la surface inférieure de la plaque à tubes ;
  • - un système de tirants, dont certains traversant des oreilles de manutention en périphérie de la plaque à tubes, de goujons implantés dans la bride de la boîte à eau et d'écrous, assure, par l'intermédiaire de l'anneau de serrage, l'assemblage et le serrage étanche des trois ensembles indépendants précédents.
This steam generator comprising, in a known manner, a water box through which the hot water leaving the reactor core circulates, then entering a series of heat exchanger tubes, located in a tube plate and extending inside d '' a secondary ferrule, traversed by the secondary water, the water box, the secondary ferrule and the tube plate being three independent and removable assemblies, characterized in that:
  • - the secondary ferrule ends at its lower part, by an annular peduncle comprising on the one hand a double conical bearing cooperating by two O-rings with a female groove with two conical bearing surfaces hollowed out in the upper surface of the tube plate and on the other hand, at its outer periphery, a conical bearing associated with a clamping ring;
  • - the water box ends, at its upper part, with a flange provided with a flat connection surface, with two O-rings interposed, on the lower surface of the tube plate;
  • - a system of tie rods, some of which pass through handling lugs on the periphery of the tube plate, of studs installed in the flange of the water box and of nuts, ensures, by means of the tightening ring, the assembly and tight tightening of the three preceding independent assemblies.

Selon une caractéristique importante de la présente invention, les oreilles de manutention implantées en périphérie de la plaque à tubes comportent des logements dont le profil conique permet de recevoir les collets coniques qui équipent les goujons, permettant ainsi lors d'une manoeuvre de démontage de la seule boîte à eau, la manutention de l'ensemble plaque à tubes-virole secondaire sans rompre leur étanchéité.According to an important characteristic of the present invention, the handling lugs located at the periphery of the tube plate comprise housings whose conical profile makes it possible to receive see the conical collars which equip the studs, thus allowing during a disassembly operation of the single water box, the handling of the secondary plate-tube-ferrule assembly without breaking their seal.

Dans le générateur de vapeur, objet de l'invention, la virole secondaire, la plaque à tubes et la boite à eau sont donc des ensembles indépendants les uns des autres et parfaitement démontables. Par ailleurs, la fermeture de la boite à eau et celle de l'enceinte secondaire du générateur de vapeur sont réalisées de façon globale et par des moyens également indépendants. On parvient donc ainsi, dans le générateur objet de l'invention, à la suppression totale des contraintes dans la zone angulaire de raccordement de la plaque à tubes avec la virole secondaire, ce qui permet d'augmenter le nombre de tubes d'échange de chaleur contenus dans cette virole et, par ailleurs, la démontabilité intégrale du générateur de vapeur rend son utilisation beaucoup plus facile que celle des générateurs soudés de l'art antérieur.In the steam generator, object of the invention, the secondary shell, the tube plate and the water box are therefore independent of each other and completely removable assemblies. Furthermore, the closure of the water box and that of the secondary enclosure of the steam generator are carried out globally and by means also independent. In the generator that is the subject of the invention, this thus achieves the total removal of the stresses in the angular zone of connection of the tube plate with the secondary ferrule, which makes it possible to increase the number of exchange tubes of heat contained in this shell and, moreover, the complete disassembly of the steam generator makes its use much easier than that of welded generators of the prior art.

De toute façon, l'invention sera mieux comprise en se référant à la description qui suit d'un exemple de réalisation, donné à titre illustratif et non limitatif, d'un tel générateur de vapeur. Cette description sera faite en se référant aux figures 3 et 4 ci-jointes, sur lesquelles :

  • - la figure 3 est une vue en coupe élévation qui montre en détail le maintien en contact étanche sur la plaque à tubes d'une part de la virole secondaire et d'autre part de la boîte à eau ;
  • - la figure 4 est une vue de dessus en coupe horizontale selon le plan XX de la figure 3 qui montre la disposition périphérique de la plaque à tubes et la position des différents tirants de maintien de la structure.
In any case, the invention will be better understood by referring to the following description of an exemplary embodiment, given by way of illustration and not limitation, of such a steam generator. This description will be made with reference to Figures 3 and 4 attached, in which:
  • - Figure 3 is an elevational sectional view which shows in detail the maintenance in sealed contact on the tube plate on the one hand of the secondary shell and on the other hand of the water box;
  • - Figure 4 is a top view in horizontal section along the plane XX of Figure 3 which shows the peripheral arrangement of the tube plate and the position of the various tie rods for holding the structure.

Sur la figure 3, on voit représentée la virole secondaire 7, la plaque à tubes 13 et la boite à eau 6. La virole secondaire 7 se termine conformément à l'invention à sa partie inférieure par un pédoncule annulaire 20 comportant une double portée conique 21 et 22 à sa partie inférieure de liaison avec la plaque à tubes 13. Cette dernière comporte à cet effet une rainure femelle 23 correspondante comportant également deux portées coniques destinées à coopérer avec les portées coniques 21 et 22 du pédoncule 20. Deux joints d'étanchéité toriques métalliques 24 assurent l'étanchéité entre la plaque à tubes 13 et la virole secondaire 7 lorsque l'ensemble, comme on le verra plus loin, est serré par le tirant 25 et l'anneau de serrage 26. A cet effet, la partie supérieure du pédoncule 20 comporte également une portée conique 27 coopérant avec une portée correspondante de cet anneau de serrage 26. A la partie inférieure du dispositif, la boîte à eau 6 est munie d'une portée plane de raccordement 28 avec deux joints toriques métalliques interposés 29 entre la boîte à eau 6 et la plaque à tube 13.In Figure 3, there is shown the secondary ferrule 7, the tube plate 13 and the water box 6. The secondary ferrule 7 ends according to the invention at its lower part by an annular peduncle 20 having a double conical bearing 21 and 22 at its lower part for connection with the tube plate 13. The latter comprises for this purpose a corresponding female groove 23 also comprising two conical bearing surfaces intended to cooperate with the conical bearing surfaces 21 and 22 of the peduncle 20. Two seals metal toric sealing 24 ensure the sealing between the tube plate 13 and the secondary shell 7 when the assembly, as will be seen below, is tightened by the tie rod 25 and the clamping ring 26. For this purpose, the upper part of the peduncle 20 also has a conical bearing 27 cooperating with a corresponding bearing of this clamping ring 26. At the lower part of the device, the water box 6 is provided with a plane connection bearing t 28 with two metal O-rings interposed 29 between the water box 6 and the tube plate 13.

Le serrage dans le sens vertical des trois éléments indépendants précédents est réalisé à l'aide des tirants 25, des écrous 30 et des goujons 31 implantés, conformément à l'invention, dans la boîte à eau 6.Tightening in the vertical direction of the three preceding independent elements is carried out using tie rods 25, nuts 30 and studs 31 installed, in accordance with the invention, in the water box 6.

Sur la périphérie de la plaque à tubes 13.se trouvent, comme on le voit sur la figure 4, un certain nombre d'oreilles de manutention telles que 32 qui comportent des logements 33 à portée conique 34 pour les goujons 31, lesquels comportent à cet effet, un collet conique 35 destiné à venir en butée contre la partie conique correspondante 34. Ceci permet, lorsque l'on désire pour une raison quelconque, par exemple une manoeuvre d'entretien, démonter la boite à eau 6 sans rompre l'étanchéité de la plaque à tubes 13 et de la virole secondaire 7, de manutentionner cette plaque à tubes 13, à l'aide des tirants 25 traversant les oreilles 32, en maintenant un contact étanche avec la virole secondaire 7. La séquence des manoeuvres est dans ce cas la suivante. On commence par desserrer les écrous 30 quatre par quatre en plusieurs passes à l'aide de vérins extenseurs, sans les desserrer en deça du couple minimal imposé par le maintien de l'étanchéité secondaire. A la dernière passe, les goujons 31 correspondant aux-oreilles 32 sont desserrés complètement puis dévissés et remontés dans les logements 33 correspondants de façon à ce que le collet conique 35 de chacun d'entre eux vienne au contact de la portée conique 34 du fond de logement des oreilles de manutention 32. Les goujons 31, correspondant aux oreilles 32, sont ensuite resserrés de façon à solidariser à nouveau la plaque à tubes 13 et la virole secondaire 7 sans permettre le desserrage des joints toriques 24. Les autres goujons 31 sont alors desserrés complètement.On the periphery of the tube plate 13. are, as can be seen in FIG. 4, a certain number of handling lugs such as 32 which include housings 33 with conical bearing 34 for the studs 31, which comprise at for this purpose, a conical collar 35 intended to come into abutment against the corresponding conical part 34. This allows, when it is desired for any reason, for example a maintenance operation, dismantle the water box 6 without breaking the seal of the tube plate 13 and of the secondary shell 7, of handling this tube plate 13, using tie rods 25 passing through the ears 32, maintaining tight contact with the secondary ferrule 7. The sequence of operations is in this case as follows. We start by loosening the nuts 30 four by four in several passes using expansion cylinders, without loosening them below the minimum torque imposed by maintaining the secondary seal. At the last pass, the studs 31 corresponding to the ears 32 are loosened completely then unscrewed and reassembled in the corresponding housings 33 so that the conical collar 35 of each of them comes into contact with the conical seat 34 of the bottom for accommodating the handling ears 32. The studs 31, corresponding to the ears 32, are then tightened so as to re-join the tube plate 13 and the secondary ferrule 7 without allowing the O-rings to be loosened 24. The other studs 31 are then loosen completely.

Dans un mode de réalisation préféré de l'invention, les oreilles de manutention 32 sont au nombre de trois sur la périphérie et comportent chacune deux logements 33a et 33b pour les goujons 31. Ces logements 33a et 33b permettent de protéger les filetages des goujons 31 lors des opérations de manutention. Le nombre de ces goujons servant à la reprise du serrage est déterminé de façon à ce que l'on puisse parer l'éventualité du grippage de l'un d'entre eux en cours de manoeuvre.In a preferred embodiment of the invention, the handling lugs 32 are three in number on the periphery and each comprise two housings 33a and 33b for the studs 31. These housings 33a and 33b make it possible to protect the threads of the studs 31 during handling operations. The number of these studs used for resuming tightening is determined so that we can ward off the possibility of one of them seizing up during maneuver.

Sur la figure 4, on voit les tirants 36, 37, 38, 39, 40 et 41 qui tous, par l'intermédiaire des écrous 30 et des goujons 31 correspondants assurent le serrage de la virole secondaire 7 et de la boite à eau 6 sur la plaque à tubes 13 et dont deux d'entre eux, les tirants 39 et 40 servent en outre à la manutention sous serrage de l'ensemble plaque à tubes 13, virole secondaire 7 lors d'une opération de démontage de la boîte à eau 6.In Figure 4, we see the tie rods 36, 37, 38, 39, 40 and 41 which all, through the nuts 30 and studs 31 corresponding ensure the tightening of the secondary ferrule 7 and of the water box 6 on the tube plate 13 and two of which, the tie rods 39 and 40 are also used for tightening handling of the tube plate assembly 13, ferrule secondary 7 during a disassembly operation of the water box 6.

Le générateur de vapeur objet de l'invention qui vient d'être décrit précédemment, présente un certain nombre d'avantages dont les principaux sont évidemment l'accès possible au faisceau de tubes secondaires 14 et aux structures internes du générateur lui-même ; mais il possède en même temps un certain nombre d'avantages complémentaires non négligeables parmi lesquels on peut citer :

  • - du point de vue de l'aménagement du faisceau la suppression de la zone de raccordement dans le bas de la virole, qui permet de gagner de la place disponible pour l'implantation des tubes du faisceau ;
  • - le fait que le pédoncule de la virole secondaire travaille en compression, et donc de façon plus favorable qu'une bride classique ;
  • - le système qui permet de précontraindre la plaque à tubes en lui donnant une flèche vers le bas au moment du serrage ;
  • - la double portée conique qui assure des contacts surfaciques permettant de conserver des niveaux de pression de contact faibles ainsi que des conditions de glissement très satisfaisantes (le glissement est bloqué dès le rattrapage des jeux par la portée conique externe),
  • - le système à double pente qui permet d'abaisser le niveau des contraintes et donc, de diminuer l'épaisseur de la plaque à tubes, toutes choses égales par ailleurs ;
  • - au niveau de la fabrication, le fait de séparer complètement les problèmes de réalisation de l'ensemble plaque+faisceau, de ceux de l'ensemble virole secondaire.
The steam generator object of the invention which has just been described above, has a number of advantages, the main of which are obviously possible access to the bundle of secondary tubes 14 and to the internal structures of the generator itself; but at the same time it has a number of non-negligible additional advantages, among which we can cite:
  • - from the point of view of the layout of the beam, the elimination of the connection zone at the bottom of the shell, which saves the space available for installing the beam tubes;
  • - the fact that the peduncle of the secondary ferrule works in compression, and therefore more favorably than a conventional flange;
  • - the system which makes it possible to prestress the tube plate by giving it a downward arrow when tightening;
  • - the double conical bearing which provides surface contacts making it possible to maintain low contact pressure levels as well as very satisfactory sliding conditions (the sliding is blocked as soon as the clearances are taken up by the external conical bearing),
  • - the double slope system which makes it possible to lower the level of stresses and therefore, to reduce the thickness of the tube plate, all other things being equal;
  • - at the manufacturing level, the fact of completely separating the problems of realization of the plate + beam assembly, of those of the secondary ferrule assembly.

Claims (2)

1. Générateur de vapeur, notamment pour réacteurs nucléaires à eau pressurisée, comportant de façon connue une boite à eau (6) où circule l'eau chaude sortant du coeur du réacteur pour pénétrer ensuite dans une série de tubes échangeurs de chaleur (14), implantés dans une plaque à tubes (13) et s'étendant à l'intérieur d'une virole secondaire (7), parcourue par l'eau secondaire, la boîte à eau, la virole secondaire et la plaque à tubes étant trois ensembles indépendants et démontables, caractérisé en ce que : - la virole secondaire (7) se termine, à sa partie inférieure, par un pédoncule annulaire (20) comportant d'une part une double portée conique (21, 22) coopérant par deux joints toriques (24) avec une rainure femelle (23) à deux portées coniques creusée dans la surface supérieure de la plaque à tubes (13) et d'autre part, à sa périphérie externe, une portée conique (27) associée à un anneau de serrage (26) ; - la boite à eau (6) se termine, à sa partie supérieure, par une bride munie d'une portée plane (28) de raccordement, avec deux joints toriques (28, 29) interposés, à la surface inférieure de la plaque à tubes (13) ; - un système de tirants (25), dont certains (39, 40) traversent des oreilles de manutention (32) en périphérie de la plaque à tubes (13), de goujons (31) implantés dans la bride de la boîte à eau (6) et d'écrous (30), assure, par l'intermédiaire de l'anneau de serrage (26), l'assemblage et le serrage étanche des trois ensembles indépendants précédents. 1. Steam generator, in particular for pressurized water nuclear reactors, comprising in a known manner a water box (6) where hot water leaves the reactor core and then enters a series of heat exchanger tubes (14) , located in a tube plate (13) and extending inside a secondary ferrule (7), traversed by the secondary water, the water box, the secondary ferrule and the tube plate being three sets independent and removable, characterized in that: - The secondary ferrule (7) ends, at its lower part, by an annular peduncle (20) comprising on the one hand a double conical bearing (21, 22) cooperating by two O-rings (24) with a female groove (23 ) with two conical surfaces hollowed out in the upper surface of the tube plate (13) and on the other hand, at its outer periphery, a conical surface (27) associated with a clamping ring (26); - the water box (6) ends, at its upper part, with a flange provided with a flat bearing surface (28) for connection, with two O-rings (28, 29) interposed, on the lower surface of the plate to tubes (13); - a system of tie rods (25), some of which (39, 40) pass through handling lugs (32) on the periphery of the tube plate (13), of studs (31) installed in the flange of the water box ( 6) and nuts (30), ensures, by means of the clamping ring (26), the assembly and tight tightening of the three preceding independent assemblies. 2. Générateur de vapeur selon la revendication 1, caractérisé en ce que les oreilles de manutention (32), implantées en périphérie de la plaque a tubes, comportent des logements (33) dont le profil conique (34) permet de recevoir les collets coniques (35) qui équipent les goujons (31), permettant ainsi lors d'une manoeuvre de démontage de la seule boite à eau, la manutention de l'ensemble plaque à tubes-virole secondaire sans rompre leur étanchéité.2. Steam generator according to claim 1, characterized in that the manuten ears tion (32), located at the periphery of the tube plate, have housings (33) whose conical profile (34) allows to receive the conical collars (35) which equip the studs (31), thus allowing during a disassembly operation of the single water box, handling of the secondary tube-shell plate assembly without breaking their seal.
EP85400504A 1984-03-23 1985-03-15 Steam generator, particularly for a pressurized-water nuclear reactor Expired EP0159232B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR8404563A FR2561753B1 (en) 1984-03-23 1984-03-23 STEAM GENERATOR, IN PARTICULAR FOR A PRESSURIZED WATER NUCLEAR REACTOR
FR8404563 1984-03-26

Publications (2)

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EP0159232A1 true EP0159232A1 (en) 1985-10-23
EP0159232B1 EP0159232B1 (en) 1988-06-08

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US (1) US4683112A (en)
EP (1) EP0159232B1 (en)
JP (1) JPS60213701A (en)
CA (1) CA1225463A (en)
DE (1) DE3563259D1 (en)
FR (1) FR2561753B1 (en)

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8522729B2 (en) * 2008-07-18 2013-09-03 Babcock & Wilcox Power Generation Group, Inc. Contoured flat stud and stud arrangement for cyclone slag taps
US11901088B2 (en) 2012-05-04 2024-02-13 Smr Inventec, Llc Method of heating primary coolant outside of primary coolant loop during a reactor startup operation
US9892806B2 (en) * 2012-05-04 2018-02-13 Smr Inventec, Llc Space saver flanged joint for a nuclear reactor vessel

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2343502A (en) * 1942-10-12 1944-03-07 David E Fields Follower ring for heat exchanger dome plates
FR1228182A (en) * 1958-03-05 1960-08-26 Superheater Co Ltd Improvements to tubular heat exchangers
DE1119884B (en) * 1960-09-30 1961-12-21 Licentia Gmbh Tube bundle heat exchanger
DE7312164U (en) * 1974-04-18 Siemens Ag Steam generator for nuclear power plants

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Publication number Priority date Publication date Assignee Title
US2807445A (en) * 1954-06-16 1957-09-24 Griscom Russell Co Heat exchanger welded tube joint
JPS4936279U (en) * 1972-07-06 1974-03-30
JPS5381470U (en) * 1976-12-09 1978-07-06
US4162191A (en) * 1977-04-29 1979-07-24 Alexander Cella Modular steam generator for use in nuclear power plants
FI60441C (en) * 1977-07-12 1982-01-11 Hans Viessmann FOERBINDELSEANORDNING FOER VAERMEPANNA
FR2462003A1 (en) * 1979-07-24 1981-02-06 Commissariat Energie Atomique NUCLEAR BOILER

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE7312164U (en) * 1974-04-18 Siemens Ag Steam generator for nuclear power plants
US2343502A (en) * 1942-10-12 1944-03-07 David E Fields Follower ring for heat exchanger dome plates
FR1228182A (en) * 1958-03-05 1960-08-26 Superheater Co Ltd Improvements to tubular heat exchangers
DE1119884B (en) * 1960-09-30 1961-12-21 Licentia Gmbh Tube bundle heat exchanger

Also Published As

Publication number Publication date
EP0159232B1 (en) 1988-06-08
FR2561753A1 (en) 1985-09-27
FR2561753B1 (en) 1986-07-04
JPS60213701A (en) 1985-10-26
US4683112A (en) 1987-07-28
JPH0578722B2 (en) 1993-10-29
DE3563259D1 (en) 1988-07-14
CA1225463A (en) 1987-08-11

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