EP0636834A1 - System and process for cleaning of a steam generator with a waterlance - Google Patents

Abstract

This system is of the type comprising a carriage (40) which is movable on a rail (12) and bears a number of oscillating nozzles (47 and 49). According to the invention, the carriage (40) consists of: a) a first sub-assembly (A) consisting of a reversible jetting module (42) which, bearing the nozzles (47, 49), is equipped, at each of its ends, with a male hydraulic connection (65) which is capable of being connected either to a circuit (129) of water under pressure or to the following module (43); b) and a second sub-assembly (B) consisting of: b1) a module for attaching (43) and driving rotationally the nozzles, b2) a reversible module for observation and detection (44), b3) an autonomous translation module (45) consisting of at least two motorised toothed wheels (118) capable of meshing with the racks (16) of the rail. <IMAGE>

Description

The invention relates to an installation for cleaning, by pressurized water jets, sludge or various waste accumulating on the tube plate and at the base of the tubes of the tube bundle of the secondary circuit of a heat exchanger, and, more particularly, a steam generator of a pressurized water nuclear reactor.

It relates more specifically to steam generators in which the tubes of the tube bundle are distributed in a triangular pitch, that is to say offset by half a pitch from one layer of the bundle to the next layer.

The cleaning operation is carried out, when the generator is stopped, by introducing appropriate means into the central water supply separating the tube bundle above the tube plate, that is to say in an environment with a high ionizing dose rate. This operation requires limiting the intervention time to reduce the time of exposure of personnel to ionizing radiation.

FR-A-2 352 269 describes a cleaning method combining, on the one hand, a circumferential stream of water, sweeping the sludge against the wall of a skirt surrounding the tubular bundle and, on the other hand, bringing them towards a suction device, and a lance moved step by step and provided with nozzles delivering water jets in the intervals between tubes of the bundle to put the sludge in suspension and drive them towards the circumferential current. This technique of cleaning by the mechanical effect of high pressure water jets is commonly called "high pressure launching".

The various means generating the current and the water jets, as well as the suction means, are introduced into the generator through fist holes made in diametrically opposite flanges and projecting radially outside the cylindrical body of the generator. steam.

FR-A-2 684 482 in the names of the applicants describes a high pressure launching device in which the nozzles, oscillating around a horizontal axis and angularly oriented in the horizontal plane in the three directions of the triangular pitch, are carried by a carriage which, mobile on a rail passing through the generator and clamped on it, is provided with electrical and hydraulic connection means, carries means for positioning the jets in alignment with the intervals or laies between tubes and is connected to means suitable for move it step by step. In FR-A-2 684 482, these displacement means consist of a toothed belt, or other equivalent means, the two strands of which are arranged parallel along the guide rail and pass right through the skirt surrounding the tube bundle , but also the generator body. The drive and return of the belt are ensured by suitable wheels arranged outside the generator. The installation of the belt requires numerous manipulations, both when installing on the side of the cold compartment of the generator, and when installing on the side of the hot compartment of this generator, this latter installation also involving a reversal of the carriage so that the nozzles are turned away from the separating plate between the two compartments.

These manipulations increase the assembly time and above all require carrying out pulling and guiding operations of the belt in each of the generator compartments, that is to say in the most contaminated area.

One of the objects of the invention is to provide a cleaning installation which is easy to install and minimizes the intervention times of the personnel in an environment with a high rate of ionizing dose in order to limit their exposure to radiation.

• a) Un premier sous-ensemble composé d'un module réversible de lançage qui, portant les buses, est muni, à chacune de ses extrémités, d'un raccord hydraulique mâle saillant longitudinalement, ces deux raccords étant aptes à être raccordés, chacun, soit à un circuit externe d'amenée d'eau sous pression, soit au module suivant, et communiquant avec un circuit commun d'alimentation des buses, circuit traversant de part en part le corps du module,
• b) et un second sous-ensemble composé :
  • b1) d'un module d'accrochage et d'entraînement en rotation comportant, en vis-à-vis du module de lançage, d'une part, des moyens de connexion automatique et d'obturation aptes à coopérer avec l'un ou l'autre des raccords hydrauliques du module de lançage, et, d'autre part, à son autre extrémité, de moyens frontaux de connexion électrique avec le module suivant,
  • b2) d'un module réversible d'observation et détection muni de capteurs optiques, apte à coopérer au moins avec les tubes du faisceau tubulaire, de moyens de vision, et de moyens frontaux de connexion électrique avec les modules, respectivement, suivant et précédent
  • b3) et d'un module autonome de translation comportant au moins deux roues dentées motorisées aptes en engrener avec les crémaillères du rail, un boîtier de connexion avec des circuits électriques de commande et de puissance, et des moyens frontaux de connexion électrique avec le module précédent.

To this end, in the installation according to the invention, each section of the rail carries two racks, while the carriage is composed of several elements assembled to each other in a removable manner and forming two sub-assemblies, namely:

• a) A first sub-assembly composed of a reversible launching module which, carrying the nozzles, is provided, at each of its ends, with a male hydraulic connection projecting longitudinally, these two connections being capable of being connected, each, either to an external pressure water supply circuit, or to the next module, and communicating with a common nozzle supply circuit, circuit passing right through the module body,
• b) and a second subset composed:
  • b1) an attachment and rotation drive module comprising, facing the launching module, on the one hand, automatic connection and shutter means capable of cooperating with one or the other of the hydraulic connections of the launching module, and, on the other hand, at its other end, frontal means of electrical connection with the following module,
  • b2) of a reversible observation and detection module provided with optical sensors, able to cooperate at least with the tubes of the tube bundle, vision means, and frontal means of electrical connection with the modules, respectively, next and previous
  • b3) and of an autonomous translation module comprising at least two motorized toothed wheels capable of meshing with the rail racks, a connection box with electrical control and power circuits, and frontal means of electrical connection with the module previous.

It appears from the above that the carriage is composed of a first sub-assembly, connecting to the hydraulic circuit, and a second sub-assembly, connecting to the electrical circuits and comprising the drive means of the carriage, the means for driving the nozzles and the means for positioning the carriage.

Thanks to their structure, the two sub-assemblies are quickly installed on the rail and require no intervention to ensure their connection, which can therefore be done automatically. This allows the evacuation of personnel as soon as the subassemblies are mounted on the rails and connected to their respective circuit, hydraulic or electric.

After cleaning a compartment, the separation of the two sub-assemblies is also automatic, so that recourse to human intervention is essential only when each of the sub-assemblies has returned to its starting point.

• a) - à positionner le rail contre la paroi verticale de séparation du faisceau tubulaire et à le caler dans ses moyens de guidage,
• b) - à monter le module de lançage du premier sous-ensemble à l'une des extrémités du rail, puis à raccorder ce module à son circuit hydraulique, alors non alimenté,
• c) - à monter le second sous-ensemble à l'autre extrémité du rail puis à le raccorder à son circuit électrique de puissance et de commande,
• d) - à commander, à partir du poste de commande, le déplacement du second sous-ensemble en direction du premier sous-ensemble jusqu'à l'engagement de la cage à bille du module d'accrochage et d'entraînement en rotation sur l'embout du raccord hydraulique du module de lançage, puis à assurer le verrouillage de ces deux éléments pour assurer la liaison des deux sous-ensembles du chariot,
• e) - à commander le déplacement en sens inverse du chariot et à l'alimenter en eau sous pression pendant toute la phase de nettoyage,
• f) - à la fin de la course de nettoyage, à ramener le chariot du côté comportant le circuit hydraulique d'alimentation,
• g) - à désolidariser les deux sous-ensembles et à ramener le second sous-ensemble à sa position de départ, de l'autre côté du générateur,
• h) - après extraction des deux sous-ensembles hors du rail, démontage du rail, remontage et bridage du rail dans l'autre compartiment du générateur, à déconnecter le module de lançage de son circuit hydraulique, a le retourner sur lui-même de 180°, à le connecter par son autre embout sur son circuit hydraulique et à l'introduire sur le rail dépassant du même trou de poing,
• i) - à désolidariser le module d'observation et de détection des deux autres modules du second sous-ensemble, à retourner ce module sur lui-même de 180°, puis à le solidariser à nouveau avec les deux autres modules du second sous-ensemble et à introduire ce sous ensemble sur le rail dépassant du même trou de poing,
• j) - et à assurer le nettoyage du deuxième compartiment en répétant les opérations d) à f).

The invention also relates to the method of implementing this installation. This process consists, after the known phase of assembling the sections of the rail as and when they are placed in one of the compartments of the generator:

• a) - positioning the rail against the vertical wall separating the tube bundle and wedging it in its guide means,
• b) - mounting the launching module of the first sub-assembly at one of the ends of the rail, then connecting this module to its hydraulic circuit, then not supplied,
• c) - mounting the second sub-assembly at the other end of the rail and then connecting it to its electrical power and control circuit,
• d) - to control, from the command post, the movement of the second sub-assembly in the direction of the first sub-assembly until the engagement of the ball cage of the attachment and rotation drive module on the end of the hydraulic connection of the launching module, then ensuring the locking of these two elements to ensure the connection of the two sub-assemblies of the carriage,
• e) - order the carriage to move in the opposite direction and supply it with pressurized water during the entire cleaning phase,
• f) - at the end of the cleaning stroke, bring the carriage back to the side comprising the hydraulic supply circuit,
• g) - to separate the two sub-assemblies and to bring the second sub-assembly back to its starting position, on the other side of the generator,
• h) - after extraction of the two sub-assemblies out of the rail, disassembly of the rail, reassembly and clamping of the rail in the other compartment of the generator, to disconnect the launching module from its hydraulic circuit, to turn it over on itself 180 °, to connect it by its other end to its hydraulic circuit and to introduce it on the rail protruding from the same fist hole,
• i) - to separate the observation and detection module from the two other modules of the second sub-assembly, to turn this module on itself by 180 °, then to re-join it again with the two other modules of the second sub- together and introduce this sub-assembly on the rail protruding from the same fist hole,
• j) - and to ensure the cleaning of the second compartment by repeating operations d) to f).

Thanks to this process, moving the active equipment from the installation from the first to the second compartment of the generator does not require moving the electrical and hydraulic supply circuits which therefore maintain their position, and do not require, in addition to dismantling and reassembly of the rail, than turning the launching and observation modules on themselves, respectively, which requires little time. As a result, the compartment change maneuver is also carried out quickly and, compared with prior art installations, limits the time of exposure of personnel to radiation.

• Figure 1 est une vue partielle en perspective avec arraché partiel d'un générateur de vapeur dans la phase de mise en place du rail de l'installation,
• Figure 2 est une vue similaire à la figure 1 mais montrant l'installation montée,
• Figure 3 est une vue de côté avec coupe partielle montrant l'ensemble des éléments de l'installation lorsqu'ils sont mis en place,
• Figure 4 est une vue de face en bout, montrant, plus en détails, une forme d'exécution des moyens de maintien de guidage du rail sur l'une des brides du corps de générateur,
• Figure 5 est une vue partielle en coupe, suivant V-V de figure 3, montrant, à échelle agrandie, le rail et le module autonome de translation,
• Figure 6 est une vue en perspective montrant, à échelle réduite, les éléments essentiels du chariot,
• Figure 7 est une vue en perspective montrant les différents éléments constituant le chariot lorsqu'ils sont désolidarisés les uns des autres,
• Figures 8 et 9 sont des vues en coupe longitudinale dans deux plans décalés de 90 ° montrant, plus en détails, le module de lançage,
• Figure 10 est une vue en coupe longitudinale du module d'accrochage et d'entraînement en rotation dans sa phase d'approche du module de lançage,
• Figure 11 est une vue de face en bout suivant la flèche XI de figure 10 du module d'accrochage et d'entraînement en rotation,
• Figure 12 est une vue en coupe suivant XII-XII de figure 3, montrant quelques unes des phases de la mise en oeuvre de l'installation.

Other characteristics and advantages will emerge from the description which follows with reference to the appended diagrammatic drawing, representing by way of nonlimiting example, an embodiment of the installation.

• FIG. 1 is a partial perspective view with partial cutaway of a steam generator in the installation phase of the installation rail,
• FIG. 2 is a view similar to FIG. 1 but showing the installation installed,
• FIG. 3 is a side view with partial section showing all of the elements of the installation when they are put in place,
• FIG. 4 is a front end view, showing, in more detail, an embodiment of the means for holding the guide of the rail on one of the flanges of the generator body,
• FIG. 5 is a partial sectional view, along VV of FIG. 3, showing, on an enlarged scale, the rail and the autonomous translation module,
• FIG. 6 is a perspective view showing, on a reduced scale, the essential elements of the carriage,
• FIG. 7 is a perspective view showing the various elements constituting the carriage when they are separated from each other,
• FIGS. 8 and 9 are views in longitudinal section in two planes offset by 90 ° showing, in more detail, the launch module,
• FIG. 10 is a view in longitudinal section of the attachment module and of the rotary drive in its approach phase to the launch module,
• FIG. 11 is a front end view along arrow XI of FIG. 10 of the attachment and rotation drive module,
• Figure 12 is a sectional view along XII-XII of Figure 3, showing some of the phases of the implementation of the installation.

In FIGS. 1 and 2, the reference numeral 2 designates the cylindrical body of a steam generator, 3 the skirt of its exchanger, 4 one of the branches of a tubular bundle in the shape of a "U", the two branches of which are separated by a vertical plate 5 extending over almost the entire height of the generator. 6 designates the tubular plate, 7 the spacer plates ensuring the spacing of the tubes 8 making up the tubular bundle 4, and 7a the flow distribution plate near which the rail 12 of the installation is disposed.

In known manner, the water box 6 communicates with the tubes of the tube bundle and is part of the primary circuit of the reactor. The space 9, between the skirt 3 and the tube bundle 4, is occupied, during operation, by the secondary coolant of the reactor and therefore forms part of the secondary circuit. For maintenance, repair and cleaning work, this part of the steam generator is drained.

Finally, 10 denotes two fist holes, diametrically opposite, formed in the body of the generator and the flanges 10a of which are used for fixing the means for holding the cleaning installation. These holding means are generally constituted by a rail 12, the different sections of which are engaged in the central water ru 13 by passing through openings 14, formed in the skirt 3 and coaxial with the fist holes 10.

As shown in more detail in FIG. 5, each rail section 12 has, in cross section, the shape of an inverted "U", with unequal wings, that is to say comprising a small wing 12a and a large wing 12b extended downwards by a gutter 15, the usefulness of which will be specified below. Its core 12c is integral with two internal racks 16, pressed against these wings and spaced apart to delimit, between them, a longitudinal slide 17. This core is also integral with an upper reinforcement flat 18 fixed against its external face and extending over its entire length. Figure 5 shows that the longitudinal edges of this flat protrude from the wings 12a and 12b of the rail section and each comprise at least one bevel 19 turned downwards.

Each rail section is provided with means, not shown, ensuring its connection with the following and / or previous sections to form a continuous rectilinear rail passing right through the cylindrical body 2 and protruding on either side of the flanges 10a of these fist holes, as shown in Figure 3.

The rail, thus formed, is held on the above-mentioned flanges 10a by means which will now be described with reference to FIGS. 1, 2, 3 and 4.

Each of these means is composed of a console 22, a first vertical frame 23, a second vertical frame 24, and a plate 25.

The plate 25, which is pressed against the face of the flange 10a surrounding the fist hole 10, is fixed to this flange by screws 26 and is provided with a centering collar positioning it in the fist hole. This plate carries two horizontal and spaced slides 27 between which the second vertical frame 24 can slide horizontally, provided with locking means in position and in particular with transverse screws 28.

The first vertical frame 23 is mounted to slide vertically in the second vertical frame. This frame is integral with the console 22 composed of two cheeks. The two cheeks are connected, in the upper part and below the upper cross member 24a of the second vertical frame 24, by a cross member 29 into which the end of a threaded rod 30 is screwed, mounted free in rotation but locked in translation in the aforementioned crosspiece 24a of the frame 24. This threaded rod makes it possible to adjust the vertical position of the frame 23.

Each console carries pairs of rollers 32, of horizontal axes, able to come into contact with the upper face of the flat 18 of the rail sections, as shown in FIG. 4, but also at least two sets of rollers 33, of oblique axes, able to come into contact with the bevelled longitudinal faces 19 of this flat.

Finally, each console comprises means for wedging the rail in translation, constituted by a movable vertical finger 34 (FIG. 3) able to be engaged in a vertical perforation 35 formed in the flat 18 of each end rail section. In the embodiment shown, this finger is associated with means for prestressing the rail and for this purpose is carried by a slide 36, itself mounted sliding in the console 22, above the rail. In a cross member 37, formed at the external free end of the console 22, an adjustment screw 38 is screwed, the end of which is linked in translation, but mounted free in rotation in the slide 36. This screw is arranged longitudinally, parallel to the general direction of rail 12.

With these means for positioning and holding the rail, when the rail has been introduced into each of its two holding means, its positioning is ensured, first by moving it transversely, so that its large wing 12b comes into contact with the separation plate 5 of the tube bundle 4, then, after setting the second vertical frame 24 by the screws 28, bringing the upper face of the flat 18 to the contact of the distribution plate 7a, as shown in FIG. 5, by actuation of the screw 30. At this stage, the rail is prestressed by displacement of one of the slides 36, in the direction of the arrow 39 in FIG. 3. In this way, the central part of the rail which, by its own weight, tends to bend downwards, is pressed over practically its entire length against the distribution plate 7a. The rail thus has better straightness and the rigidity required to guide the carriage 40 forming part of the cleaning installation.

• un premier sous-ensemble A composé d'un module réversible de lançage 42,
• et un second sous-ensemble B composé d'un module d'accrochage et d'entraînement en rotation 43, d'un module réversible d'observation et de détection 44 et d'un module autonome de translation 45.

This carriage 40 is composed of several elements assembled to each other in a removable manner, and forming two sub-assemblies, namely:

• a first sub-assembly A composed of a reversible launching module 42,
• and a second sub-assembly B composed of an attachment and rotation drive module 43, a reversible observation and detection module 44 and an autonomous translation module 45.

As shown in more detail in FIG. 6, at least the modules 42-43 and 45 are provided, in the upper part, with guide shoes 46 able to cooperate with the slide 17 delimited between the two racks 16 of the rail sections.

These pads, which are fixed on the upper part of the modules, are made of material having a good coefficient of friction, and for example of polyethylene.

As shown in Figures 6 and 7, and in more detail in Figures 8 and 9, the launch module 42 carries, in its central part, three nozzles 47, capable of emitting three parallel jets perpendicular to the direction of movement of the carriage and oscillating in the vertical plane, and two lateral nozzles 49, capable of emitting divergent jets 50. Each of these jets 50 is inclined relative to the longitudinal axis of the body 52, so as to come into the oblique lanes for separating the tubes 8 from the tube bundle 4 with triangular steps. The nozzles 47 are carried by a hollow shaft 53 mounted to rotate freely in the body 52 and carrying at each of its ends conical bevel gears 54. This shaft is integral with a toothed wheel 55 meshing with a pinion 56 wedged on a longitudinal shaft 57, which passes right through the body 52 and is mounted to rotate freely therein. The ends of the shaft 57, which protrude from the body 52, are each provided with a coupling member 58 capable of cooperating with means complementary to the actuation and rotation drive module 43.

Each of the side nozzles 49 is carried by a hollow shaft 59, mounted to rotate freely in the body 52 and comprising a toothing 60. This toothing meshes with a pinion 62 wedged on a deflection shaft 63, which is provided with a conical pinion 64 meshing with one of the aforementioned bevel gears 54.

It follows from the above that any rotational movement communicated to the shaft 57 is transmitted to the central hollow shaft 53, then, by the various references, to the two hollow shafts 59, so that all the nozzles 47 and 49 are animated by the same oscillating movements in the vertical plane, both in direction and in value.

The essential originality of this module is that its supply of hydraulic fluid is ensured by two male hydraulic connections 65, projecting longitudinally from each of its end faces. Each connector communicates, through a housing 66 and a transverse channel 67, with a longitudinal channel 68, common to the two connectors and extending over the entire length of the body 52. FIG. 8 shows that the channel 68 communicates, through a transverse channel 69, with a chamber 70 ensuring the supply of the hollow shaft 53 and, consequently, of the nozzles 47. As for FIG. 9, it shows that each of the end housings 66 of the body 52 communicates, by a longitudinal bore 72, with a chamber 73 for supplying the hollow shaft 59, carrying the corresponding nozzle 49.

It appears from the above that, whatever the hydraulic connection 65 connected to the pressurized water supply network, all of the nozzles are perfectly supplied.

Of course, the hollow shafts are associated with seals which need not be detailed in the present description.

Each of the fittings 65 is integral with a socket 74 having a radial arm 75 at the free end of which is disposed a contact finger 76. Figures 7, 8 and 9 show that the arms 75, arranged at the two ends of the module 42 , are inclined in the same way so that the fingers 76 are aligned on the same longitudinal axis, while being arranged laterally on one of the sides of this module.

FIG. 10 shows that the module 43 for hooking and driving in rotation comprises, opening from its face facing the launching module 42, on the one hand, automatic connection and shutter means capable of cooperating with one or the other of the hydraulic connections 65, and on the other hand, a member 77 for rotationally connecting with one or the other of the coupling means or members 58 of the module 42.

The connecting member 77 is constituted by a socket carrying an eccentric finger 78 able to penetrate into an eccentric housing 79 formed at the end of each of the coupling members 58 of the launch module 42. The socket 77 is wedged at the 'one end of a longitudinal shaft 80, mounted to rotate freely in the body 82 of the module 43. The other end of the shaft 80 is connected, by a gear train 83, to the output shaft of an electric motor 84, disposed substantially axially in the body 82.

The shaft 80 is also linked in rotation to a potentiometer 81, arranged in its extension and making it possible to know, at any time, its angular position, therefore the position given in the vertical plane to the launching nozzles 47 and 49.

The automatic connection means comprise a ball cage 85 and a locking ring 86. The ball cage, also constituting means for closing the hydraulic circuit passing through the body of the module 42, comprises a blind axial bore 87, capable of receiving the 'end piece 65a of one or other of the fittings 65. In this bore, open radial holes constituting housings for balls 88 capable of penetrating into the groove 65b with which each end piece 65a of the fittings 65 is provided. This cage is linked in translation to the body 82 by a screw 89 and is locked in rotation by a finger 90.

The locking ring 86 comprises, on the one hand, near its outer end, an inclined ramp 86a tending to drive the balls 88 inside the ball cage, and, on the other hand, at its other end , an internal thread 92 and an external toothing 93. The thread 92 is screwed onto a complementary thread formed at the internal end of the ball cage 85, while the toothing 93 meshes with a pinion 94 wedged on the shaft of an electric motor 95. This pinion is also linked, by a shaft 96, to a manual control wheel 97.

It is easy to see that, under the action of the rotation communicated to it by the pinion 94 and by pressing on the thread of the ball cage 85, the ring 86 can move longitudinally in one direction or the other, depending on the direction of rotation of the motor 95, to force the balls 88 to engage in the groove 65b or, on the contrary, release these balls by allowing the extraction of the nozzle 65a. In case of failure of the motor 95 or, if necessary, the locking and unlocking of the hydraulic connection can be carried out manually by the thumb wheel 97.

This automatic locking device is associated with a device for controlling its operation composed of a finger 98, pressed by a return spring 99 against the ring 86, and of a rod 100, one end of which is integral with finger 98 and the other end of which is integral with a mass 102 which can be detected by a position sensor 103.

The various electrical circuits supplying the electric motors or coming from the position sensors, lead to a connector 104 disposed frontally on the end of the module 43 which is opposite to that comprising the automatic connection means. This end is also provided with connection means with the following module composed of a fixing flange 105 comprising a threaded bore 106 for a vertical screw and a smooth bore 107 for a longitudinal screw 108.

Finally, as shown in FIG. 11, the module 43 comprises, at its front face turned towards the side of the launching module 42, two sensors 110 arranged on either side of its vertical median plane. Each of these sensors is intended to cooperate with one of the contact fingers 76 carried by the connections 65 of the module 42 to detect the position, right or left, of this module 42. Each of the sensors 110 also detects, by contact with the corresponding finger 76, that the modules 42 and 43 are in the correct connection position, that is to say that the end piece 65a of the hydraulic connection 65 is properly engaged in the ball cage 85, and that consequently, the automatic connection can be launched.

The reversible observation and detection module 44, shown in FIGS. 6 and 7, comprises, on the side of one of its longitudinal faces, an optical sensor 112, capable of cooperating with the tubes 8 of the first row of the tube bundle 4, and two optical sensors 113, capable of cooperating with positioning marks arranged in the consoles 22.

It also includes vision means, such as video cameras or the like, protected by a protector 114. This module therefore only has the function of ensuring the detection of the position of the carriage and the observation of cleaning.

Each of its front faces is provided with a connector, respectively 115 and 116, capable of being plugged in, either with the connector 104 of the module 43, or with the connector 117 of the module 45.

The autonomous translation module 45 essentially comprises two toothed wheels 118, each capable of meshing with the racks 16 of the rail 12. These two wheels are wedged on a transverse horizontal shaft 119 which is linked in rotation to an electric motor, not shown. This connection comprises a disengageable member, actuable by a pull tab 120 projecting from the free front face of any connector of the module 45.

In the embodiment shown, the module 45 also includes a coding wheel 122 meshing with one of the racks 16 and making it possible, by known means, to detect the longitudinal position of the carriage on the rail.

To ensure its connection with the reversible observation and detection module 44, the translation module 45 is provided (FIG. 7), at one of its ends, with a flange 123 comprising, like the flange 105 of the module 42 , a vertical threaded bore 106 and a smooth longitudinal bore 107.

Thanks to this arrangement, when the reversible observation and detection module 44 is assembled with the modules 43 and 45, by plugging in the various connection means, the connection of the three elements constituting the second sub-assembly B is made positive by setting places, on each side of the module 44, on the one hand, horizontal screws 108 in the longitudinal bores 107 of the flanges, respectively 105 and 123, and, on the other hand, by placing vertical screws 124. Each of these screw 124 passes through a bore 125, formed in a tab 126 projecting from the end of the module 44, and is screwed into the threaded bore 106 of the flange of the underlying module 43 or 45. It will be noted that the connection of the module d observation 44 is only ensured by four screws, which considerably reduces assembly and disassembly operations, when it is necessary to turn it over to clean the other compartment of the generator, as will be explained below.

Finally, and as shown in more detail in FIGS. 5 and 6, the autonomous translation module 45 carries a connection box 127 to which end all the electrical control, power and detection circuits, coming from the other two modules 43 and 44 This box is articulated relative to the longitudinal axis of the carriage, so as to be able to occupy two symmetrical positions shown, one in strong lines, and the other in dashed lines in FIG. 5.

Thanks to this arrangement, and whether the carriage is placed to the right of the rail or to the left of it, depending on whether it is mounted in one or the other of the compartments of the generator, the housing 127 can be pivoted so that the cable bundle 128, which ends there and which goes to a control station disposed outside the contaminated zone, slides in the gutter 15, integral with the rail 12.

For the purposes of the description of the installation implementation process, described above, description which will be given with reference to Figures 3 and 12, the first compartment which will be subjected to the cleaning operation is designated by the reference I, while the second compartment is designated by the reference II. Similarly, the side corresponding to the fist hole 10 through which the first sub-assembly A is introduced is designated C1, while the side comprising the fist hole through which the second sub-assembly B is introduced is designated by C2.

The installation of the installation and its adaptation for transfer to the other compartment are ensured by two operators working substantially, one near C1 and the other near C2.

To clean the compartment I, and after installing the means for fixing and holding the rail in each of the fist holes 10, installing the rail 12 and prestressing this rail, the water supply circuit 129 under pressure is brought into C1 by an operator, while, simultaneously, the cable 128 of electrical connection between the control station, not shown, and the sub-assembly B, is arranged on the side C2 by another operator. It is then proceeded to the installation of the module 42, constituting the sub-assembly A, on the end of the rail protruding from the console 22 arranged on the side C1, then, to the establishment of the sub-assembly B at the other end of the rail protruding from the side C2. After connection in C1 of the hydraulic circuit 129 on the end piece 65a of the hydraulic connection 65 of the launching module 42, and connection in C2 of the electric cable 128 on the housing 127 of the translation module 45, the personnel can leave the contaminated zone and join an uncontaminated sector until the compartment change operation.

Indeed, from this stage, all the maneuvers can be directed from the control station. Thus, it is from the control station that the autonomous translation module is controlled so that its toothed wheels 118, meshing with the racks 16, move the whole of the sub-assembly B in the direction of C1, until the ball cage 85 covers the end piece 65a of the hydraulic connection of the module 42 in standby at C1, and that the finger 76 associated with this end piece comes into contact with one of the sensors 110 of the module 43, for attachment and drive in rotation. At this stage, the automatic attachment of the two sub-assemblies A and B is carried out by displacement of the sleeve 86. When this attachment is finished, and the sensor 103 indicates that it is correctly carried out, the whole of the carriage 40 is moved in the opposite direction, by the autonomous translation module 45, that is to say going from C1 to C2. As soon as the launch module 42 enters the area to be cleaned, the circuit 129 is supplied with pressurized water and the movement of the carriage is carried out step by step, under control of the control station from the information positioning data, on the one hand, by the optical sensor 112, and, on the other hand, by the coding wheel 122.

At the end of this cleaning phase, the whole of the carriage 40 is brought back to C1 then, after the sub-assembly A has been automatically disconnected from the sub-assembly B, this sub-assembly B is brought back to C2.

It is only at this stage that the personnel intervene again to take the two sub-assemblies out of the rail 12, extract this rail from compartment I to put it back in compartment II while ensuring its positioning, its setting and its prestressing .

At this stage, the launching module 42 is replaced on the rail 12 after having been pivoted on itself by 180 °, as shown by the arrow 130 on the right part of FIG. 12. As for the sub-assembly B , before being replaced on the rail 12, it is first prepared by ensuring the separation of the module 44 from the other modules 43 and 45, then, as shown on the left side of FIG. 12 by the arrow 131, the 180 ° reversal of the module 44 on itself, so that its optical sensors 112-113 are turned towards the tube bundle 4 of compartment II. Then, the module 44 is again mechanically linked to the modules 43 and 45, by fitting and tightening the screws 108 and 124. As soon as the sub-assembly B is put in place on the end C2 of the rail 12, the personnel can again move away from the contaminated area, leaving it to the control station to manage the following phases of connection, cleaning and disconnection, which take place in the same way as for compartment I.

In the event of failure of the electric motor ensuring the drive of the toothed wheels 118 cooperating with the racks 16, that is to say in the event of untimely stopping of the carriage 40 during the cleaning phase, therefore inside the generator compartment , failure resulting in the blocking of the carriage with respect to the rack, the personnel can, by means of a hook pole engaged by the fist hole arranged on the side C2, actuate the release lever 120, so as to disengage the toothed wheels of their drive means, then continuing to pull on the pole, slide the entire carriage in its slide until it comes out through the corresponding fist hole. This troubleshooting operation requires simple means and allows rapid intervention limiting the staff exposure time.

The declutching is also used to facilitate the introduction of the sub-assembly on the rail to its starting position, since it allows the toothed wheels to pivot freely, without having to drive the armature of the electric motor.

It will be noted that, in this installation, not only the elements constituting the carriage 40 are organized so as to minimize the connection and turnaround times, but also that the means for positioning the rail 12 in each of the compartments I and II and those for positioning the carriage 40 on the rail, are organized to reduce handling and adjustment times. In addition, the assignment to a subset A of an essentially hydraulic function and to the other subset B of essentially electrical functions makes it possible to arrange the circuits, respectively, hydraulic and electrical, on one side of the generator. This advantage, combined with the possibility of turning over on themselves, respectively of the launching module 42 and of the module 44, of observation and detection, avoids, during the compartment change phase, having to carry out displacements. of material from side to side of the generator, and also reduces the time for changing compartments.

It appears from the above that this installation, by its structure and by its mode of implementation, makes it possible to reduce its installation time and its time for changing compartments, by at least half compared to an installation. and limit the time exposed to ionizing radiation by the personnel assigned to these tasks.

Claims (16)

Installation for cleaning the tube plate of a steam generator of the type comprising: - a remote control station from the steam generator, - means attaching to the flanges of two opposite fist holes (10) of the generator to hold and guide a rail (12) arranged in the central water supply (13) of the tubular bundle (4) of this generator, - a carriage (40) movable on the rail (12) and carrying several nozzles (47 and 49) oscillating in three vertical planes, means for positioning the carriage relative to the beams of the bundle, - And motor means able to move the carriage (40) on the rail, characterized in that each section of the rail (12) carries two racks (16), internal and spaced, while the carriage (40) is composed of several elements assembled in a removable manner and forming two sub-assemblies, namely: a) a first sub-assembly (A) composed of a reversible launching module (42) which, carrying the nozzles (47, 49), is provided, at each of its ends, with a male hydraulic connection (65) protruding longitudinally, these two connections being able to be connected, each, either to an external circuit (129) for supplying pressurized water, or to the following module (43), and each communicating with a common supply circuit ( 67 to 73) nozzles (47-49), circuit passing right through the module body, b) and a second subset (B) composed: - b1) of an attachment and rotation drive module (43) comprising, facing the launch module (42), on the one hand, means (85-86) of automatic connection and shutter capable of cooperating with one or the other of the hydraulic connections (65) of the launching module (42), and, on the other hand, at its other end, front means (104) of electrical connection with the following module (44), - b2) of a reversible observation and detection module (44) provided with optical sensors (112-113), able to cooperate at least with the tubes of the tube bundle (4), vision means, and frontal means (115-116) of electrical connection with the modules, respectively, according to (45) and previous (43), - b3) and of an autonomous translation module (45) comprising at least two motorized toothed wheels (118) suitable for mesh with the racks (16) of the rail, a box (127) for connection with electrical, control and power circuits, and front means (117) for electrical connection with the previous module (44). Installation according to claim 1, characterized in that each rail section (12) has, in cross section, the shape of an "U" turned over with uneven wings (12a-12b) and the racks (16), fixed against the internal face of its core (12c), delimit between them a longitudinal slide (17) for pads (46) for guiding in translation secured to the carriage (40). Installation according to any one of claims 1 to 2, characterized in that the rotation connection, between the toothed wheels (118) of the autonomous translation module (45) and their electric drive motor, comprises a disengageable member actuable by a pull tab (120) projecting longitudinally from the non-connectable end of the module (45). Installation according to any one of claims 1 to 3, characterized in that the electrical connection means of the autonomous translation module (45) consist of a longitudinal housing (127) which, articulated under the body of the module around a longitudinal axis, can occupy two opposite lateral positions, while the large wing (12b) of the "U" profile of the rail (12) is extended by a gutter (15) open upwards and capable of receiving the part of the housing protruding connection of the module (45) and the bundle (128) of electrical conductors which leads to this housing. Installation according to claim 1 and any one of claims 2 to 4, characterized in that the autonomous translation module (45) and the attachment and rotation drive module (43) comprise, each and at their end. facing the observation module (44), a fixing flange (123, 105), while the means of connection of each of the two ends of the reversible observation and detection module (44) with the aforementioned flanges comprise, for each end, on the one hand, a vertical screw (124) which, passing through a lug (126) projecting longitudinally from the end of the observation and detection module (44), is screwed into the module (43 or 45) disposed under the tab (126) and, on the other hand, a longitudinal screw (108) which, passing through the flange (105 or 123) formed at the end of the module (43 or 45) juxtaposed with the module (44) of observation, is screwed into this observation module. Installation according to any one of claims 1 to 5, characterized in that the means for automatic connection of the module (43) for hooking and driving in rotation (43) comprise: a fixed cage (85) with balls (88) capable of receiving the end piece (65a) of one or other of the hydraulic connections (65) projecting from the launching module (42), - A locking ring (86) which, arranged coaxially around the cage (85) and comprising a ramp (86a) tending to drive the balls from the cage into the groove (65a) of the end piece, is connected to means motors (95, 97) able to move it longitudinally between a rest position, in which it releases the balls, and a locking position, in which it projects the balls inside the cage. Installation according to claim 6, characterized in that the motor means of the locking ring (86) comprise, on the one hand, an electric motor (95) driving a pinion (94) meshing with a toothing (93) formed at the periphery of the ring (86), and, on the other hand, a threaded connection (92) which, formed between the ring (86) and the fixed cage (85), transforms the rotation of the ring in longitudinal translation. Installation according to any one of claims 1 to 7, characterized in that the hooking and driving module (43) comprises, mounted to rotate freely in its body, a motorized longitudinal shaft (80), the projecting end of which of the front face of the body, facing the launching module (42), is integral with a rotating connecting member (77-78) capable of cooperating with one or the other of the two coupling (58) projecting at each end of the launching module (42), these two members being wedged at the ends of a common longitudinal shaft (57), mounted to rotate freely in the body of the launching module (42) and controlling the pivoting of the nozzles, respectively central (47) and lateral (49). Installation according to any one of claims 1 to 8, characterized in that the module (43) for hooking and driving in rotation comprises a sensor (103) detecting at least the locking position of the locking ring (86 ). Installation according to any one of claims 1 to 9, characterized in that the attachment and drive module (43) comprises two sensors (110) which, arranged on its front face facing the translation module (42) and on either side of its vertical median plane, are able to cooperate with one or the other of the two fingers (76) projecting laterally from the hydraulic connections (65) of the launching module (42), to detect the position, right or left, of this launching module (42) and the position of longitudinal engagement in the ball cage (85) of the end piece (65a) of one of the hydraulic connections (65) of this module ( 42). Installation according to any one of claims 1 to 10, characterized in that the core (12c) of the profile of the rail (12) is integral, over its entire length, with an upper reinforcing flat (18) whose edges longitudinal, projecting from its wings (12a-12b), are provided with a bevel (19) to cooperate with trains of guide rollers (32, 33), these rollers being carried by two brackets (22) forming part of the means attaching to the flanges (10a) of two opposite fist holes (10). Installation according to claim 11, characterized in that the console (22) of each of the means attaching to one of the flanges (10a) of the fist holes (10) is integral with a first vertical frame (23) which, mounted to slide vertically in a second vertical frame (24), is connected in translation to one (24a) of the crosspieces of this second frame (24) by a threaded rod (30) for adjusting its position, while the second frame (24) is slidably mounted in horizontal slides (27), carried by a plate (25) fixing on the flange (10a), and is provided with locking screws (28). Installation according to any one of claims 10 to 11, characterized in that the console (22) of each of the means which is fixed to one of the flanges (10a) of the fist holes (10) is provided with a crosspiece ( 36) which, disposed above the rail (12), carries a movable vertical finger capable (34) of being engaged in a vertical bore (35) formed in the reinforcement flat (18) of the last section of rail (12) to wedge this rail in translation. Installation according to claim 13, characterized in that the vertical finger (34) is carried by a slide (36) which, slidingly mounted in the console (22) above the rail (12), is connected to a fixed crosspiece (37 ) of this console by a longitudinal screw (38) for prestressing the rail (12). Method of implementing the installation according to all of claims 1 to 14, characterized in that it consists, after the known phase of assembling the sections of the rail (12) as and when they are put in place in one (I) of the generator compartments (I or II): a) - positioning the rail (12) against the vertical wall (5) of separation of the tube bundle (4) and wedging it in its guide means, b) - mounting the launching module (42) of the first sub-assembly (A) at one of the ends of the rail, then connecting this module (42) to its hydraulic circuit (129), then not supplied, c) - mounting the second sub-assembly (B) at the other end (C2) of the rail (12) and then connecting it to its electrical (128) power and control circuit, d) - to control, from the control station, the movement of the second sub-assembly (B) in the direction of the first sub-assembly (A) until the engagement of the ball cage (85), of the module (43) for hooking and driving in rotation, on the end piece (65a) of the hydraulic connection (65) of the launching module (42), then in ensuring the locking of these two elements to ensure the connection of the two sub -assemblies (A and B) of the carriage (40), e) - controlling the movement in the opposite direction of the carriage (40) and supplying it with pressurized water during the entire cleaning phase, f) - at the end of the cleaning stroke, to bring the carriage (40) back to the side (C1) comprising the hydraulic circuit (129), g) - to separate the two sub-assemblies (A and B) and to bring the second sub-assembly (B) to its starting position on the other side (C2), h) - after extraction of the two sub-assemblies (A and B) out of the rail (12), disassembly of the rail (12), reassembly and clamping of the rail in the other compartment (II) of the generator, to disconnect the module launching (42) of its hydraulic circuit (129), turn it over on itself by 180 °, connect it by its other fitting (65) to its hydraulic circuit (129) and introduce it on the rail (12 ) protruding from the same fist hole, i) - to separate the observation and detection module (44) from the two other modules (43 and 45) of the second sub-assembly (B), to turn this module (44) on itself by 180 °, then to join it again with the other two modules (43 and 45) of the second sub-assembly (B) and to introduce this sub-assembly on the rail (12) projecting from the same fist hole, j) - and to ensure the cleaning of the second compartment (II) by repeating operations d) to f). Method according to claim 15, characterized in that the phase of positioning the rail (12) against the vertical wall (5) of separation of the tube bundle (4) is followed by a phase of prestressing the rail (12) by actuation of the longitudinal screw (38) for prestressing one of the brackets (22).

Images