RU2690158C1 - Transport locker of safety system of nuclear power plant - Google Patents

Abstract

FIELD: machine building.SUBSTANCE: invention relates to atomic engineering. Transporting gateway of localizing safety system of nuclear power plant includes cylindrical housing, in flanges of which there are made transport openings. Each of openings is equipped with elliptical cover with locking mechanisms of cover clamping. Locking mechanism is made in the form of a bayonet lock, and consists of an elliptical cover, ledges interacting with grooves made along the inner diameter of the bayonet rotary ring. Bayonet ring is installed on housing flange. Each bayonet ring is equipped with centering devices installed along its circumference, interacting with housing flange by means of rollers located on axis of centering device. Each rotation mechanism comprises a drive. Cooling channels are made in flanges of cover and housing. To open gateway opening covers are equipped with diametrically installed rollers resting on brackets of recoil frame. Clamping mechanisms are fixed on the cover for compression of seal of bayonet lock. Each clamping mechanism comprises a drive connecting the lid and the sliding frame to move the lid along the housing axis.EFFECT: invention makes it possible to provide air-tightness of gate apertures.1 cl, 6 dwg

Description

The invention relates to nuclear engineering, in particular to equipment installed in the protective shells of a nuclear reactor, providing a tight overlap of the transport openings localizing the security system of a working nuclear power plant (NPP) and serving for the transportation of heavy and bulky cargo.

The transport sluice (hereinafter referred to as the sluice) is an element of the hermetic fencing system, which is part of the localizing NPP safety system in the reactor containment, ensuring safe operation of the NPP and hermetic shutdown of the transport opening for transporting heavy and large cargoes through the sluice when the reactor is operating.

The gateway is used to perform the following functions:

- preservation of the design tightness of protective shells under normal operating conditions and emergency situations;

- protection from external influences of the environment of systems and components, the failure of which can lead to the release of radioactive substances;

- ensuring transportation through the gateway with preservation of the tightness of the system of hermetic fencing of various cargoes: fresh fuel in covers, spent fuel in containers, radioactive waste in containers, transport and technological equipment.

Known transport gate localizing the security system of a nuclear power plant, containing a cylindrical body, in the flanges of which transport openings are made, each transport opening is provided with a sealing sheet with mechanisms for clamping it to the flanges of the transport opening and sealing located between them in the form of a sealing gasket, opposite each sealing sheet is installed Sliding frame moving along guides with the ability to move sealing sheets when opening / closing gateways transport openings, studs are screwed into the flanges of the gateway transport opening, which are aligned with the corresponding holes along the edges of the sealing sheets when closing the gateways transport openings (patent RU №2564512 С2, MGT G21F 7/005, priority 13.12.2013, publ. 10.10.2015 Patent RU No. 140342 U1, IPC G21F 7/005, priority of December 13, 2013, published on May 10, 2014).

However, to ensure the normal operation of the transport gateway and reliable sealing of the interfaces, it is necessary to technically difficult for significant dimensions and weight of sealing sheets, and fine-tuning the mechanisms for moving and fixing the position of the sliding frames with sealing sheets, relative to the location of the studs, ensure that the nuts are mechanically screwed on coaxially located studs. If it is necessary to transport large-size cargoes and NPP equipment with a gateway that exceeds the dimensions of transport openings, for example, steam generators, which are covered by sealing sheets, it is necessary to disconnect both flanges from the body, which leads to a leakage of the reactor compartment. In this case, the detachment of the flanges is a long and costly operation. Such work on the opening / closing of transport openings of the gateway requires the mandatory shutdown of the reactor and, accordingly, the shutdown of the operation of the entire NPP. When there is a misaligned and / or inaccurate positioning of the nuts in the sealing mechanisms on the sealing canals relative to the studs on the flanges of the transport opening or when the studs are not perpendicular to the sealing plane, it becomes difficult and sometimes impossible to screw the nuts on the studs without damaging them to ensure the required tight tight pressure on the sealing sheets to the flanges transport opening, that is, possible mechanical damage to threaded connections and violations of the required sealing yazheniya. In case of a possible emergency situation, namely de-energizing the electric drives of the gateway sealing mechanisms, sealing the transport opening of a gateway of known construction using manual duplicated sealing mechanism drives takes considerable time, on the order of several hours, to seal the transport opening from either side. And this is on condition that the removable flange is in its proper place, and not dismantled or completely cut off. The design of the flanges of the transport openings is not equal due to the fact that equivalent elements of the seal, such as fasteners, sealing rings are located at different distances from the axis of the lock body. Known technical solutions when changing temperature and pressure will not provide the same movement of the sealing surfaces of the flange and sealing cloths and as a result - loss of tightness of the transport opening of the gateway. Seals of the gateway transport opening are not protected from possible direct exposure to environmental factors such as fever, decontamination solutions, steam, open fire, etc. Bolted connections of removable flanges complicate the design, reduce the reliability, tightness and durability of the gateway design.

One of the working conditions of the sluice at NPPs is to ensure the performance of the structure at temperatures above 100 ° C. The design of the known gateway does not protect the seal from excessive overheating, which reduces the life and reliability of the seal assembly and seals the transport opening when exposed to high temperatures.

The closest technical solution, selected as a prototype, is a gateway transport localizing the safety system of a nuclear power plant, containing a cylindrical body installed in the protective shells of a nuclear reactor, in the flanges of which transport openings are made, each of which is provided with a sealing elliptical lid with a locking mechanism for clamping the lid to flanges of the transport opening of the housing and the seal located between them, with the locking mechanism on each side of the gateway opening made in the form of a bayonet lock consisting of an elliptical crown ring shaped as an outer diameter in the form of projections interacting with a ring cog in the form of depressions along the internal diameter of a bayonet rotary ring mounted on the housing flange by axial movement of the cover and the occurrence of the cover protrusions into the cavity of the bayonet rings with the subsequent closure of the bayonet lock by the angular displacement of the bayonet ring relative to the body (patent No. 180665 U1, IPC G21F 7/005, priority from 01/17/2018, publ. 06/20/2018).

The disadvantage of the known gateway is that the gateway design does not ensure the normal concentric position of the bayonet ring when it rotates relative to the housing flange due to the absence of centering devices in the bayonet lock required to prevent the bayonet ring from moving relative to the housing flange due to gravity them, as well as reducing significant sliding friction forces between the bayonet ring and the gateway body flange company of a bayonet lock ring, as the bayonet ring at the top point under the action of gravity touches the flange of the case. This disadvantage can lead to the loss of operability by the gateway as a result of the jamming of the bayonet lock and, as a result, the gateway loses tightness. In addition, the tightness of the seal assembly of the bayonet lock of the gateway must be guaranteed, and the seal assembly of the bayonet lock is especially reliable. The design of the bayonet lock of a known gateway does not protect the seal from excessive overheating, which reduces the life and reliability of the seal assembly, as well as sealing the transport opening when exposed to high temperatures, because One of the conditions of the gateway operation at NPPs is to ensure the design operability at temperatures above 100 ° C. At the same time, the tightness of the well-known gateway is ensured by a dual-circuit rubber seal located in the grooves at the end of the body along the entire perimeter of the opening, pulled out by means of excessive pressure of the working fluid (liquid, gas). In this case, the sealing of the gateway directly depends on the strength and reliability of the pressure source pipelines, which is unacceptable, since with a slight leakage of the working environment, the tightness of the seal assembly will be impaired.

An object of the invention is to provide guaranteed tightness of the transport openings of the gateway, improving the reliability, operability of the bayonet lock and the protection of seal assemblies from the effects of elevated temperature.

The technical goal is achieved by the fact that the sluice transport localizing the security system of a nuclear power plant, containing a cylindrical body installed in the protective shells of a nuclear reactor, the flanges of which have transport openings, each of which is equipped with a sealing elliptical lid with a locking mechanism for pressing the cover to the flanges of the body opening and seals located between them, with the locking mechanism on each side of the opening made in the form of a bayonet lock ra, consisting of an elliptical cap made by the outer diameter in the form of protrusions interacting with the ring gear in the form of depressions on the inner diameter of the bayonet rotary ring mounted on the housing flange by axial movement of the cap and the occurrence of the cap protrusions in the depression of the bayonet ring with subsequent closure bayonet lock by angular displacement of the bayonet ring relative to the housing, according to the invention, each bayonet ring is provided with centering devices, mouth along its circumference, interacting by means of rollers with the flange of the body, and turning mechanisms, each of which contains an actuator installed and interconnecting the body and the bayonet ring, in the flanges of the cover and the body there are cooling channels with liquid capable of protecting the seal from excessive overheating, each cover is provided with diametrically mounted rollers resting on the brackets of the recoil frame, ensuring its rectilinear movement, on which the mechanism is additionally fixed A clamp to move the cover along the axis of the gateway and crimp the seal of the bayonet lock, with each clamping mechanism containing an actuator connecting the cover and the frame to a retractable one.

The use of centering devices installed along the diameter of each bayonet ring, interacting by means of rollers with the housing flange, and rotation mechanisms, each of which contains an actuator mounted and interconnecting the housing and the bayonet ring, prevents the bayonet ring from shifting from its normal concentric position when rotating it relative to the flange of the case, reduces the forces of sliding friction between the bayonet ring and the flange of the case, which arise when the bayonet ring is rotated relative to gateway housing. This solution allows avoiding jamming of the bayonet ring when turning it relative to the housing flange, as a result of which the reliability of the bayonet lock is increased, and the reliability of the sealing of the transport opening of the gateway accordingly increases.

The implementation in the flanges of the lid and the housing of the cooling channels with liquid provides the possibility of protecting the seal from excessive overheating, which contributes to increasing the service life of the seal, increasing its reliability, thereby sealing the transport opening of the gateway when exposed to high temperatures, as one of the conditions of the gateway’s operation NPP is to ensure the performance of the design at temperatures over 100 ° C.

The supply of covers with diametrically mounted rollers, with the help of which the covers rest on the brackets fixed on the sliding frame, ensures the straight movement of the cover along the gateway axis.

The frame is retractable, moving along the guides of the frame fixed, provides the possibility of opening / closing the transport opening of the gateway.

Fastening the clamping mechanisms on the lid, each of which contains a drive connecting the lid and the frame to the retractable frame, provides a mechanized compression of the bayonet seal seal by moving the lid along the gateway axis along the entire perimeter of the transport opening, enhancing the reliability, Bayonet shutter performance.

In the design of the transport gateway shown in FIG. 1-6, includes the following elements:

1 - body

2 - cover

3 - elliptical bottom of the cover

4 - cover flange

5 - housing flange

6 - seal on the surface of the flange cover

7 - cooling channels with liquid on the flanges of the housing and cover

8 - bayonet ring on the housing flange

9 - grooves on the inner diameter of the bayonet ring

10 - protrusions on the outer diameter of the cover

11 - centering devices on the bayonet ring

12 - centering roller

13 - axis of the centering device

14 - fixed frame

15 - recoil frame

16 - brackets on the retractable frame

17 - rollers on the cover

18 - mechanisms for clamping the cover

19 - mechanisms of rotation of the bayonet ring

20 - bracket on the body

21 - bayonet ring bracket

The proposed design of a gateway for a transport localized safety system of a nuclear power plant is illustrated by drawings, where:

in fig. 1 shows a gateway comprising a housing 1, along the ends of which there are covers 2 with clamping mechanisms 18 of covers 2 mounted on them, sliding frames 15, fixed frames 14, longitudinal section;

in fig. 2 shows the detail I in FIG. 1, containing gateway elements, sealing the transport opening, namely: cover 2 with elliptical bottom 3, lid clamping mechanism 18, bayonet ring 8, housing flange 5, cover flange 4 2, roller 2 of the cover 2, resting on the frame bracket 16 retractable 15, having the ability to move in the guide frame of the fixed 14;

in fig. 3 shows the external element II in FIG. 1, comprising a flange 5 of the housing 1, a flange 4 of the cover 2, a bayonet ring 8, a centering device 11 on the bayonet ring 8, a roller 12 of the centering device, an axis 13 of the centering device, a seal 6 on the sealing surface of the flange 4 covers 2, the compression of which provides sealing of the transport opening of the gateway, cooling channels 7 with liquid on flanges 4 and 5 of cover 2 and housing 1, projections 10 of cover 2;

in fig. 4 is a view III in FIG. 1 from the side of the hermetic zone (GZ), the cover 2 and the recoil frame 15 are shown, interconnected by the mechanisms of the clamp 18 of the cover 2, the frame is fixed 14, the bayonet ring 8 on the flange of the housing 1, the turning mechanisms 19 of the bayonet ring 8, side view;

in fig. 5 shows the detail IV in FIG. 4, comprising grooves 9 of the bayonet ring 8, the body 1, to which the rotation mechanism 19 of the bayonet ring 8 is attached using brackets 20 and 21;

in fig. 6 shows a section V in FIG. 4, comprising a cover 2, a recoil frame 15, and a clamping mechanism 18 of the cover 2 interconnecting them.

The sluice transport localizing safety system of a nuclear power plant is an isolated cylindrical body 1 with two hermetically closed transport apertures with covers 2 separating two zones of the nuclear power plant — a hermetic zone (GZ) and a non-tight zone (NGZ). One cover 2 of the gateway leads to the GZ, the other - to the NGD (Fig. 1). Each of the covers 2 consists of an elliptical bottom 3 and a flange 4 (Fig. 2). The flanges 5 are made on the end surface of the housing 1. To ensure the sealing of the transport opening of the airlock, the contact surfaces of the flange 5 of the housing 1 and the flange 4 of the cover 2 are in the form of a circle and are sealing. On the sealing surface of the flange 4 of the cover 2 in the groove is located the seal 6 of the bayonet lock (Fig. 3). The design of the housing 1 and the covers 2 is made of equal strength, i.e. when the temperature and pressure change, the deformations and displacements of the sealing surfaces of the housing 1 and the covers 2 are comparable, damage to the seal 6 is eliminated, which ensures sealing of the transport opening of the gateway under any operating conditions, including emergency ones.

Protection of the seal 6 against excessive overheating is provided by the cooling channels 7, made in the flange 4 of the cover 2 and the flange 5 of the housing 1 (Fig. 3). The channels 7 are filled with fluid circulating through them at the expense of the pump. The cooling system allows you to protect the seal 6 from excessive overheating, which contributes to increasing the life and increasing its reliability, as well as sealing the transport opening when exposed to high temperatures, since one of the conditions for the gateway operation at nuclear power plants is to ensure that the structure works at temperatures over 100 ° C. Also, the seal 6 is protected with a bayonet ring 8 on the flange 5 of the housing 1 from possible direct exposure to environmental factors such as elevated temperature, deactivating solutions, sources of ionizing radiation, etc.

Sealing the transport opening is provided by a locking mechanism on each side of the gateway opening, made in the form of a bayonet lock. The bayonet closure consists of an elliptical cover 2 with an outer diameter of a ring gear in the form of projections 10 interacting with a ring gear in the form of grooves 9 along the internal diameter of a bayonet rotary ring 8 mounted on the flange 5 of the housing 1 (Fig. 3, 5). The bayonet ring 8 is provided with centering devices 11, mounted around the circumference of the bayonet ring 8, which includes a roller 12 located on the axis 13 of the device 11. The rollers 12 of the centering devices 11 interact with the flange 5 of the housing 1 by contact with the flange 5 of the housing 1 and serve protection of the displacement of the bayonet ring 8 from the normal concentric position during its rotation, as well as to reduce the sliding friction forces (Fig. 3).

To open the transport opening on each side of the airlock, a fixed frame 14 is installed. A fixed frame 15 is installed in the fixed frame 14 (fig. 1, 4). The recoil frame 15 moves along the frame guides of the fixed 14 in the direction perpendicular to the axis of the body 1 of the gateway. To open the gateway opening on each cover 2, two rollers 17 are diametrically mounted. The rollers 17 rest on the brackets 16 fixed on the recoil 15 frame (Fig. 2). The cover 2 is fixed clamping mechanisms 18, each of which contains a drive mechanically interconnecting the cover 2 and the frame recoil 15. The pressing mechanisms 18 move the cover 2 along the axis of the housing 1 gateway until the projections 10 of the cover 2 into the corresponding grooves 9 of the bayonet ring 8 , providing a seal of the transport opening by crimping the seal 6 (Fig. 4-6).

On both sides of the bayonet ring 8, rotation mechanisms 19 are installed for the subsequent mechanized closure of the bayonet lock by angular displacement of the bayonet ring 8 relative to housing 1 (Fig. 4, 5). The rotation mechanisms 19 of the bayonet ring 8 connect the housing 1 and the bayonet ring 8 with two brackets 20 mounted on the housing 1 and two brackets 21 mounted on the bayonet ring 8 (Fig. 5).

The transport gateway works as follows.

The modern gateway of the nuclear power plant localizing safety system, which provides transportation of large-sized cargo to the central hall of the reactor section of the nuclear power plant, is a cylindrical chamber with a length of more than ten meters and a diameter of more than seven meters, hermetically locked from both sides with lids. The covers are opened alternately with the help of an automated control system, ensuring tightness when moving goods between the hermetic and unpressurized areas of the nuclear power plant. When carrying out planned work or replacing nuclear fuel at a nuclear power plant, the design of the gateway protects the plant personnel and the environment from radioactive impact without disturbing the reactor tightness branches without stopping the reactor.

Starting position: the gateway is sealed, the elliptical covers 2 on the NGZ and GZ side are in their regular place in the transport opening, ensuring its sealing, the recoil 15 frames are opposite the covers 2 and are mechanically connected with them using clamp mechanisms 18, while the rollers 17 of the covers 2 are supported on the brackets 16 of the sliding frames 15, the seal 6 on the lid 2 is compressed, the bayonet lock is in the “closed” position, the cooling channels 7 are filled with fluid circulating through them through the pump.

For transportation through the gateway of goods or equipment, for example from NGZ to GZ (Fig. 1), the depressurization of the transport opening of the gateway from the NGZ side is carried out. The bayonet ring 8 is rotated to the “open” position by means of rotation mechanisms 19 and centering devices 11. At that, roller 12 located on axis 13 of centering device is in contact with flange 5 of housing 1. Centering devices 11 rotate together with bayonet ring 8, ensuring the normal concentric position of the bayonet ring 8 relative to the flange 5 of the housing 1, as well as the reduction of the sliding friction forces between them. When the bayonet ring 8 reaches the “open” position, the circulation of fluid in the cooling channels 7 on the flanges 5 and 4 of the housing 1 and the cover 2 stops. The liquid in the cooling channels 7 remains. Next, remove the protrusions 10 of the cover 2 from the grooves 9 of the bayonet ring 8 using the mechanisms of the clamp 18 of the cover 2 and the rollers 17 on the cover 2, resting on the brackets 16 of the recoil frame 15. The cover 2 is moved along the axis of the gateway housing 1 to the recoil 15 frame by the amount of working stroke mechanisms of the clamp 18 of the cover 2, while the seal 6 takes the original form. Next, the recoil frame 15 is moved, together with the lid 2, mechanically connected with it, along the frame guides fixed 14 in the direction perpendicular to the axis of the gateway body 1 by the amount of the frame stroke of the recoil frame 15. The transport opening is open from the NGZ for transportation of cargo.

Then, when moving the trolley with the transported cargo to the lock, they provide sealing of the transport opening of the lock from the side of NGZ. To do this, move the frame recoil 15 together with the lid 2, mechanically connected with it, fixed 14 along the frame guides in the direction perpendicular to the axis of the gateway body 1 (Fig. 4) to the transport aperture by the amount of the working stroke of the recoil 15 until the projections 10 on the outer diameter of the cover 2 with the grooves 9 of the bayonet ring 8. Then, the projections 10 of the cover 2 are inserted into the grooves 9 of the bayonet ring 8 using the mechanisms of the clamp 18 of the cover 2 and the rollers 17 supported on the brackets 16 of the recoil frame 15. The cover 2 is moved along the axis of the housing 1 of the gateway from the frame retractable 15 for the magnitude of the working stroke of the mechanisms of the clamp 18 of the cover 2 to compress the seal 6 (Fig. 2-4). Seal 6 provides sealing of the transport opening by crimping.

Then the bayonet ring 8 is turned to the “closed” position by means of the rotation mechanisms 19 of the bayonet ring 8 and centering devices 11. The centering devices 11 rotate together with the bayonet ring 8, ensuring the normal concentric position of the bayonet ring 8 relative to the flange 5 of the housing 1, as well as reducing forces sliding friction between them. When the bayonet ring 8 reaches the “closed” position, the circulation of the liquid in the cooling channels 7 to the flange 5 of the housing 1 and the flange 4 of the cover 2 begins.

Then carry out depressurization of the transport opening of the lock from the side of the GZ. To do this, turn the bayonet ring 8 to the “open” position using the rotation mechanisms 19 of the bayonet ring 8 and centering devices 11. The centering devices 11 rotate together with the bayonet ring 8, ensuring the normal concentric position of the bayonet ring 8 relative to the flange 5 of the housing 1, as well as reducing sliding friction forces between them. When this circulation of fluid in the cooling channels 7 on the flange 5 of the housing 1 and the flange 4 of the cover 2 stops. The liquid in the cooling channels 7 remains.

Remove the protrusions 10 of the cover 2 from the grooves 9 of the bayonet ring 8 using the mechanisms of the clamp 18 of the cover 2 and the rollers 17 resting on the frame brackets 16 of the recoil 15. The cover 2 is moved along the axis of the housing 1 to the frame of the recoil 15 by the amount of working stroke of the clamping mechanisms 18 of the cover 2 , while the seal 6 takes the original form (Fig. 4).

Next move the frame recoil 15 together with the cover 2, mechanically connected with it, along the frame guides fixed 14, in the direction perpendicular to the axis of the housing 1 by the amount of the working stroke of the frame recoil 15. The transport opening from the GB side is open for transportation of goods. The cart with the transported cargo is moved to GZ.

Next, carry out the sealing of the transport opening of the gateway from the GZ. Sliding frame 15 is moved together with cover 2 mechanically connected with it by fixed frame 14 guides the frame in the direction perpendicular to the axis of body 1 in the opposite direction to the transport aperture by the amount of working frame of rollback 15 until the projections 10 on the outer diameter of the cover 2 coincide with grooves 9 bayonet ring 8. Insert the projections 10 of the cover 2 into the grooves 9 of the bayonet ring 8 using the mechanisms of the clamp 18 of the cover 2 and the rollers 17 supported on the brackets 16 of the recoil frame 15. The cover 2 moves along the axis of the housing 1 of the gateway from the recoil frame 15 and the value of stroke clamp the lid 18 compression mechanism 2 to seal 6. The seal 6 ensures sealing of the opening by crimping vehicle. Then the bayonet ring 8 is turned to the “closed” position by means of the rotation mechanisms 19 of the bayonet ring 8 and centering devices 11. The centering devices 11 rotate together with the bayonet ring 8, ensuring the normal concentric position of the bayonet ring 8 relative to the flange 5 of the housing 1, as well as reducing forces sliding friction between them. When the bayonet ring 8 reaches the “closed” position, the circulation of the liquid in the cooling channels 7 to the flange 5 of the housing 1 and the flange 4 of the cover 2 begins.

Thus, the use of the proposed design of the sluice of a localized security system of a nuclear power plant with a bayonet lock reduces the time required to transport bulky goods and equipment, as well as seal the sluice transport passage in a shorter time, increase reliability and protect the seal assemblies from the effects of elevated temperature.

Claims (1)

Gateway transport localizing safety system of a nuclear power plant, containing a cylindrical body installed in protective shells of a nuclear reactor, in the flanges of which are made transport openings, each of which is equipped with an elliptical sealing lid with a locking mechanism for clamping the cover to the flanges of the transport aperture of the housing and the seal located between them, at the same time, the locking mechanism on each side of the aperture is made in the form of a bayonet lock, consisting of an e an elliptical gear ring in the form of protrusions interacting with a ring gear in the form of depressions along the internal diameter of a bayonet swivel ring mounted on the housing flange by axially moving the cover and entering the lid protrusions into the bayonet ring hollow with subsequent closing of the bayonet gate by angular displacement of the bayonet ring relative to housing, characterized in that each bayonet ring is provided with centering devices mounted around its circumference, interacting with rollers with a housing flange, and rotation mechanisms, each of which contains a drive, mounted and interconnecting housing and bayonet ring, cooling channels with liquid are made in the flanges of the cover and housing, with the possibility of protecting the seal from excessive overheating, each cover is provided with diametrically mounted rollers resting on the brackets of the recoil frame, ensuring its rectilinear movement, on which clamping mechanisms are additionally fixed for moving the cover along the gateway axis and ment sealing bayonet, with each clamping mechanism comprises an actuator interconnecting the cover and the sliding frame.

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