DE2358142A1 - FINISHING A METALLIC SEALING SKIN - IN PARTICULAR THE HOT LINER IN REACTOR PRESSURE VESSELS MADE OF REINFORCED CONCRETE - Google Patents

Description

FRIED »KRUPP GESELLSCHAFT LIMITED LIABILITY

in food

Completion of a metallic sealing skin - in particular the hot liners in reactor pressure vessels made of reinforced concrete

The invention relates to a termination of a metallic Sealing skin - especially the hot liner in reactor pressure vessels made of reinforced concrete with one arranged in the interior of the vessel Lid, the substantially cylindrical wall of the pressure vessel exposed to a hot fluid and optionally of the lid - seen in the direction of the temperature drop present in the part in question the hot liner, a thermal insulation and an adjoining second metal skin - the outer liner, on which a cooling system is attached.

Standard services for nuclear power plants, which are growing ever faster, are leaving the limits of steel usability today * manufactured pressure vessels - for example for water-cooled reactors - appear visible,

Feben the significant difficulties in manufacturing and When transporting large steel pressure vessels, the increased safety requirements must be mentioned, which the development Clay reactor pressure vessels made of prestressed concrete. This development is mainly based on the boiling water principle working nuclear reactors to observe which of the light water-cooled reactors have the largest container dimensions have, especially the largest inside diameter « "ET 127/73

^{J / He} 509823/0009

INSPECTED

2358K2

In the already developed prototypes of such reinforced concrete pressure vessels, the temperature sensitivity of the concrete - dehydration at temperatures above 100 ⁰ O, occurrence of thermal stresses in the wall - is taken into account by special thermal insulation systems.

One of these "well-known thermal insulation systems works on the principle of so-called" hot liners "d _o h _o of the first dense metal skin forming liner which is uncooled, is directly related to the present in the reactor pressure vessel fluid in contact ,, on the side opposite the fluid side the liner is followed by thermal insulation and this is followed by a second liner, which serves as formwork and carries cooling pipes on its outside (German Offenlegungsschrift 1 992 634).

As a result of the high temperature of the reactor fluid, significant constraining forces occur in the hot liner, as this - in the formal case designed as a cylinder - in can not expand freely in the radial direction.

A free expansion of the hot liner in the axial direction must be prevented, as the ^ BautdD-e - such as pipe penetrations, struts, supports bolts - the forces exerted would be too great. In addition, axial displacements of the hot liner could cause damage completion of the thermal insulation. Under certain circumstances, this would result in inadmissibly large deformations of the hot liner result.

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Prestressed concrete pressure tanks have already become known (German Offenlegungsschriften 1 759 374 and 1 784 625), in which an axial displacement of the inner wall of the container by a taper below the lid support should be avoided «,! The axial liner forces introduced into the concrete body via thrust

The disadvantage of this discharge is that by the taper reduces the usable container diameter will. The container must therefore be made larger in order to accommodate certain internals. Furthermore the usable container height is reduced by the sloping edge of the taper

Another principle of the axial fixation of an uncooled metallic sealing skin of a reactor pressure vessel is from the German Offenlegungsschrift 2 232 490 laäcanirto

The cover-side closure of the sealing skin is thereby of a Rotary body formed, which consists of a console adjoining the sealing skin, a "conical" attached to this Ring and an outer collar arranged above it consists. The ring, which has radial stiffening ribs Connected to the outer collar is over the heads of longitudinal tension members against the concrete body of the pressure vessel pressed

The disadvantage of this known liner closure can be seen in its large space requirement in the axial and radial direction. On the other hand, the bracket designed as a support element, which has a relatively large cross-section, is not thermally insulated from the inside of the container. There is therefore the risk that "inadmissibly high forced voltages occur in the console _o

509823/0009

The invention is based on the object of developing a liner termination whose axial and radial space requirements are small _o

The conclusion should be able to bear the weight of the lid absorb and the forces from the hindered thermal expansion, especially the hot liner in the cylindrical Transfer concrete body of the pressure vessel.

In addition, the termination should be designed so that it deformations - for example due to the specific Loading of the concrete body through pre-tensioning - can take up well and is largely protected against the creation of constrained tension in itself.

According to the invention, the problem posed is achieved in that the hot liner is in an upright position Schmiederring passes over, the lower end section of which, forming the extension of the hot liner, by a multiple is longer than the thickness of the hot liner and its cross-section increases towards the outside above the end section, wherein the forged ring is connected to the outer liner in the region of its largest cross section via a frustoconical sheet metal and its upper end section - whose cross section is in turn smaller than the cross section in the region of the truncated cone shaped sheet metal - at least a section of a cylindrical metal wall forms, and wherein the forged ring on its hot inside above the lower end section with undercut, in the direction of the temperature drop step-like rising paragraphs is provided, on which the lower end face each of an upright, cylindrical thin sheet is tightly attached.

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In the "undisturbed" area of the pressure vessel, the mainly caused by the action of heat Controlled stress states of the liner in that its circumferential expansion is limited by the cylindrical shape of the container and the bulging in this direction. Bolt is prevented.

At the upper end point of the liner there is also the need to absorb the constraining forces acting in the axial direction. For the liner, these forces are of the order of magnitude of the yield point. Since these forces - AES assumed to be constant wall temperature - specifically, the respective liner thickness is an important measure, which determines the size of these constraining forces.

In this respect, the forging ring serving as a conclusion must be regarded as a liner «, The axial forces are over the truncated sheet metal into the outer liner and passed into the concrete body of the pressure vessel

On the other hand, those occurring in the forging ring can be Stresses in the circumferential direction as a result of the present Do not simply reduce the dimensions to a permissible dimension. In particular, the bulging of the Forged ring cannot be controlled by bolts as in the rest of the liner industry, as these are also much stronger would have to be carried out and there would not be enough space for the introduction of forces into the concrete "

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The invention is therefore based on the idea that the forces occurring h a reduction of it causing cause, _e. the temperature, can be reduced. The forged ring forming the upper continuation of the hot inner liner is provided with thermal insulation on the side exposed to the hot fluid for this purpose - consisting of thin metal sheets arranged at a distance from one another.

Due to the higher thermal resistance of the thermal insulation will be the greatest temperature drop between the inner The surface of the thermal insulation and the concrete-side surface of the forged ring take place via this thermal insulation, so that the mean temperature of the ring will be significantly lower than that of the hot liner

The above-described dependency of the forced voltages of the liner thickness is taken into account that the forged ring - seen from below - starting with the same wall thickness as the liner only gradually plank? is (preferably at an angle of 60 °), namely depending on the gradually thicker thermal insulation.

Appropriately is on the outside of the forged ring - Above the truncated conical sheet, which the thermal insulation limited to the top - as well as a cooling device on the outside of the adjoining metal wall appropriate.

The forged ring as well as the upward if necessary the adjoining l & allwand is therefore directly on the concrete side chilled

609823/0009

In the embodiment of the subject matter of the invention is derSehmiedaing upkeep) of the upper end section with a multitude of distributed on its perimeter, provided cantilever arms protruding into the space filled by the fluid for receiving the weight of the lid.

On the container side, these cantilever arms, via which the weight is introduced into the pressure container, can also be designed as a ring . -; / \ . - _ - - -. "■" .-- '■ "..'■".

For thermal shielding of the upper end section of the forged ring and the adjoining metal wall is expediently a support ring on the cantilever arms - which is at the same time laterally at the upper end section of the forged ring is supported - placed on the with the lower end faces upright, cylindrical, thin sheet metal is tightly connected.

In a preferred embodiment of the subject matter of the invention there is a connection between the truncated cone shaped sheet metal and the outer liner on the container side from a support ring, which over on his Outside fastened bolts to the concrete body of the Pressure vessel is connected "

The frustoconical sheet preferably runs at an angle of about 90 ° to the outer edge rising outward above the lower end section of the forged ring;

The subject of the invention is described below using a Embodiment shown in the drawing in individual explained.

509 8237 0009

Show it:

1 shows a longitudinal section through a prestressed concrete pressure vessel in the area of the movable Deokels and

a longitudinal section, a prestressed concrete pressure vessel in the area of the liner termination, namely both the container-side and the lid-side liner closure

The inner wall 2 of the substantially cylindrical pressure vessel 1 made of prestressed concrete consists in the the cover 3 adjacent Besieh made of a tight metal lining 4 - the so-called hot liner -, a second metal wall 5 - the so-called outer liner ■ and a thermal insulation 6 "arranged between the two liners

Is there a cooling system on the outer liner 5? attached. Of the The hot liner 4 and the outer liner 5 are fixed to one another by means of round bolts (not shown) fastened in the concrete connectedο

The movable cover 3 is also with a side hot liner 8, to which a thermal insulation 9 adjoinsβ the wall 10 indicated schematically of the cover body forms the outer liner in the region of the hot liner 8 and the thermal insulation 9 at the same time.

S098237 # 0 "09

The internal pressure forces acting on the cover 3 are on the circumferential inclined surface 11 at the top Cover edge transferred to a pressure-resistant intermediate layer 1: 2, on which support plates 15 for the rest on two circles 14 arranged one below the other «, these are in swivel housings 15 axially displaceable held In the extended state, the ropes 14 are supported on each a thrust bearing 16 with a concave support surface. the Thrust bearings are connected to the concrete body of the pressure vessel 1 via support plates 17,

The sealing of the gap between the pusher and holder and the. movable cover 3, d »h. between the two hot liners 4 and 8 is made by means of an elastic. Material made torus 18 "■ This is on the lid side welded tightly to the upper continuation of the hot liner 8. The outboard side of the torus 18 is provided with a flange 19, which is on a formed from the extension of the hot liner 4 G-egenflache 20 is supported.

The for pressing the two conical surfaces 19 and 20 required Anp ^ ßkraft is through a variety generated by hydraulic presses 21, the pistons 22 of which are support on the flange 19 ,.

The hydraulic presses 21 are on their housing on the Side wall 23 of the pressure-resistant intermediate layer 12 attached.

509S23 / oil Sf

Like the pig. 2, the hot liner 4 goes into an upright forging ring 24, the lower end section 24 'of which, forming the extension of the hot male 4, is several times longer than the thickness of the hot liner 4' Length of section 24 * depends on the ratio of the maximum thickness of the Schmlederring 24 to the thickness of the hot liner 4? it is intended to reduce the stresses ₉ which are caused by the jump in stiffness of the successive cross-sections, _o

The cross section of the forged ring 24 widens, above the lower end portion 24 * on the outside at a certain angle, whereby a inclined wall 24 "is created"

The angle formed by the outer wall of the section 24 ^l and the wall 24 ^lf depends on the magnitude of the forces acting in the axial direction in the hot liner 4, which during the heating or cooling of the between the hot liners 4 and 8 existing fluid act on the cross section of the lower end section 24 ^f '»

The forged ring 24 is in the region of its largest cross section About a frustoconical plate 25 and one The support ring 26 is connected to the outer liner 5 Round bolt 27 held in the concrete body of the Druok container 1

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Above the connection point of the forged ring 24 with the support ring 25, the cross section of the part 24 decreases again and merges into the upper end section 24 " ^T. This is connected to a cylindrical metal wall 28, which forms the continuation of the hot liner 4. The cylindrical metal wall 28 is in turn connected to the counter surface 20 »

The forged ring 24 is provided on its hot inside above the lower end section 24 ^f with back-turned, in the direction of * the temperature drop, incrementally rising "shoulders 29, on which the lower end face of an upright, cylindrical thin sheet 30 made of corrosion-resistant material di · ⁰ ^ The outer edge of the lowermost shoulder and the sheet metal 30 associated therewith lie in alignment with the side of the hot liner 4o facing the hot fluid

This recessed arrangement of the thermal insulation of the forged ring 24, the lowering of the movable Cover 3 facilitated, below the upper end section 24 "* is the forged ring with cams 31 provided, which in the gap between the liners and 8 protrude. The cams 31 take on the weight of the cover 3, which is attached to! "Ratzen 32"

A support ring 33 is arranged above the cam 31, which with the lower end faces upright, cylindrical, thin metal sheet 34 is tightly connected. The innermost of the sheets 34 is in alignment with the corresponding sheet 30,

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Because of the increased thermal resistance through the heat transfer from the fluid to the first sheet 30 _o 54, the heat transfer from the first sheet or to the top between this and the subsequent sheet fluid, etc. builds the! Temperature of the fluid to the surface of the forged ring 24 significantly from , whereby the desired drop in temperature in the cross section of the forged ring is achieved _o

That, for example, from steam. A temperature of 286 ⁰ O and a pressure of 71 ata (lying on the dotted line of water) will condense in the gaps between the individual sheets 30 and 34 due to the lower surface temperature of the sheets to form water between the individual sheets consequently a vertical layer of water, to prevent the water layers from running off, the lower end faces of the metal sheets 30 and 34 are tightly connected to the part carrying them.

The equipment of the forged ring 24 with a large number of individual cams 31 instead of a continuous support ring has the advantage that the additional heat flowing into the cross section of the forged ring 24 is within limits is held "

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In addition, the spaces between the cams allow the passage of parts which protrude beyond the diameter circumscribed by the claws, for example the bolt 36 of the cover guide _{e, supported on a spring assembly 35 ^ and movable transversely to the longitudinal axis of the cover}

The arrangement of the cams 31 on the forged ring 24 has the advantage that a location has been selected to accommodate the weight of the lid, which is already one for the absorption of individual forces has a favorable structure, namely a "reinforcement; for the function "Taking up the lid's own weight" therefore does not need any further, possibly costly, point of discontinuity to be created «,

Just like the outer liner 5, the forged ring is above the connection point with the sheet metal 25 and the metal wall 28 that adjoins it towards the bottom provided with a cooling device 37 on its outside.

The hot liner 4 are located below the support ring 26 and the outer liner 5 firmly connected to one another via a multiplicity of struts 38. As is well known, these have the task of forces from the hot liner 4 into the concrete to transfer the body of the pressure vessel 1 «,

The upper end of the hot liner 8 of the lid corresponds to the end of the described in detail container-side liners 4.

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The liner termination is also formed by a forged ring 39, which is shaped over a truncated alloy Sheet 40 is supported on the outer liner 10. A cooling device 41 is attached to this.

The thermal insulation of the forged ring 39 is carried out by means of corrosive-resistant sheets arranged in steps 42 and above the cantilever arm 39 * over metal sheets 44o fastened in a drag ring 43, the latter at its upper end into a bearing ring 45, which is supported on the plan 19 of the torus 18 »

The gap between the upper end of the sheets 34 and that of the sheets 44 is provided by an elastic Ring 46 closed, which was supported on a conical surface belonging to the innermost ring 34

The described execution of the axial liner closure It can of course also be used in other places - where the hot liner ends. for example when connecting pipe ends which penetrate the concrete body of the pressure vessel 1 and hit the hot liner on the tank side,

509823/0009

Claims (1)

A η s ρ r ü ehe Completion of a metallic sealing skin - in particular the hot liner in reactor pressure vessels made of reinforced concrete with a cover arranged in the interior of the vessel, the essentially cylindrical wall of the pressure vessel and, if applicable, of the cover exposed to a hot fluid - in each case viewed in the direction of the temperature drop present in the relevant part - consists of .the hot liner, thermal insulation and an adjoining second metal skin - the outer liner - on which a cooling system is attached, / characterized in that the hot liner (4, 8) is in an upright forged ring (24 , 59) whose lower end section, which forms the extension of the hot liner, is several times longer than the thickness of the hot liner (4,8) and whose cross section increases outwards above the Ehdab section, the forged ring (24,39) in the area of its largest cross-section over a frustoconical sheet metal (25, 40) with the Au ßen-Liner (5,10) is connected and its upper end section - the cross section of which is in turn smaller than that (cross section in the area of the frustoconical sheet (25,40) - forms at least a section of a cylindrical metal wall, and the forged ring (24, 39) is provided on its hot inside above the lower end section with back-turned shoulders that rise in steps in the direction of the temperature drop, on which the lower end face of an upright, cylindrical thin sheet (30, 42) is tightly fastened ₀ -15- 5 09 & 23/0 0 09 Closure according to claim 1, characterized in that on the outside of the forged ring (24, 39) - above the frustoconical sheet (25, 40) which limits the thermal insulation (6, 9) upwards - and on the outside of the adjoining Metal wall (28) a cooling device (37) is attached ₀ 3ο closure according to claim 1 and / or 2, characterized in that that the forged ring (24,39) with a plurality of distributed on its circumference, in the from Fluid-filled space protruding cantilever arms (31,39 *) is provided to accommodate the weight of the lid. 4a termination according to claim 3, characterized in that on the cantilever arms (31,39 *) a support ring (33,43) - which is at the same time laterally on the upper end portion of the Forged rings (24,39) supported - is put on, the upright, cylindrical, cylindrical, thin sheets (34,44) is tightly connected. 5. Closing according to one or more of the preceding Claims, characterized in that on the container side the connection between the frustoconical sheet metal (25) and the outer liner (5) consists of a support ring (26) which is attached to bolts (27) on its outside. is connected to the concrete body of the pressure vessel (1). 6. Termination according to one or more of the preceding claims, characterized in that the frustoconical Sheet metal (25, 40) at an angle of approximately 90 ° to that rising outward above the lower end section Outer edge of the forged ring (24,39) runs. 5 O 9 8 2 3/0 "0 • ff. L e r s e i t e