DE2211190A1 - Sodium-heated superheater - Google Patents

Description

Sodium-heated superheater

The invention relates to "a sodium heated superheater.

When steam is overheated in nuclear power plants, the risk of a sodium-water reaction and the associated extensive damage must be reduced as far as possible by using a system that works safely and reliably and is accessible for testing and / or repair purposes. Equipped with insertion systems are known in which water vapor in one direction through the interior of two coaxially arranged one inside the tubes and then .in the opposite direction between these two pipes passing * ströat * In view of the large temperature difference between the two inside and outside the Innenrohrea flowing water , it is necessary to insulate the inner pipe.This results in a somewhat inexpedient, complicated structure *

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Another possibility arises in the case of nuclear power plants with a sodium-cooled reactor by superheating the water vapor Coiled tube or helical tube superheater used. However, most of these coiled tube superheaters also occur several difficulties. For example, the coils must be protected against vibrations and it is often difficult to have the necessary facilities for quick and safe drainage of the pipe failure occurring sodium-water reaction products.

It is to overcome an important object of the invention, these and other disadvantages of the prior art and to provide a simple means economically produced, powerful superheater else meets the demands made in a particularly reliable V /, has a minimum of ^v space and is equipped with a device for the safe removal of the products of an accidental sodium-water reaction.

The invention proposes a superheater in which more saturated Water vapor is supplied via downpipes, which are arranged between an escape channel and an insulating, coaxial \ Rohrbunde1-Stutzmantel extend downwards. The water vapor then flows upwards through helical tubes from _. downward flowing liquid sodium washes around and thus warmed will. The tube coils or helical tubes are on the Escape channel in a coaxial arrangement surrounding the supporting jacket helically upwards.

A superheater of the type mentioned is characterized according to the invention in that an elongated one is perpendicular

8iigeord110ter pressure vessel one inlet; _. .1

for liquid aetrium and near its bottom part / a sodium outlet having in and coaxial with the pressure vessel

2 0 9 8 3 9/0831 ORIGINAL INSPECTED

a Rohrbimdcl support jacket is arranged, in which a coaxially aligned escape channel for Katriura water reaction products is provided that a number of downpipes extends down into an area under the support jacket and the Entv.-eichkana.ls between these extends, each of which is connected by means of a connecting tube to a helical tube guided upwards between the support jacket and the pressure vessel, so that saturated water vapor can be guided down through the connecting tubes through the connecting tubes and back up in the V'endel tubes so that it can be guided by means of is superheatable via the inlet downward flowing liquid sodium flowing around the helical tubes, and that the space between the escape channel and the support jacket is filled with sodium, the level of the sodium-liquid Xüi.lung being below the upper end of the escape channel.

• Further features, details and advantages of the invention result from the following description of an embodiment with reference to the drawing, which is a front view, partially shows in section, a superheater according to the invention.

A coiled tube superheater designated in its entirety by 10 comprises a cylindrical pressure vessel 12, the main vessel 14 and vessel lid 16 of which are essentially one have circular horizontal cross-sectional area. The '16 container lid is provided with a lower annular flange 18 at the top of one in the "top" of the main tank provided annular flange 20 attached. The container lid has an inlet ring chamber 24, which via inlets 26 Steam can be supplied. The inlet ring chamber 24 is delimited by a vertical outer wall 28, a vertical one Inner wall 30 and an annular plate 32, which in its peripheral area is bolted to upper portions of the vertical walls 28 and 30.

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From the inlet ring chamber 24 the water vapor flows over ' Downpipes 36, which are guided in a tube bundle support jacket 38. In order to be able to accommodate all downpipes 36 is the tube bundle support jacket 38 in the region of an upper section .40 extended.

The downpipes 36 are arranged in an annular space, which is formed between the tube bundle support jacket and one provided in this in a coaxial arrangement central escape anal 42. The task of this central resp. centrally arranged.Entnahmkanalρ 42 is below with further details explained.

The downcomers 36 extend downwardly over the tube bundle support jacket 38 and the central soft canal. 42 out through an annular plate 44 and are each connected to a connecting pipe 46. These lead to the outside world and push through the ring plate 44 back xmd upwards furthermore a perforated ring plate 48 and one of the side supports serving lower perforated ring plate 50. Jedos of the connecting pipes 46 connects to a helical tube 52, of which only a few are shown for reasons of clarity and which serve to guide the water vapor upwards into an area which is only slightly below distributor rings 54 whose task is explained in more detail below. The helical tubes 52 are at their upper ends with upwards extending riser pipes 56 connected, which lead to an annular tube plate 60, which from the Rohrbündelr-StütE-inantel 38 protrudes outwards. After leaving the risers 56 the water vapor reaches parts of the tube plate 60 covering Collection chambers 62 for wasperdar bowl outlets '64.

The steam is overheated in the v / end pipes 52 by means of the liquid sodium flowing downwards. ITatriua is fed to the superheater 10 via disodium inlets 68 ". from there it arrives in the ring chamber, in which it is straight Riser pipes 56 between the distributor ring 54 and Beruh! Gungnlizv /. Diimpferring 70 r.nceox'dncjt in. Distribute the rings f> 4

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the sodium evenly downwards over the "straight" tubes (56). The sodium then washes around the helical tubes 52 and passes through the lower perforated ring support plate 50 and the ring plate 48 in the area above the ring plate 44. It then flows through the in the middle worked out. recess from and arrives through an opening 7 ^ in a base plate 76 to the sodium outlet 80, from where it is fed to the reactor for reheating. ■

The tube coils or helical tubes .52 are connected by means of a Bracket 81 supported, which is "made up of" a "tube bundle support frame 38 enclosing collar and a number in radial direction extending beams composed, which are connected to the riser pipes 56. Any porter supports a number of riser pipes and thus also the helical pipes connected to them.

The pressure vessel 12 is provided on its inner surface with a lining made of stainless or corrosion-resistant steel. In the event that liquid sodium comes into contact with the pressure vessel, the lining made of stainless or corrosion-resistant steel delays the erosion of the sodium until a sodium-water reaction occurs by means of suitable warning devices , tion. has been reported and corrective action has been taken. Inside the pressure vessel 12 and at a distance therefrom, a flow jacket 82 is provided, which is drawn outward into the sodium inlets 68 and above and below. lies below these inlets at a small distance from the inner surfaces of the pressure vessel. The flow jacket 82 is drawn inwards at its bottom part 84 and connects there to a sleeve or to a connection piece 86 which establishes a direct connection between the opening 74 and the sodium outlet 80. For insulation purposes there is ■ between the flow jacket. 8.2 and the pressure vessel 12 a “filling” of

BATH ORIGINAL

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Sodium, included, which, however, is not part of the sodium-> exit 80 can get, since the connecting piece 86 is provided at its lower end with a sealing ring 88, which against the inner surface of the sodium outlet 80 seals. As a result this sealing arrangement makes it possible to test and / or test the container lid and the "internal structure" of the superheater 10 Repair purposes from the main part 14 of the pressure vessel 12 to lift out, without parts of the lower seal between your bottom part 84- the Sbrö'mmgsmantelo 82 and dam Pressure vessel 12 must be solved. In a similarly simple way, the "internal structure" is back to its original position can be used by simply inserting it into the main part 14 of the Pressure vessel lowers, then the sealing ring against again the inner surface of the sodium outlet 80 seals.

If liquid sodium now flows in via the sodium inlet 68, it rises in the outside of the bundle support jacket 38 formed annular chamber slightly above the entry height. This creates between the tube bundle support jacket 38 and the central escape channel 42 an annular "stagnant" sodium body. This forms one in an advantageous manner Protection of the straight sections of the downspouts 36 against excessive Exposure to heat. In addition, it prevents damage to the central escape channel 42, which occurs when a Na'iriura-water reaction occurs the products of such a reaction up into an escape pipe 90 for nabrium-water reaction products leads away. This escape pipe 90 is expanded outward at its lower part to receive a hood 92 which the Directs sodium-water reaction products into the escape pipe 90 * The products of a sodium-water reaction are thus in this training in a largely unhindered and straightforward Flow path can be removed quickly so that they cannot cause excessive damage to the superheater.

All features and advantages of the invention that emerge from the claims, the document and the drawing, including constructive details, spatial arrangements and ORIGINAL

Failure steps can be either for themselves or in any combination essential to the invention.

SAD ORIGINAL 209839/0831 -

Claims (5)

3? a te η t _ & _ η S1 p_ rji c Ii e 1.ySodium heated superheater, characterized in that that an elongated, vertically arranged pressure vessel is an inlet for liquid sodium and is close by Bottom part has a sodium outlet that a tube bundle support jacket is arranged in and coaxially with the pressure vessel is in which a coaxially aligned with this!: · Escape channel is intended for sodium-water reaction products, that up to an area below the support jacket and the escape channel between these a number of downpipes extends downward, each of which by means of a connecting pipe is connected to a helical tube guided upwards between the support jacket and the pressure vessel, that saturated water vapor over the downpipes down through the connecting pipes and in the spiral pipes up again is feasible so that he means over the entrance down inflowing liquid sodium that rinses around the spiral tubes is superheatable, and that the Z wi sch. en space between the escape channel and the support jacket is filled with sodium., the The level of the sodium liquid filling is below the upper end of the escape channel. 2. Superheater according to claim 1, characterized in that the helical tubes are held by means of a holder are, which are from a Eohrbündel-Stützraantel enclosing Covenant and from an An ζ aiii of this covenant in radial direction protruding carrier composed, each carrier a number! Helical tubes supported. 8AD ORIGINAL 3 · superheater according to claim 2, thereby g e k e η η η ζ e i c h net that sur support of the helical tubes the carrier with riser tubes are connected 4- _t superheater according to one of claims 1 to 3 »characterized in that the tube bundle support belt is connected to an egg sheet above the sodium inlet and water vapor is passed through this sheet and that there is a Sanimelkaimüer on the upper side of the belt sheet. connected, which emits the water vapor via a water outlet " 5. Superheater according to at least one of claims 1 to 4, thereby g e k e η η ζ eichnet that the pressure vessel composed of a main container and a container lid attached to its upper part, and that the water vapor ex-itt is provided on the container lid. SAD 209839/0831 Blank page