| 摘要 |
Arrangement for avoiding crack formation on the inner surfaces of feed-water pipe pieces (13) opening into pressure vessels, in particular nuclear reactor pressure vessels or steam generators. The introduction of the feed water into the water/vapour space (II) of the pressure vessel (DE) takes place via an essentially horizontally running pipe part (140) and, following this, a rising pipe part (141) as far as overflow edges (Ü) at the flow path end of the rising pipe part (141). From there, the feed water is, via a downwardly directed pipe piece (142) and if appropriate via an annular feed-in pipe (12) connected thereto, added to the medium in the water/vapour space (II) or in the fall space (8) of the pressure vessel (DE).As a result, a temperature layering due to flowing back of warmer water in the pipe is prevented. In this connection, it is important that the An/Di ratio is dimensioned to be as small as possible. A ratio which lies approximately between 0.5 and 2 has proved to be workable in practice. (An) means here the horizontal spacing of the pressure vessel inner wall from the central line (Mu'') which runs through the centre of gravity of that cross-sectional surface which is spanned by the overflow edges (Ü). (Di) means the inner diameter of the feed-water line which opens into the pressure vessel. <IMAGE>
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