Arrangement for preventing the formation of cracks on the inside surfaces of feedwater line nozzles opening into pressure vessels

Abstract

Abstract Arrangement for the prevention of crack formations at the inside surfaces of feedwater line nozzles (13) which open into pressure vessels, especially nuclear reactor pressure vessels or steam generators. The feedwater is introduced into the water/steam space (II) of the pressure vessel (DE) via a substantially horizontal line section (140) and a rising line section (141) following downstream thereof up to the overflow edges U at the end of the flow travel of the rising line section (141). From there, the feedwater is admixed to the medium in the water/steam space (II) or the descent space (8) of the pressure vessel (DE) via a downward-directed line section (141) and optionally, via a ring feedline (12) connected thereto. This prevents temperature stratification due to backflow of warmer water in the nozzle. It is important here to make the ratio A n /D i as small as possible. In practice it has been found to be feasible to provide a ratio which is approximately within the limits 0.5 and 2. (A n ) here refers to the horizontal distance of the pressure vessel inside wall from the center line (M u ) going through the center of gravity of that cross-sectional surface which is defined by the overflow edges (U). (D i ) refers to the inside diameter of the feedwater line opening into the pressure vessel.

Inventors

• 👤 Hans Mayer
• 👤 Zvonimir Sterk

Bibliographic Details