| 摘要 |
<p>The system is for the construction of a grille supporting and positioning steam generator tubes, particularly in natural-circulation pressurised water reactors. The grille proper is formed by strips of material having a particular coefficient of thermal expansion, and the frame of another material with a lesser or equal thermal expansion coefficient. The other frame is joined to the strips during assembly, so as to be fixed to them for the whole time necessary for construction, transport and erection. When the generator is set to work the frame is no longer fixed to the strips. Thus is encloses and supports them but allows them to expand at a different rate.</p> |
