Research on steam flow excited vibration of nuclear power condenser based on full three-dimensional numerical simulation technology

Numerical calculation is regarded as the most effective research method for studying problems about a condenser due to the experimental difficulty caused by the huge size. However, almost all numerical research studies about condensers are two-dimensional, which severely reduce the reliability of the research about a three-dimensional problem. In this case, a full three-dimensional computational fluid dynamics (CFD) method based on a porous medium model was first used to study the seawater leakage event in a condenser. The steam flow field of the condenser under a series of operation conditions was obtained. The distribution of a risk coefficient of steam flow excited vibration (SFEV) was obtained as well. The results show that the sweep velocity of steam across a titanium tube was the primary factor determining the risk coefficient of SFEV. The risk of SFEV of the outer layer in the upper finger joint region is relatively high. It is necessary to install anti-abrasive strips or implement preventive tube plugging. According to the calculated results, the recommended values of electric power limits for a nuclear power unit were given, which was 840 MW under half-side condenser operation conditions in summer. Through comparing the simulated flow field before and after tube plugging, it is found that local tube plugging in the high-risk area will transfer the position of the high-risk point of SFEV.