47 / 2024-06-07 10:04:56

Research on Acoustic Signal Characteristics and Location during Leakage of Reactor Primary Circuit Main Pipe

Aerodynamic noise model (FW-H); Large eddy simulation (LES); Acoustic emission detection method; Power spectral density (PSD); Cross-correlation method

In order to investigate the acoustic signal characteristics generated during the leakage process of the reactor primary main pipe, the acoustic emission method can locate the leakage point accurately. In this study, the aerodynamic noise model (FW-H) and the Large Eddy simulation (LES) turbulence model were used to numerically simulate three leakage pipes with different break sizes (2.5mm, 5mm and 10mm). The flow state of pipelines with different leakage apertures, the average sound pressure level and power spectral density (PSD) of monitoring points at different coaxial locations are obtained. The research results show that the characteristics of the leakage sound signal are mainly concentrated in the low frequency band below 500Hz. With the increase of the diameter of the break, the larger the average sound pressure level at the same position is, the more obvious the leakage characteristics are. The leakage hole is the turning point from high to low sound pressure level. Without considering the premise of system noise, the positioning accuracy of the break near the center of the two sensors is the highest, and the maximum positioning error does not exceed 1%, which has a high accuracy. The above research verifies the feasibility of acoustic emission method for the integrity detection of the main pipeline and serves the engineering practice.