[3J01-05] Anomaly Detection Technique and Robot

[3J03] Investigation on anomaly detection technique for cooling system device of sodium fast reactor by acoustic method

(3) Investigation on boiling sound characteristics

*Shota Tanaka¹, Yoshitaka Ueki¹, Masahiko Shibahara¹, Kosuke Aizawa² (1. Osaka Univ., 2. JAEA)

Keywords:Boiling Acoustics, Two-Phase Flow

In Sodium-cooled Fast Reactors, early detection of abnormalities such as coolant boiling phenomena with high accuracy is expected to improve safety. Acoustic measurement is one of the effective means for that, however, acoustic characteristics and generation mechanisms during boiling aren't well understood, although it is believed that they are related to bubble dynamics such as bubble generation and collapse. In this study, we investigated the basic mechanism of acoustic generation based on acoustic spectra. The generated sound was verified by changeing the subcooling degree, heat-flux, and audio equipment. As a result, the boiling sound frequency was correlated with the resonance of bending vibration of thin wire as a heat-transfer surface, suggesting that the vibration phenomenon of the heat-trasfer surface is one of the sound sources.