Abstract: This paper proposes a "V-shaped" ultrasonic transducer array for cleaning the inner walls of pipelines in the auxiliary systems of nuclear power plants, aiming to avoid the incomplete cleaning on the opposite side of the pipelines caused by the standing wave effect associated with the traditional "linear" arrangement of multiple transducers in ultrasonic cleaning. Multi-physics coupling simulations were performed by using Comsol to investigate the cleaning effect of the "V-shaped" array in the pipe. The simulation results show that when the ultrasonic excitation voltage is set to 400 V, and the three transducers in the "V-shaped" array are excited with phases of 0°, 45°, and 90°, respectively, the water field in the pipe is more evenly distributed. The maximum sound pressure reaches 157 kPa, exceeding the cavitation threshold, which induces cavitation. Additionally, the force exerted by the transducer array on the pipe′s inner wall deposits varies periodically. Based on these results, the voltage of 400 V and the excitation phases of 0°, 45°, and 90° are proposed as reference parameters for the cleaning process, providing an effective reference for the decontamination process of pipelines in nuclear power plant.

Key words: nuclear pipeline, ultrasonic cleaning, transducer array, Comsol simulation