Experimental Investigation for Acoustic Resonance in Tandem Branches Under Each Dry and Wet Steam Flow

Abstract

Flow-induced acoustic resonances of piping system containing closed side-branches are sometimes encountered in power plants. In the United States, the steam dryer in boiling water reactor had been damaged by high cycle fatigue due to acoustic-induced vibration under a power uprating condition. The steam piping systems of current power plants often have nearly saturated wet steam condition. The side-branches of current power plants vary in their configuration (single, tandem, and coaxial), number, and so on. Therefore, many types of flow-induced acoustic resonance at branch piping have been investigated by many researchers. However, most of previous studies were under air flow condition and there were few previous experiments under wet steam flow. In this study, some types of the acoustic resonance at branch piping are investigated by conducting experiments under each dry and wet steam conditions. As a result, it is clarified that influence of branch configurations (single or tandem) on resonance amplitude and frequency under steam flow. In addition, their differences between dry and wet steam are discussed.