INVESTIGATING THE MOTION CHARACTERISTICS OF COMPLEX-SHAPED FOREIGN OBJECTS ON THE SECONDARY SIDE OF A STEAM GENERATOR BASED ON CFD-DEM METHOD

Steam generator(SG) stands as a pivotal element within the primary circuit pressure boundary of nuclear power plants, functioning as a critical safety barrier against potential radioactive leaks. Throughout its operational lifecycle, the introduction of foreign objects(FOs) with diverse shapes into the secondary side of the SG may occur due to various factors, resulting in wear and tear on the pipes. Throughout its operational lifecycle, the introduction of foreign objects with diverse shapes into the secondary side of the SG may occur due to various factors, resulting in wear and tear on the pipes. To safeguard against substantial damage to the steam generator due to foreign objects, it is imperative to evaluate the distribution patterns of these objects and their potential impact on the steam generator. This study employs the Computational Fluid Dynamics-Discrete Element Method (CFD-DEM) coupling approach to develop a three-dimensional model of a steam generators feedwater ring. We have conducted an in-depth investigation into the movement characteristics exhibited by block-shaped foreign objects. By establishing a model for the interaction between foreign objects and the flow field, and considering the contact model of foreign object-wall interactions, we have achieved accurate prediction of the trajectories and distribution patterns of foreign objects within the steam generators feedwater ring.