Wear work-rate measurement for different steam generator tube layouts in two-phase cross flow

Abstract

Tube-to-support contact damage is directly related to the wear work-rate in steam generator tube bundles. Generally, the work-rate is related to two main factors: the contact force between the tube and the supports, and the sliding distance during this contact. This work presents an experimental study of the wear work-rate of the APR1400 steam generator tube bundle array layouts. The three array layouts, rotated square, rotated triangle and normal triangle, are tested in single phase and two-phase flow. The test apparatus was designed to accurately measure the work-rate of the three arrays. The approach followed in this work is to appropriately measure the contact force and sliding distance during the impact, which leads to an accurate calculation of the work-rate. Based on the results of this study, array layout effect on the work-rate was analyzed by statistical analysis. The measurements were performed for different flow velocities, covering a wide range to include post- and pre-critical flow velocity of each array. Results showed a substantial difference in the mean work-rate between the rotated square array and the triangular arrays. Furthermore, the larger gap size between the vibrating tube and the supports resulted into higher work-rates for all void fractions.