Prediction of Foreign Object-Caused Fretting-Wear on Helical Tubes in the Single-Phase External Flow Field

This paper presents the prediction of fretting-wear on helical tubes caused by foreign object in an operating helical coiled steam generator. The thermal-hydraulic conditions of both tube side and shell side flow fields are predicted by a general purpose computational fluid dynamics code employing the finite volume element modeling. Modal analyses are performed for the finite element modelings of helical tubes to get the natural frequency, corresponding mode shape and participation factor. The wear rate of helical tube caused by foreign object is calculated using the Archard formula and the remaining life of the tube is predicted. Also, discussed in this study are the effects of flow velocity, internal pressure, tube-to-foreign object contact angle, and vibration of the tube on the remaining life of the tube.