13 - Flow-induced vibrations in nuclear steam generators

Abstract

As pointed out in Chapter 1, heat exchangers are widely used in nuclear power plants and chemical processing plants. The main function of these devices is to transfer thermal energy between two fluids (primary and secondary). The secondary fluid flows on the outside of the heat exchanger while the primary fluid flows inside the tubes. In nuclear power plants, the primary fluid is often radioactive and hence the tubes are the barrier that prevents the mixing of these two fluids. Therefore, the integrity of these tubes is of major importance. Huge amounts of energy are transported inside these devices in the form of high pressure, and the temperature is quite high. If a tiny fraction of this energy is transferred to the structure in the form of vibrations, serious damage will take place. The aim of this chapter is to provide the reader with an overview of the mechanical issues associated with flow-induced vibration in tube bundles. In order to address these issues, the designer and the operators need to be familiar with the following: tube dynamic parameters, excitation mechanisms, vibration response predictions, and damage assessment.