Numerical investigation of thermal-hydraulic characteristics in a steam generator using a coupled primary and secondary side heat transfer model

A coupled primary and secondary side heat transfer and thermal phase change model is used to investigate the thermal-hydraulic characteristics of a steam generator (SG) at Daya Bay Nuclear Power Plant (DBNPP). The simulation results reasonably reveal the ununiform boiling behavior in the secondary hot and cold legs. Vapor velocity is slightly higher than that of water and the corresponding slip-ratio first increases rapidly before gradually decreasing in the secondary hot leg and cold leg regions, a result which agrees with predictions using the drift-flux model. Cross-flow energy, which accounts for flow-induced vibration (FIV) at the U-bend tubes, is determined with the aid of localized thermal-hydraulic distributions, and the resulting FIV damage is predicted to be most severe at 0.35 m on the cold leg side and -0.2 m on the hot leg side of the U-bend region, respectively. These FIV damage predictions agree with measured plant data for the prototypical SG, showing that this model can provide the use information to improve thermal-hydraulic characteristics and help alleviate FIV damage in a SG. (C) 2012 Elsevier Ltd. All rights reserved.