CFD investigating the influence of power uprate on impingement wear sites for the feedwater heater in the nuclear power plant

Power plant licensees have been adopting the power uprate as an efficient way to increase the thermal energy and the electrical output. Feedwater heaters (FWHs) are the significant equipments to improve the efficiency of energy generation for a power plant. However, the wall thinning may cause a leakage on the FWH shell wall and subsequently results in the power plant derating or shutdown. Therefore, a computational fluid dynamics (CFD) model coupled with the droplet impingement wear model is proposed to investigate the influence of power uprate on the impingement wear sites on the FWH shell wall. Based on the simulation results, the CFD model can reasonably capture the three-dimensional distributions of droplet flow and its rebound characteristics. The predicted wear sites also show good agreement with the plant measured data. Therefore, the present models can provide the useful analytical tool for the plant licensees to assess the impacts of power uprate on the wear site distributions for the FHWs. The calculated comparisons between the original rated power and the power uprate conditions imply that the characteristics of droplet behaviors and the distribution trends of impingement wear sites are not significantly influenced even though the plant thermal power is elevated by 10%.