Abstract
Flow accelerated corrosion (FAC) is observed in nuclear and thermal power plant. And it sometimes caused serious problem. FAC is caused by water chemistry effects and hydrodynamic effects. The hydrodynamic effects is represented by mass transfer effects. There are many elbows and T junctions, orifices, header pipes in plants. The flow condition is very complex in these elements. FAC is influenced by flow conditions. This is why it is important to reveal flow conditions in these elements. There are many research about elbows and T junctions, orifices. However, there are a few research about header pipe. And it is difficult to visualize the flow conditions in header tubes by experiment. In this presentation, numerical simulation is performed for evaluating the relationship between flow rate and mass transfer coefficient. The maximum mass transfer rate is overserved outlet pipe near inlet pipe in any flow volume. And mass transfer coefficient increases when flow volume increases.
