抄録
The present study relating to corrosion in piping under the high-temperature and high-pressure conditions has been conducted for turbine and feedwater systems of the advanced thermal reactor (ATR) "Fugen", according to the request of the Japan Atomic Energy Agency (JAEA). The influence of the upstream bends on the flow field is important in the corrosion evaluation. Therefore, the 3D analysis has been carried out using the computational fluid dynamics (CFD) product code. The scope of the CFD modeling is limited in single-phase flow piping. The specification of the piping is approximately 14 m in length, and approximately 0.2 m in inner diameter. The pressure of the fluid is 9.5 MPa, and temperature approximately 115 ℃. The Reynolds number (Re) is approximately 6.4×10^6. The number of meshes of calculation scheme is about 2.7 million with hexahedral elements. Important parameters in terms of the corrosion evaluation are distributions of velocity and turbulent kinetic energy. Therefore, those values around the targeted piping are visualized and evaluated. Moreover, the thinning speed can be calculated by using those analytical results based on velocity magnitude. In the present study, an evaluation method using the turbulent energy is not practiced, because this method has not been established yet. The patterns of global flow and flow field such as velocity magnitude and turbulent kinetic energy at several regions near the wall are clearly understood by the present CFD analysis relating the flow passing the multiple bends.
