Numerical Simulations of Flow Field in First-Stage Steam-water Separator of Steam Generator

Taking the first-stage steam-water separator of the steam generator of PWR nuclear power plant as the research object, the flow field characteristics and steam- water separation performance of wet steam after entering the steam-water separator are simulated by using the computational fluid dynamics (CFD) calculation software ANSYS Fluent. In the simulation process, a calculation model combining the Euler multiphase flow model and the k-ε Realizable turbulence model is used. The simulation results of the working medium flowing through the steam-water separator show that when the vapor phase and the liquid phase flow to their respective outlets through the steam-water separator, there is obvious stratification. Comparing the simulation results under different tangential outlets and droplet diameters, it is shown that the larger the outlet area, the better the separation effect of the separator on droplets; In the diameter range of 0.01-0.10 mm, the larger the droplet diameter, the better the separation effect.The simulation results of the separation efficiency of the steam-water separator under different load conditions show that the separation efficiency slightly decreases with the increase of the unit load.