Numerical Investigation on PBM Kernel Functions for the Internal Flow Field of a Steam Separator

Abstract In a nuclear reactor, the saturated steam generated by the steam generator needs to be dried by a steam-water separator, otherwise the impact and deposition corrosion of the steam droplets on the turbine blades will bring serious safety risks and reduce efficiency. In this work, the computational fluid dynamics software ANSYS Fluent combined with the population balance model is used to study the internal flow field of the steam-water separator. In order to correctly solve the internal flow field of the steam separator with PBM model, it is necessary to select the breakup kernel function and the convergence kernel function suitable for the internal working condition of the steam separator. The model of Luo and Svendsen (1996), the model of Lehr et al. (2002), the model of Coulaloglou and Tavlarides (1977) and the model of Prince and Blanch (1990) were selected. The relevant UDF was compiled and imported into the computational fluid dynamics software ANSYS Fluent, coupled with the PBM model for calculation, to solve the change of the volume fraction distribution of droplet agglomeration and crushing in the flow field of the steam separator, and the experimental results were compared. The influence of different kernel functions on the calculation results was explored, and the accuracy of the calculation of the separation efficiency of the water-steam separator under different kernel functions was analyzed.