펌프장 흡수정의 와류 강도를 고려한 최적 설계에 관한 연구

Abstract

The vortex which generated around suction region of a pump sump causes problems such as damage to the pump, increase in maintenance costs, and failure to supply coolant smoothly. Therefore, it is essential to analyze the vortex for proper pump sump design. The common method to investigate the vortex behavior around the sump pump is by Computational Fluid Dynamics (CFD) simulations. Although the CFD simulations provide high efficiency in analysis time and resources, it is insufficient to predict accurate the vortex behavior especially in scaled model. Thus, the vortex analysis by CFD simulations and experiments was conducted in this research to obtain high accuracy and validation in the results. There are 2 types of the vortices in the pump sump, type 2 of sub-surface vortex and type 3 of free-surface vortex, are used for the pump sump design based on ANSI HI 9.8 2018 standard. This study conducted the model test to validate a suitable CFD simulation method by identifying the vortex. The dye test and PIV(Particle Image Velocimetry) technology were used to visualize the 2 types of the vortex, whereas the PIV vorticity results were compared to the CFD results. Velocity analysis was conducted to find the influence of the flow entering the bell. To apply the finalized result from the PIV and CFD analysis, there were CFD simulations for vortices by real scale pump sump and modified models regarding the mainly applied in industry diameter of bell. Finally, related equations could be found for 2 kinds of vortices of the behavior regarding the results.