CDF에 의한 입형 다단 원심펌프 성능해석에 관한 연구

Abstract

In Korea, most companies modify to make some similar pumps, but highly efficient vertical multi-stage pump is almost imported from foreign companies like Grundfos, Ebara, Wilo, Salmson. Like this case, the technology of multi-stage pump design needs extensive knowledge related to fluid dynamics, and it is one of the hardest part which needs both theoretical and empirical aspect. Even though we make a plan to make a prototype product, a turbo machine needs much cost for manufacturing, so it is hard to rely on experiment to prove the exactness of the prototype machine. Due to these reasons, many companies are using a commercial code to analyze the flow of turbo machine. The purpose of this study is focused on the characteristic of flow and performance analysis of vertical multi-stage pump with optimum shape. Until now, the design of impeller and guide vane has relied on experience of designer because of many mechanical and geometrical variables. Vertical multi-stage centrifugal pump needs not only experience of designer but also judgement of that in making three-dimensional hub and shroud curve of impeller and guide vane. But, it needs much time to design hub and shroud curve of meridional section. So, in this study, we used a commercial CFX-Bladegen to shorten much time that was spent in design. And, a commercial CFD code (TASCflow) was used in the calculation region by changing flow rate 10 to 26 ㎥/h at the constant 3500rpm in case of one-stage.

The numerical analysis was performed by 4 cases of design condition. First, there is the performance analysis using experimental factor. Second, there is the performance analysis accoridng to the variation of inlet breadth of impeller. Third, there is the performance analysis according to the height variation of impeller located within the guide vane. Fourth, there is the performance analysis according to the variation of inlet angle of guide vane. And The results of numerical analysis were compared with the data of Grundfos pump.