수력 현대화 개ㆍ대체 시 스파이럴 케이스와 흡출관 형상에 따른 모델수차 설계 적용사례 연구

Recently, turbines operating in hydro power plants are required to undergo renovation and modernization due to their age exceeding 30 years. In the process of renovation or modernization, a performance test of the scaled-down model is necessary to verify the performance of the real-size model. This model test method, with criteria that is similar to that of a real turbine, is the most economical and important method. Furthermore, the shapes of the runner and guide vane can be modified or replaced easily. However, during the process of modernization, the components with the spiral casing and draft tube are impossible to repair or replace because of the buried ground. Thus, in this study, numerical analysis is conducted to investigate the hydraulic performance based on the difference between the two-dimensional computer-aided design (CAD) shape and the real three-dimensional scan shape of the spiral casing and draft tube.