NUMERICAL SIMULATION IN FRANCIS TURBINE UNDER PARTIAL LOAD CONDITIONS

• Main Author: Zakaria, Yahya
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/75942
• Institution: Institut Teknologi Bandung

<p align="justify">Indonesia has a significant potential for renewable energy sources. The largest contributor to renewable energy generation is hydroelectric power plants (HEPP). According to data from the Ministry of Energy and Mineral Resources, as of 2021, HEPP accounted for 59% of the total renewable energy capacity. Hydroelectric power plants are expected to operate continuously to ensure electricity availability, both during base load and peak load conditions. However, the actual electricity demand fluctuates over time. Operating at low loads can lead to flow deteriorations, including vibration. This research aims to model and analyze a Francis turbine in a partial load operation at Cirata Hydro-Electric Powerplant. Simulation of the Francis turbine using ANSYS Fluent, which is based on Computational Fluid Dynamics (CFD). The turbine capacity used in this study is 126 MW. The components, such as the spiral case, stay vane, guide vane, and draft tube are modeled based on engineering drawings, while the runner model was obtained from 3D scanning. The developed Francis turbine model has been well-validated and can accurately represent the actual conditions. Simulation conducted under various partial load conditions to study the flow characteristics, cavitation patterns, and turbine performance. The simulation results revealed flow irregularities, the presence of numerous vortices, and the highest level of cavitation at a 40% partial load. The addition of baffles on the draft tube walls reduced the formation of a vortex rope and improved the turbine efficiency by 0.17%.