Francis turbine without Guide vanes for sediment affected projects

Supervisors / Advisors

Prof. Hari Prasad Neopane

Dr. Biraj Singh Thapa

Dr. Sailesh Chitrakar

Prof. Baoshan Zhu (Tsinghua University)

Objectives

1. Identify the design methodology of Francis turbine without guide vanes for minimizing sediment erosion effect

2. Investigate the effects of sediment erosion in the runner of guide vaneless Francis turbine

3. Investigate the flow field between runner and stay vanes for guide vaneless turbine

4. Optimize relative velocity for variable speed operation of Francis turbine without Guide vanes

Summary

Leakage flow from the clearance gap of GV in conventional Francis turbine affects significantly to runner, eroding GV profile as well as runner blade. This research study focus on investigation of high head Francis turbine without guide vanes. Guide vaneless Francis turbine design aims to minimize the sediment erosion affects in hydropower plants. Furthermore, this study aims on variable speed operation of such type of turbines. Thus, both effects of leakage flow as well as effects of off-design operation of Francis turbine can be minimized.

Design method of Francis turbine implements conventional Fixed speed operation of the runner. Reference runner blade is investigated at variable operating condition. The runner blade profile is optimized using multi-objective optimization technique to improve the performance at overall operating condition. Thus, efficiency of the runner was improved at part load and full load condition thus significantly reducing the sediment erosion effects.