The effect of runner installation and design on the performance of gravitational vortex water turbine

ABSTRACT

Development in hydropower technology leads to modern and efficient technology. The emergence of gravitational vortex water turbine (GVWT) is a promising invention. It is suitable for harnessing energy from low head and flow rate water sources, ranging from approximately 0.7–2 m and 0.03–5 m³/s. A series of experimental studies had been conducted to develop the GVWT with a propeller runner. The objective of this study is to analyze the effect of runner design, including the number of blades, runner diameter and runner installation position, on the GVWT’s performance. A preliminary study on a dual-stage GVWT was carried out to increase the single-stage GVWT performance. The experimental result shows that 4-blade and 5-blade runners provide better performance than 3-blade runner and 6-blade runner. For a 5-blade runner, the optimal installation position is between 60% and 70% of depth. Installing a runner in the basin produces a blockage effect, which increase the runner performance. An extremely large blockage ratio causes stoppage which is undesirable. The maximum allowed blockage ratio is 0.8. The preliminary study on the dual-stage GVWT proves that it increases the GVWT’s performance. The efficiency of GVWT ranges from 25% − 50%.

KEYWORDS:

• Blockage
• dual stage
• hydropower
• installation position
• propeller
• vortex

Acknowledgements

The authors would like to express their sincere gratitude to the Ministry of Education and Culture and the Indonesia Endowment Funds for Education (PUSLAPDIK and LPDP) for providing financial support through a scholarship. The authors also wish to thank the Energy Engineering and Environmental Conditioning Laboratory and Mechanics and Fluid Machinery Laboratory for supporting this research.

Disclosure statement

No potential conflict of interest was reported by the author(s).