DESIGN AND ANALYSIS OF HYDRO TURBINES FOR ELECTRICAL POWER GENERATION

In designing a hydropower plant, the design of turbine type depends on the head and water flow. Researchers suggest that Axial/Propeller turbines can perform efficiently in lower heads because of their high specific speeds, Francis turbines can perform efficiently in medium to medium/high heads with high water discharge and medium specific speeds whereas Pelton turbines can perform efficiently in high heads with low water discharge and low specific speeds. In this paper the output performance of Axial/ Propeller, Francis and Pelton turbines are designed, analyzed and compared using TURBNPRO software for the existing Jamshill Turen More HPP. The site head and water discharge are 117m and 305 m³/s. The feasibility recommends 4 vertical shaft Francis turbines. From the results we conclude that if a low head, high specific speed, Axial/Propeller turbine is designed for a medium head site, then its specific speeds exceed its limitations for the same electrical power output per turbine. Similarly, if a high head, low specific speed, Pelton turbine is designed for medium head site, then its runner diameter exceeds its limitations. Four Francis turbines can have the same electrical power output as a minimum of twelve Pelton turbines for the same medium head range