Question

A Francis turbine has the following information:

Pressure head supply into turbine HNet = 300 m of water, • Q = 10 m3/s, • N = 400 rev/min, • Runner diameter Drunner = 3m, • Runner inlet width Br = 0.5 m, • Velocity (absolute) at the inlet Vai = 15 m/s, • Draft tube gives 2 m height before water exits, • Overall efficiency ɳo = 80 % Assuming radial outlet and ignore losses across the guide vanes and runner. Calculate:

1.1. The output power? ANS: +/- 24.6 MW

1.2. The guide vane angle? ANS: +/- 8.1 deg

1.3. The runner vane angle at inlet? ANS: +/- 2.93 deg

1.4. The relative velocity at runner entry? ANS: +/- 41.46 m/s

Answer 1