Answer Happy

(a) A Francis turbine produces 1 MW of electrical power. The sum of the electrical losses in the generator, all mechanical losses and all hydraulic losses between water inlet to the spiral casing and downstream basin amounts to 76% of the available geodetic head of 54 m. The head loss in the pipeline feeding the turbine is 3 m. Determine the water volume flow rate of the turbine assuming water density of 1 kg/dm3. (15 marks) (b) The runner of the Francis turbine has 16 blades, is connected to a generator with 5 polar pairs that generates electricity at a frequency of 50 Hz, and has electrical efficiency of 96%. The power lost to mechanical losses is 50 kW. Calculate the torque exerted by each blade on the turbine rotor rim. (17 marks) (c) At the runner inlet, the angle of the relative velocity of the water coincides with the runner blade metal angle, and the inlet guide vanes are at 30 degrees with the velocity of the runner. The mean diameter of the runner inlet is 1 m, and the meridional component of the flow velocity at the mean diameter of the runner inlet is 35 m/s. Determine the blade metal angle at the runner inlet, and draw as accurately as possible the velocity triangle at this location. (18 marks)