LIQUID CONTROL JET DURING PART LOAD OPERATION IN A HYDRAULIC TURBINE

摘要

A method and system to mitigate the pressure fluctuations in hydraulic turbines, operated at partial load, by injecting high velocity control jet (50) or jets of liquid downstream of the turbine runner, on the upper portion of the draft tube (22), along the machine axis; the liquid jet(s) flow rate can be adjusted continuously depending on the pressure fluctuation level in the draft tube, so as to control the swirling flow downstream of the runner and avoid helical vortex breakdown at partial load regimes, thus eliminating the main cause of pressure fluctuations.