Seite - 1373 - in Book of Full Papers - Symposium Hydro Engineering

In order to verify whether the increase of the available hydraulic power is reached by an increased turbine head or an increased turbine flow rate the diagram below provides a more detailed analysis of the measurement results. The diagram presents the turbine flow rate QTu and the turbine head HTU plotted against the total flowrate Q for the situation with and without ejector. Fig. 12 Turbine flow rate and turbine head measured with and without ejector It turns out that the ejector effect does not only cause an increase of the turbine head HTu but also of the turbine flow rate QTu which is – though decreasing – higher than the “normal” turbine flow rate. This is due to a suction effect closely connected with the reduction of the tail water level at the draft tube outlet. 1373