DETERMINATION OF FLOW RATE AT LOW HEAD HYDRO POWER PLANTS FEATURE WITH KAPLAN TURBINES
In the paper there are presented some methods of determination of the flow rate measurements in low head hydro power plans are also presented with a series of field studies. The most commonly used method for determining the flow in convergent measurement sections is the multipoint velocity measurement with propeller type current meters. For flow rate evaluation integration of the difference between measured velocities and a known velocity distribution is recommended. One of the newest methods of flow determination in intakes is the acoustic scintillation method, a cross-correlation method. For accurate results the scintillation method must be installed downstream of trash racks. Another method that can also be adopted to measurements in low head, is method of acoustic transit measurement, but new procedures for determination weighing the individual path velocities have to be applied due to varying shape of the flow cross sections. At the end of the paper a comparative analysis is made between the methods for determining the flow rate in the convergent measuring sections
Keywords: flow rate measurement, Winter-Kennedy method, efficiency, acoustic scintillation, acoustic transit time, velocity – area Cuvinte cheie: măsuratori debitmetrice, metoda Winter-Kennedy, randament, metoda scintilaţiei acustice, metoda acustică a timpului de tranzit, metoda viteză– arie