Study of flowmetering stations in hydraulic turbines at hydroelectric plants: Fid-Bau Portal

Study of flowmetering stations in hydraulic turbines at hydroelectric plants

Danilov, A. E. / Lyakhov, V. F.

Conclusions For carefully constructed flowmetering stations, calibration curves are quadratic, irrespective of whether we use the principle of measuring the differences in centrifugal forces in a curved stream in the spiral chamber, or the pressure difference at points in the conduit with different velocities.The calibration curve for flowmetering stations in spiral chambers remains constant with significant head variations; consequently, flowmetering stations can be used to measure discharges during the entire filling of the reservoir, the units being started under low heads.Calibration factors obtained from tests of one of the units cannot be directly extended to other monotypic units operating in the same plants, even if their flowmetering stations are built in accordance with the same plan, since errors associated with inaccurate placement of piezometers are possible in this case.To standardize measurements of turbine discharge, it is necessary to develop standard tolerances for setting the position of piezometers in the spiral chambers.For certain conduit designs the nonuniformity of discharge distribution in the turbine intake section may affect the calibration curves of flowmetering stations.