Investigation on internal flow of draft tube at overload condition in low specific speed Francis turbine
نویسندگان
چکیده
منابع مشابه
Determination of Hydroacoustic Draft Tube Parameters by High Speed Visualization during Model Testing of a Francis Turbine
Francis turbines can experience critical instabilities at high load operating points, limiting their maximum power output. The swirling flow developed in the draft tube produces a cavitating axisymmetric volume, acting as an internal energy source leading to a self-excited surge phenomenon. The pulsation of the vortex rope corresponds to one of the eigenfrequencies of the hydraulic system. Effo...
متن کاملNumerical Study of a Pipe Extension Effect in Draft Tube on Hydraulic Turbine Performance
Draft tube of Francis type hydraulic turbine usually consists of: cone, elbow and diffuser. On the contrary, in some power stations an extra pipe should be added to the draft tube at the bottom of cone because of installation limitation. In this paper, this special case has been numerically studied. To this end CFD analysis was applied to simulate all parts of hydraulic turbine. A homogeneous m...
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A general method for testing nonlinearity in time series is described and applied to measurements of different pressure data inside the draft tube surge of a real Francis turbine. Comparing the current original time series to an ensemble of surrogates time series, suitably constructed to mimic the linear properties of the original one, we was able to distinguish a linear stochastic from a nonli...
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This paper presents the results of simulations of the complete three-dimensional fluid flow through the Spiral Casing, Stay Vane, Guide Vane, and then through the Francis turbine runner of the Derbendikan power station. To investigate the flow in the Francis turbine and also to identify the loads acting on the turbine blades, a three-dimensional model was prepared according to specifications pr...
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Hydropower plants may be required to operate in synchronous condenser mode in order to supply reactive power to the grid for compensating the fluctuations introduced by the intermittent renewable energies such wind and solar. When operating in this mode, the tail water in the Francis turbine or pump-turbine is depressed below the runner by injecting pressurized air in order to spin in air to re...
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ژورنال
عنوان ژورنال: IOP Conference Series: Earth and Environmental Science
سال: 2016
ISSN: 1755-1307,1755-1315
DOI: 10.1088/1755-1315/49/8/082016