Because of the complex fluid motion in hydraulic turbine and the imperfect design theory, the selection design of Large-scale hydraulic turbine is achieved based on the calculation and analysis on the synthetic characteristic curves, which is subjectivity and low efficiency. To solve this problem, the Gaussian mixture model is used to extract the geometric features from the synthetic characteristic curves so that the retrieval process of the model wheel can be achieved by these geometric features. The search model of the running area from the synthetic characteristic curves is build based on the contour curve similarity transformation method. In the paper, the Monte Carlo method is adopted to obtain the mean values of the synthetic characteristics in the running area so that the evaluation targets can be established by combining the mean values with the hydraulic turbine design experiences. Finally the validity of running area can be evaluated by the evaluation targets. The test results show that the accuracy and efficiency of the selection design of Large-scale hydraulic turbine can be improved by the proposed method.
PL
W artykule przedstawiono problemy projektowania dużych turbin hydraulicznych. Zaproponowano model matematyczny bazujący na mieszanym modelu Gaussa w celu wydobycia parametrów geometrycznych. Zaadaptowano metodę Monte Carlo do określania średnich wartości syntetycznych charakterystyk w obszarze pracy.
Discharge measurement using the pressure-time (Gibson) method typically involves mounting measurement instrumentation on the outside of the penstock. In the case of a hydropower plant where the penstock is built over concrete, an innovative approach is necessary in order to install instrumentation inside the penstock. Such instrumentation has been implemented for the purpose of efficiency tests of the upgraded small Kaplan turbine. The pressure-time method, in its classic version, requires sending pressure signals from both penstock cross-sections to the differential pressure transducer by means of connecting tubes. This raises the question on the influence exerted by dynamic properties of the connecting pipes/transducer system on the discharge measurement results. Calculations carried out using previously developed method enable authors to demenstrate that the connecting pipes/transducer system had exerted a negligible influence on the discharge measurement results.
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The present study concerns with the analysis and modeling of thread connections of hydroturbine units mountings. The boundary element method scheme for the numerical analysis of a problem is proposed. Various contact models of the screw and the flange are considered. Based on the presented numerical results using the least squares method the convenient engineering formulae for determination of the stress concentration in thread connections, which considers not only the root radius, but also sliding friction factor between contacting surfaces, is constructed.
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Turbiny hydrauliczne w elektrowniach wodnych. W elektrowniach wodnych w zależności od spadu, natężenia przepływu (przełyku) oraz sposobu pracy stosowane są turbiny hydrauliczne (wodne): - akcyjne - Peltona (rys.1), o przepływie poprzecznym (Banki-Michella) (rys. 2); - reakcyjne - Francisa (rys. 3), Deriaza (rys. 5), Kaplana (rys. 6), śmigłowe (rys. 4). Turbina napędza generator synchroniczny bądź asynchroniczny bezpośrednio (duże instalowane moce) lub poprzez przekładnię mechaniczną zębatą bądź pasową (małe moce).
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A new concept of the interstage seal for lateral vibration control and modification of dynamic behavior of the flexible rotor of the hydraulic recovery turbine is analyzed. The industrial solution and experimental verification of the presented idea are shown as well.
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In this work, we determine the optimal shape of a labyrinth seal in a hydraulic Francis turbine. The numerical approximation of the optimal shape is obtained using shape optimization techniques. The flow is governed by Navier-Stokes equations. We first prove the existence of an optimal domain, and later we present the computation of the shape gradient which allows us to approximate numerically the optimal domain.
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