Optimization Design And Operation Reliability For Hydraulic Turbine

The hydraulic turbine runner is the core component of energy conversion of hydropower unit and its performance has important influence on the power unit operation and power grid steady. Improving the effectiveness of hydraulic turbine, cavitations performance and stability always is the goal for the hydraulic turbine researcher and designer. To reach the goal, the runner is designed optimally by CAGD(computer aided geometry design) and modern optimal algorithms and combining the numerical simulation, simultaneously the reliability of the hydropower unit operation is studied. The study mainly has following points:1. NURBS parameterization method of the blade surface is proposed, based on it, the matrix linear equations of solving control point from the data points is derived. The tensor product curved surface equation is applied to transform the blade surface in space point matrix, which has a fine interface to the current software. The free surface is extended and imperfect information of blade is recruited by LMS. The deformation of blade during forming process is avoided.2. The quality valuation method of blade is build. Firstly, the measurement error caused by surface cleanliness and boundary integrality is eliminated by recursion mid-value filter and moving mean method, the data reliability is improved. Secondly, the discrete curved surface measurement data is reconfigured by improved multi-step approximation algorithms, based on it the surface quality evaluation is obtained by comparing the known data point of measured blade surface with reconfigured surface.3. The adaptive GA is developed for the prematurely and slow convergence of standard GA, the performance of modified GA is estimated by test function. The AGA is applied to multiple target optimal design of cascade, which decreases the water head loss coefficient and cavitations coefficient, so the optimal algorithm is viable.4. The redesign of hydraulic turbine runner is carried out based on CFD technology for a certain hydraulic power plant. All the performance data of runners before redesign and after redesign is compared by model experiment. The result shows that the optimized efficiency of remodeling runner is perfectly improved and the high-efficiency band is broaden. At the same time, the cavitations coefficient and pressure fluctuation magnitude is reduced and the expected goal of redesign and optimization is reached.5. The fault mechanism and vibration frequency characteristic of hydropower unit is analyzed and summed up. The method on de-noise and feature extraction of fault signal by wavelet analysis is discussed, according the measurement vibration data of a unit of some hydropower, the fusing diagnosis is made by information fusion method based on D-S evidence theory, the prepositional measure is proposed according to the diagnosis result.