2,176 research outputs found

    Analysis on Hydraulic Design of Runner Blades of Francis Turbine

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    Francis turbine is the most widely used model in hydropower station, and the hydraulic design of runner blades affects the efficiency of the unit. This paper discusses how to complete the hydraulic design of Francis turbine runner blades according to the given parameters. In hydraulic design of Francis turbine runner, firstly, the structural scheme is determined according to the given parameters. On the basis of referring to excellent hydraulic model, a Francis turbine runner blade is designed according to the given head. By analyzing and calculating the data, the geometric parameters and axial projection of the Francis turbine runner flow channel are determined, and the axial flow network is drawn and checked, so as to complete the calculation of axial vortex line and blade drawing. Finally, the airfoil is thickened by a certain thickening principle

    Influence of the boundary conditions on the natural frequencies of a Francis turbine

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    Natural frequencies estimation of Francis turbines is of paramount importance in the stage of design in order to avoid vibration and resonance problems especially during transient events. Francis turbine runners are submerged in water and confined with small axial and radial gaps which considerably decrease their natural frequencies in comparison to the same structure in the air. Acoustic-structural FSI simulations have been used to evaluate the influence of these gaps. This model considers an entire prototype of a Francis turbine, including generator, shaft, runner and surrounding water. The radial gap between the runner and the static parts has been changed from the real configuration (about 0.04% the runner diameter) to 1% of the runner diameter to evaluate its influence on the machine natural frequencies. Mode-shapes and natural frequencies of the whole machine are discussed for all the boundary conditions testedPostprint (published version

    Obtaining the CAD Flow Models in the Francis Turbine of the Sancancio Hydroelectric Power Plant by Means of Reverse Engineering

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    This article presents the process for obtaining the CAD flow models in a Francis turbine. The analysis stage in this turbine includes the use of the latest generation optical equipment to obtain the surfaces of each of the component elements of the Francis turbine. After obtaining 3D scans, is used special software for CAD modelling and reverse engineering to extract the complex NURBS surfaces of several of the main components of the turbine and finally the flow volumes which are of vital importance in the previous studies of the research called CFD computational analysis of the influence on the opening of the blades in a Francis turbine on the side of the suction ring in the small hydroelectric power station of Sancancio belonging to the CHEC S.A E.S. P EPM Grou

    Modeling of the dynamic response of a Francis turbine

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    The paper presents a detailed numerical model of the dynamic behaviour of a Francis turbine installed in a hydroelectric plant. The model considers in detail the Francis turbine with all the electromechanical subsystems, such as the main speed governor, the controller and the servo actuator of the turbine distributor, and the electrical generator. In particular, it reproduces the effects of pipeline elasticity in the penstock, the water inertia and the water compressibility on the turbine behaviour. The dynamics of the surge tank on low frequency pressure waves is also modelled together with the main governor speed loop and the position controllers of the distributor actuator and of the hydraulic electrovalve. Model validation has been made by means of experimental data of a 75 MW—470 m hydraulic head—Francis turbine acquired during some starting tests after a partial revamping, which also involved the control system of the distributor

    Francis turbine runner design

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    Tato diplomová práce slouží jako podklad pro rekonstrukci malé vodní elektrárny Harta. Součástí této rekonstrukce je detailní zpracování lopatkování oběžného kola na základě hydraulického návrhu na dané parametry lokality. Výsledkem je model dvojité Francisovy turbíny v numerickém zpracování jako předloha pro výrobu odlitku kola slévárnou. Tento model byl zpracován pomocí softwaru SolidWorks.The graduation theses are focused on reconstruction of the small hydro-electric power station Harta. Design of detailed runner blading based on the parameters of the given location is part of the reconstruction. Model of the duplex Francis turbine for cast manufacturing is result of the graduation theses. Numerical description of the model was carried out using SolidWorks software.

    Проектирование рабочих колес радиально-осевой высоконапорной гидротурбины на параметры ГЭС КАМЕНГ

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    Приводиться опис сучасних пакетів прикладних програм для проектування й розрахунку гідротурбін. Дається опис розробленого комплексу прикладних програм для проектування робочих коліс радіально-осьової гідротурбіни. Показано використання розробленого комплексу при про-ектуванні робочих коліс радіально-осьової гідротурбіни на задані параметри ГЕС.The description of modern packages of applied programs for designing and calculation of hydroturbine is resulted. The description of the developed complex of applied programs for designing of runners of the Francis turbine is given. Use of the developed complex at designing of runners of the Francis turbine on the set parameters of Hydroelectric Power Station is shown

    Влияние гидродинамических характеристик элементов проточной части на энергетические показатели радиально-осевой гидротурбины

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    В данной работе определяются гидродинамические характеристики элементов проточной части гидротурбины. Устанавливается влияние гидродинамических характеристик на формирование энергетических характеристик радиально-осевой гидротурбины. На основании опытных данных определяется структура и параметры зависимости коэффициента потерь от геометрических и режимных параметров.In the given work hydrodynamic characteristics of elements of a flow space of the Francis turbine are defined. Influence of hydrodynamic characteristics on formation of power characteristics of the Francis turbine is established. On the basis of the skilled data the structure and parameters of dependence of factor of losses of the runner from geometrical and regime parameters is defined

    Development of a 5kw Francis Turbine Runner Using Computation Fluid Dynamics

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    A small scale Francis turbine runner for a turbine located at Awba dam in the University of Ibadan with designed head and flow rate of 6m and 0.244m3/s is designed. The basic design of the Francis turbine runner is completed based on basic fluid dynamics turbo machinery principles. A 2-D and 3-D steady state, single-phase CFD analysis is conducted for the runner, stay vanes, guide vanes, spiral case and draft tube of Francis turbine using two commercial CFD codes (ANSYS FLUENT and Solidworks Flow Simulation). The dimension of the runner is obtained from empirical formulas using the available head and flow rate. The runner is then optimized using CFD analysis to get required shape and performance. Performance of turbine is predicted at different guide vane openings. Cavitation and flow separation analyses are also conducted using a 2-D, steady state and two-phase (water vapour and liquid water) in order to reduce their occurrence in the designed runner. A hydraulic efficiency of  68.2% was obtained.Keywords: Fluid dynamics, hydro-turbines, cavitations, CFD, flow separatio

    Numerical and Experimental Study on Vortex Rope with MGV in the Micro-Class Hydro Francis Turbine

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    Energy consumption is a huge part of our daily life. Today we gather most of our energy from coal, oil and natural gas also known fossil fuels. Generating electricity on our planet, requires plenty of massive power plants and transmission grid system delivery to the power. Renewable energy comes from a source that is not depleted when using such as wind, solar and hydropower. Hydropower is the largest source of renewable energy which is capture the energy of falling water to generate electricity as well can be efforts produce number of benefits such as a water supply, flood control and irrigation system. Micro-hydropower installation can provide power to the out-settlement or small community. These usually range between 5kW-100kW of electricity output. In this study, numerical and experimental analysis of 3kW micro-class Francis turbine carried out to predict performance of the turbine. A Draft tube is one of the most important part of Francis turbine which connects the runner exit to the tailrace where the water is being finally discharged at atmospheric pressure from the reaction turbine. There are several issues in the draft tube like pressure pulsation, effect of cavitation on draft tube performance, vortex rope study etc. At part-load condition vortex form it hits structure constantly which is affect the performance of the turbine. This study focused on prediction of vortex behavior at the draft tube and numerical results obtained the hydraulic performance of 3kW micro-class Francis turbine with the inlet pipe, a spiral casing with 12 guide vanes, 6 stay vanes and the runner having 13 blades and a draft tube. Ansys CFX software used to simulate for the numerical analysis of micro-class Francis turbine. Three misaligned guide vane (MGV) openings with 5 different MGV openings were chosen to analyze the influence of the pressure pulse in the turbine. Additionally, PIV technique was used to investigate flow velocity in the draft tube. In the numerical simulation, different sets of operating points were selected to get performance characteristics of the turbine and best efficiency point indicated 91.67% efficiency at 0.02m3/s, power output 3.32kW. For misaligned guide vanes, more options can be tried out by misaligning more guide vanes, at higher angles. Additionally, based on the numerical analysis of a Francis turbine, the results for efficiency obtained from simulation are found to good agreement with the model results obtained from the manufacturer. From the performed experiment on performance test of Francis turbine using the Francis turbine experimental set-up in the Flow Informatics Laboratory at Korean Maritime and Ocean University. The experimental analysis of the turbine showed a significant result. The turbine operated at different vane angle setting were obtained and tested by varying the parameters as a guide vane angle in the 6 different range of between 2-12 degrees, speed, and 500-1700 rpm respectively. The lowest difference between the experimental and numerical results was 2.03% and the maximum difference between the experimental and numerical results was 6.12 %. Numerical efficiency higher than experimental efficiency.CHAPTER 1. INTRODUCTION 1 1.1 Background 1 1.2 History of hydropower 2 1.3 Classification of the hydropower plant 3 1.3.1 River Power Plant (Run-Of-River) 4 1.3.2 Pumped storage hydropower plant 5 1.3.3 Reservoir hydropower plant 5 1.3.4 Instream technology using existing facilties 6 1.4 Organization of hydropower plant 6 CHAPTER 2. HYDRO TURBINES 8 2.1 Classification of turbine 8 2.1.1 Based on head and quantity of water available 8 2.1.2 Classification based on action of the water flowing through runner 9 2.1.3 Classification based on Direction of flow of water in runner 10 2.1.4 Classification based on specific speed 10 2.2 Francis turbine 12 2.2.1 Components of the Francis turbine 12 2.2.2 Spiral Casing 13 2.2.3 Runner 13 2.2.4 Guide vanes and stay vanes 14 2.2.5 Draft tube 14 2.3 Cavitation in francis turbine 19 CHAPTER 3. PERFORMANCE AND DESIGN OPTIMIZATION OF SETUP TURBINE 22 3.1 Modeling 22 3.2 Numerical analysis 28 3.2.1 Computational fluid dynamics (CFD) 28 3.2.2 Grid discretization 29 3.2.3 Boundary condition 31 3.2.4 Hydraulic efficiency and power characteristic 32 3.2.5 Flow feature and pressure distribution 34 3.3 Unsteady flow analysis 41 3.3.1 Unsteady flow at full load 41 3.3.2 Unsteady flow at partial load 45 3.3.3 A draft tube swirl 46 3.3.4 Vortex rope in part flow 46 3.4 Signal analysis 52 3.5 Misaligned guide vane 55 CHAPTER 4. EXPERIMENTAL ANALYSIS 58 4.1 Eexperimental setup 58 4.2 Experimental apparatus specifications 60 4.2.1 Torque Transducer 60 4.2.2 Powder brake 62 4.2.3 Pressure transducers 63 4.2.4 Flow mmeter 64 4.3 Calibration and uncertainty analysis 66 4.4 Eexperimental procedure 67 4.4.1 Starting the Pump 67 4.4.2 Starting the Francis turbine 67 4.4.3 Hydraulic efficiency of experimental 67 4.5 PIV experiment 70 4.5.1 Overview of PIV Flow Visualization 70 4.5.2 Configuration of PIV experiment device 71 4.5.3 Lighting and tracking particles 73 4.5.4 Result of the PIV experiment 75 CHAPTER 5. CONCLUSION 82 Acknowledgement 83 References 84Maste

    Dynamic safety assessment of a nonlinear pumped-storage generating system in a transient process

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    This paper focuses on a pumped-storage generating system with a reversible Francis turbine and presents an innovative framework for safety assessment in an attempt to overcome their limitations. Thus the aim is to analyze the dynamic safety process and risk probability of the above nonlinear generating system. This study is carried out based on an existing pumped-storage power station. In this paper we show the dynamic safety evaluation process and risk probability of the nonlinear generating system using Fisher discriminant method. A comparison analysis for the safety assessment is performed between two different closing laws, namely the separate mode only to include a guide vane and the linkage mode that includes a guide vane and a ball valve. We find that the most unfavorable condition of the generating system occurs in the final stage of the load rejection transient process. It is also demonstrated that there is no risk to the generating system with the linkage mode but the risk probability of the separate mode is 6 percent. The results obtained are in good agreement with the actual operation of hydropower stations. The developed framework may not only be adopted for the applications of the pumped-storage generating system with a reversible Francis turbine but serves as the basis for the safety assessment of various engineering applications.National Natural Science Foundation of ChinaFundamental Research Funds for the Central UniversitiesScientific research funds of Northwest A&F UniversityScience Fund for Excellent Young Scholars from Northwest A&F University and Shaanxi Nova progra
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