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Статті в журналах з теми "Hydraulic turbines Models"
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Shi, Feng Xia, Jun Hu Yang, and Xiao Hui Wang. "Effect of Rotating Speed on Hydraulic Energy Recovery Turbines Performance." Applied Mechanics and Materials 444-445 (October 2013): 1033–37. http://dx.doi.org/10.4028/www.scientific.net/amm.444-445.1033.
Повний текст джерелаАнотація:
In order to forecast the rotating speed of the hydraulic energy recovery turbine, Single centrifugal pump and single centrifugal pump with guide vane in reverse operation were adopted as turbines. 3D models were founded by pro/E software for turbines, Then the models were meshed by gambit and Simulated by fluent6.3 software. It was shown that before the best efficiency points, The higher the rotating speed, the lower the efficiency of turbine . but after the best efficiency points, the efficiency of turbine increased with the rise of rotating speed. with the rise of rotating speed ,the pressure in runner inlet was added, the amplitude of pressure pulse was added. the pressure distribution in runner inlet was more even of model B than that of model A. With a guide vane ,The steady scope of rotating speed in hydraulic energy recovery turbine was diminished,and the Controllability of rotating speed in hydraulic energy recovery turbines can be improved by guide vane. Some theories were offered for hydraulic energy recovery turbine researches.
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Zharkovskiy, A. A., V. A. Shchur, M. Omran, and A. A. Staseyev. "Automation of the design of the impeller of a radial-axial hydraulic turbine." Izvestiya MGTU MAMI 15, no. 4 (December 15, 2021): 18–26. http://dx.doi.org/10.31992/2074-0530-2021-50-4-18-26.
Повний текст джерелаАнотація:
The article describes approaches to the design of a vane system of radial-axial hydraulic turbines based on an automated design system developed at SPbPU using the Python programming language. The specified system currently includes the following modules: selection of the main parameters of the hydraulic turbine, construction of the meridional projection of the impeller, calculation of the potential flow and construction of the blade system of the radial-axial hydraulic turbine. The choice of the main parameters of the hydraulic turbine is based on the technique generally accepted in hydraulic turbine engineering, which has been digitized and introduced into the software package. The paper considers and analyzes different approaches to the design of the meridional bypasses of the flow path in the area of the impeller of a radial-axial hydraulic turbine, a comparison of the results of their construction using different methods is given. A technique that is most suitable for algorithmization in the software package based on the results of the analysis was selected. The construction of streamlines and the calculation of velocities along them are presented on the basis of the calculation of the potential flow in the meridian section. The design of the blade system of the hydraulic turbine was carried out by the method of solving the direct axisymmetric problem of the theory of hydraulic machines. As an example, a blade system of a radial-axial hydraulic turbine was designed for a head up to 75 meters, the initial parameters of which correspond to hydraulic turbines-analogues of similar speed. The designed hydro turbine was calculated in Ansys, and the results confirmed its excellent energy properties. It is planned to further develop the software package in terms of automatic construction of 3-dimensional solid models of the flow path, which can later be calculated by the methods of computational fluid dynamics and optimized to obtain hydraulic turbines with parameters corresponding to the current state of the art.
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Ayancik, Fatma, Erdem Acar, Kutay Celebioglu, and Selin Aradag. "Simulation-based design and optimization of Francis turbine runners by using multiple types of metamodels." Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 231, no. 8 (June 29, 2016): 1427–44. http://dx.doi.org/10.1177/0954406216658078.
Повний текст джерелаАнотація:
In recent years, optimization started to become popular in several engineering disciplines such as aerospace, automotive and turbomachinery. Optimization is also a powerful tool in hydraulic turbine industry to find the best performance of turbines and their sub-elements. However, direct application of the optimization techniques in design of hydraulic turbines is impractical due to the requirement of performing computationally expensive analysis of turbines many times during optimization. Metamodels (or surrogate models) that can provide fast response predictions and mimic the behavior of nonlinear simulation models provide a remedy. In this study, simulation-based design of Francis type turbine runner is performed by following a metamodel-based optimization approach that uses multiple types of metamodels. A previously developed computational fluid dynamics-based methodology is integrated to the optimization process, and the results are compared to the results obtained from on-going computational fluid dynamics studies. The results show that, compared to the conventional methods such as computational fluid dynamics-based methods, metamodel-based optimization can shorten the design process time by a factor of 9.2. In addition, with the help of optimization, turbine performance is increased while cavitation on the turbine blades, which can be harmful for the turbine and reduce its lifespan, is reduced.
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Martineau Rousseau, Philippe, Azzeddine Soulaïmani, and Michel Sabourin. "Efficiency Assessment for Rehabilitated Francis Turbines Using URANS Simulations." Water 13, no. 14 (July 7, 2021): 1883. http://dx.doi.org/10.3390/w13141883.
Повний текст джерелаАнотація:
Due to the large number of aging hydraulic turbines in North America, rehabilitation is a growing market as these turbines have low efficiency compared to modern ones. Computational Fluid Dynamics identifies components with poor hydraulic performance. The models often used in industry are based on individually analyzing the sub-components of a turbine instead of full turbine simulations due to computational and time limitations. An industrial case has shown that such analyses may lead to underestimating the efficiency increases by modifying the stay vane. The unsteady full turbine simulation proposes to simulate all components simultaneously to assess this efficiency augmentation due to stay vane rehabilitation. The developed simulation methodology is used to evaluate the efficiency increase and the flow of two rehabilitated turbines with stay vane modifications. Comparison with model tests shows the accuracy of the simulations. However, the methodology used shows imprecision in predicting the efficiency increase compared to model tests. Further works should consider the use of more complex flow modeling methods to measure the efficiency increase by the stay vane modifications.
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Seifollahi Moghadam, Zahra, François Guibault, and André Garon. "On the Evaluation of Mesh Resolution for Large-Eddy Simulation of Internal Flows Using Openfoam." Fluids 6, no. 1 (January 5, 2021): 24. http://dx.doi.org/10.3390/fluids6010024.
Повний текст джерелаАнотація:
The central aim of this paper is to use OpenFOAM for the assessment of mesh resolution requirements for large-eddy simulation (LES) of flows similar to the ones which occur inside the draft-tube of hydraulic turbines at off-design operating conditions. The importance of this study is related to the fact that hydraulic turbines often need to be operated over an extended range of operating conditions, which makes the investigation of fluctuating stresses crucial. Scale-resolving simulation (SRS) approaches, such as LES and detached-eddy simulation (DES), have received more interests in the recent decade for understanding and mitigating unsteady operational behavior of hydro turbines. This interest is due to their ability to resolve a larger part of turbulent flows. However, verification studies in LES are very challenging, since errors in numerical discretization, but also subgrid-scale (SGS) models, are both influenced by grid resolution. A comprehensive examination of the literature shows that SRS for different operating conditions of hydraulic turbines is still quite limited and that there is no consensus on mesh resolution requirement for SRS studies. Therefore, the goal of this research is to develop a reliable framework for the validation and verification of SRS, especially LES, so that it can be applied for the investigation of flow phenomena inside hydraulic turbine draft-tube and runner at their off-design operating conditions. Two academic test cases are considered in this research, a turbulent channel flow and a case of sudden expansion. The sudden expansion test case resembles the flow inside the draft-tube of hydraulic turbines at part load. In this study, we concentrate on these academic test cases, but it is expected that hydraulic turbine flow simulations will eventually benefit from the results of the current research. The results show that two-point autocorrelation is more sensitive to mesh resolution than energy spectra. In addition, for the case of sudden expansion, the mesh resolution has a tremendous effect on the results, and, so far, we have not capture an asymptotic converging behavior in the results of Root Mean Square (RMS) of velocity fluctuations and two-point autocorrelation. This case, which represents complex flow behavior, needs further mesh resolution studies.
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Skripkin, Sergey, Mikhail Tsoy, and Sergey Shtork. "Experimental Investigation Of Double Precessing Vortex Rope Forming In Draft Tube Models." Siberian Journal of Physics 10, no. 2 (June 1, 2015): 73–82. http://dx.doi.org/10.54362/1818-7919-2015-10-2-73-82.
Повний текст джерелаАнотація:
This work is devoted to the experimental research of the flow structure in draft tube models of hydro turbines. Precessing vortex core was formed using fixed swirler in a flow such as observed in natural hydro turbines under off-design conditions. In laboratory conditions it has been able to find the effect of the transition between single- and double- vortex rope. Their frequency characteristics have been measured in the range of Reynolds numbers 5·104 –5·105 . Based on the analysis of data high-speed shooting the mechanism of complete transition between single and double vortex modes was investigated in detail. The investigation of this phenomenon is of particular interest for the design and operation of hydraulic turbine equipment due to off-design pressure pulsations with sudden changes in frequency and amplitude in a flow occurring.
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Šiško Kuliš, Marija, Nikola Mijalić, and Senad Hidžić. "Cavitation Detection on Hydraulic Machines." Journal of Energy - Energija 70, no. 3 (August 16, 2022): 25–32. http://dx.doi.org/10.37798/202170328.
Повний текст джерелаАнотація:
This paper gives an engineering review of the phenomenon of cavitation on hydraulic machines: turbines, pumps and ships propellers. The types of cavitation and its consequences are presented by the cabinet study of the results of relevant researches on models and real plants. In the special focus of this paper are the techniques of exploration of cavitation erosion: visual examination, measurements of pressures and vibrations and CFD methods.
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McKinnon, Conor, James Carroll, Alasdair McDonald, Sofia Koukoura, and Charlie Plumley. "Investigation of Isolation Forest for Wind Turbine Pitch System Condition Monitoring Using SCADA Data." Energies 14, no. 20 (October 13, 2021): 6601. http://dx.doi.org/10.3390/en14206601.
Повний текст джерелаАнотація:
Wind turbine pitch system condition monitoring is an active area of research, and this paper investigates the use of the Isolation Forest Machine Learning model and Supervisory Control and Data Acquisition system data for this task. This paper examines two case studies, turbines with hydraulic or electric pitch systems, and uses an Isolation Forest to predict failure ahead of time. This novel technique compared several models per turbine, each trained on a different number of months of data. An anomaly proportion for three different time-series window lengths was compared, to observe trends and peaks before failure. The two cases were compared, and it was found that this technique could detect abnormal activity roughly 12 to 18 months before failure for both the hydraulic and electric pitch systems for all unhealthy turbines, and a trend upwards in anomalies could be found in the immediate run up to failure. These peaks in anomalous behaviour could indicate a future failure and this would allow for on-site maintenance to be scheduled. Therefore, this method could improve scheduling planned maintenance activity for pitch systems, regardless of the pitch system employed.
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McKinnon, Conor, James Carroll, Alasdair McDonald, Sofia Koukoura, and Charlie Plumley. "Investigation of Isolation Forest for Wind Turbine Pitch System Condition Monitoring Using SCADA Data." Energies 14, no. 20 (October 13, 2021): 6601. http://dx.doi.org/10.3390/en14206601.
Повний текст джерелаАнотація:
Wind turbine pitch system condition monitoring is an active area of research, and this paper investigates the use of the Isolation Forest Machine Learning model and Supervisory Control and Data Acquisition system data for this task. This paper examines two case studies, turbines with hydraulic or electric pitch systems, and uses an Isolation Forest to predict failure ahead of time. This novel technique compared several models per turbine, each trained on a different number of months of data. An anomaly proportion for three different time-series window lengths was compared, to observe trends and peaks before failure. The two cases were compared, and it was found that this technique could detect abnormal activity roughly 12 to 18 months before failure for both the hydraulic and electric pitch systems for all unhealthy turbines, and a trend upwards in anomalies could be found in the immediate run up to failure. These peaks in anomalous behaviour could indicate a future failure and this would allow for on-site maintenance to be scheduled. Therefore, this method could improve scheduling planned maintenance activity for pitch systems, regardless of the pitch system employed.
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Purece, Cristian, Vasile Pleşca, and Lilica Corlan. "Technologies for obtaining energy from micro-hydropower resources." Technium: Romanian Journal of Applied Sciences and Technology 2, no. 4 (June 16, 2020): 124–33. http://dx.doi.org/10.47577/technium.v2i4.837.
Повний текст джерелаАнотація:
Currently the global demand for electricity and drinking water is constantly increasing. Given its many economic, social and environmental benefits, hydro energy will be an important contributor to the energy mix of the future. Isolated areas, heavily underdeveloped regions, disaster-affected areas have a common need of easy-to-use means to generate electricity. The most efficient way to meet these needs involves the use of various renewable energy resources available locally. One of the main sources of renewable energy is hydro energy, more specifically micro-hydro energy. However, hydropower projects involve various considerations at different levels of project implementation. To make the most of the available hydropower potential, new models of hydraulic turbines were developed. For a cost-effective and efficient hydropower project, the selection of the hydraulic turbine must be optimally studied. The objective of the present work is to carry out a review of the optimum selection mode of the hydraulic turbine that equips a micro hydropower plant (MHP).
Дисертації з теми "Hydraulic turbines Models"
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Daniel, Gregory Bregion 1984. "Desenvolvimento de um modelo termohidrodinâmico para análise em mancais segmentados." [s.n.], 2012. http://repositorio.unicamp.br/jspui/handle/REPOSIP/263817.
Повний текст джерелаАнотація:
Orientador: Katia Lucchesi CavalcaTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica
Made available in DSpace on 2018-08-20T21:45:12Z (GMT). No. of bitstreams: 1 Daniel_GregoryBregion_D.pdf: 5439822 bytes, checksum: 616b0f86a01472d86d7a1b9dc7943ea0 (MD5) Previous issue date: 2012
Resumo: Este trabalho tem por objetivo analisar o comportamento termohidrodinâmico de mancais hidrodinâmicos segmentados e avaliar a influência da temperatura nas características dinâmicas (coeficiente equivalente de rigidez e de amortecimento) desses mancais. Por esse motivo, foi desenvolvido um modelo termohidrodinâmico para análise em mancais segmentados, permitindo assim determinar a distribuição de pressão no filme lubrificante juntamente com a distribuição de temperatura. O método de volumes finitos é utilizado na discretização do modelo termohidrodinâmico desenvolvido para resolução da equação de Reynolds e da equação de energia. A partir da distribuição de pressão e de temperatura no filme lubrificante do mancal pode-se calcular as forças hidrodinâmicas atuantes no mancal, a posição de equilíbrio do eixo no mancal e, consequentemente, os coeficientes equivalentes de rigidez e de amortecimento. Os resultados obtidos através do modelo termohidrodinâmico (THD) foram então comparados com os resultados obtidos através do modelo hidrodinâmico clássico (HD), em que o filme lubrificante é considerando isoviscoso, possibilitando analisar a influência da variação da temperatura do filme lubrificante na determinação dos coeficientes equivalentes de rigidez e de amortecimento do mancal. A validação experimental do modelo termohidrodinâmico desenvolvido é realizada a partir de dados de temperatura obtidos em um mancal hidrodinâmico segmentado operando em uma turbina a vapor. Os resultados apresentados neste trabalho mostram as distribuições de pressão, as distribuições de temperatura, a posição de equilíbrio do eixo e dos segmentos do mancal, as forças hidrodinâmicas no mancal, os coeficientes equivalentes de rigidez e de amortecimento na forma completa e na forma reduzida (síncrono e não síncrono), o que permite realizar uma análise das condições de lubrificação e do comportamento dinâmico de mancais hidrodinâmicos segmentados
Abstract: This work aims to analyze the thermohydrodynamic behavior of tilting pad journal bearings and evaluate the temperature influence on the dynamics characteristics (equivalent stiffness and damping coefficients) of these bearings. For this reason, a thermohydrodynamic model was developed to analyze tilting pad journal bearings, leading to the evaluation of the pressure distribution in the oil film jointly with the temperature distribution. The Finite Volume Method is applied in this thermohydrodynamic model to solve the Reynolds' Equation and the Energy Equation. From the distributions of pressure and temperature in the oil film, it is possible to determine the hydrodynamic forces on the bearing, the equilibrium position of the shaft in the bearing and, consequently, the equivalent stiffness and damping coefficients. The results obtained through the thermohydrodynamic model (THD) were compared with the results obtained through the hydrodynamic model (HD), in which the oil film is considered isoviscous, what enables the analysis of the influence of the temperature variation of the oil film in the determination of the equivalent stiffness and damping coefficients of the bearing. The experimental validation of the developed thermohydrodynamic model was accomplished using the temperature measurements obtained in a tilting pad journal bearing operating in a steam turbine. The results presented in this work show the pressure distribution, the temperature distribution, the equilibrium position of the shaft and the pads in the bearing, the hydrodynamic forces in the bearing and the equivalent stiffness and damping coefficients in the full and reduced form (synchronous and non-synchronous), bringing to the analysis of the lubrication condition and the dynamic behavior of tilting pad journal bearing
Doutorado
Mecanica dos Sólidos e Projeto Mecanico
Doutor em Engenharia Mecânica
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Marjavaara, Daniel. "CFD driven optimization of hydraulic turbine draft tubes using surrogate models." Doctoral thesis, Luleå : Division of Fluid Mechanics, Luleå University of Technology, 2006. http://epubl.ltu.se/1402-1544/2006/41/.
Повний текст джерела
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Houde, Sébastien. "Analysis of the part-load and speed-no-load flow dynamics in a model propeller hydraulic turbine." Doctoral thesis, Université Laval, 2018. http://hdl.handle.net/20.500.11794/29823.
Повний текст джерелаАнотація:
Les turbines hydrauliques sont devenues un atout important pour la régulation de la puissance sur les réseaux électriques. Cependant, les scénarios de régulation de puissance exigent que les turbines fonctionnent loin de leurs points d'opération optimale, dans des régions où de grandes uctuations de pression peuvent affecter l'intégrité structurale de la turbine. Cette thèse présente des contributions a l'etude de l'hydrodynamique de l'écoulement dans une turbine helice modele fonctionnant dans des conditions de charge partielle et de vitesse-sans-charge. À charge partielle, les fluctuations de pression principales sont associées à un vortex cavitant. Des mesures provenant de Vélocimétrie par Imagerie de Particules (PIV) couplées à des techniques de fluorescence induite par laser et d'ombroscopie ont été utilisées pour reconstruire l'interface eau-vapeur et identier l'origine de fluctuations aectant la précision des mesures de PIV moyennées en phase. De plus, des capteurs de pression miniatures incorporés dans deux aubes de la roue ainsi que des jauges de deformation montées sur les aubes ont fourni des données pour quantier l'impact du vortex de charge partielle sur la turbine. Cette thèse présente également l'une des premieres etudes detaillees sur les conditions transitoires et sans charge dans une turbine modèle. Les capteurs de pression et de déformation sur les aubes ont ete utilisés pour identier les instabilités dominantes dans des conditions de vitesse sans charge et d'emballement. Des simulations basées sur la technologie Scale Adaptive Simulations (SAS) de la condition de vitesse-sans-charge ont été utilisés pour étudier un décrochage tournant dans la roue. Des simulations sans les aubes indiquent que le décrochage tournant est associé à une couche cisaillée provenant d'une recirculation autour du moyeu de la roue et d'une séparation de la couche limite sur le fond supérieur.Hydraulic turbines have become an important asset to provide power regulation on electrical grids. However, power-regulation scenarios require turbines to operate far from their best eciency conditions, in regions where large pressure uctuations aect the turbine structural integrity. This is particularly acute for xed blade reaction turbines such as propeller units. This thesis presents contributions to the study of the hydrodynamics of the ow in a model propeller turbine operating in part-load and speed-no-load conditions. In part load, the main pressure uctuations are associated with the part-load vortex. Data from Particle Image Velocimetry (PIV), coupled to Laser Induced Fluorescence and shadowgraphy techniques, were used to reconstruct the water-vapour interface and to identify the origin of uctuations aecting the precision of the phase-averaged PIV measurements. Furthermore, miniature pressure transducers imbedded in two runner blades and strain gages at the blade roots provided data to quantify the impact of the part load vortex on the runner. This thesis also presents one of the rst detailed studies on transient and no-load conditions in a model hydro-turbine. Pressure and strain sensors were used to identify the dominant ow instabilities in speed-no-load and runaway conditions. Scale Adaptive Simulations (SAS) of the speed-no-load condition were used to study a rotating stall dominating the runner ow. Simulations without runner blades indicate that the rotating stall is associated with an unstable shear-layer originating from a recirculation around the runner hub and a boundary layer separation on the turbine head cover. Those results open the possibility of eventually developing mitigation techniques.
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Massé, Alexandre. "Experiments and numerical simulations of the flow within a model of a hydraulic turbine surge chamber." Thesis, McGill University, 2011. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=96962.
Повний текст джерелаАнотація:
Surge chambers are sometimes included in the hydraulic circuits of hydroelectric power plants as a means of absorbing pressure waves formed by the opening/closing of a turbine. Surge chambers, however, result in additional power loss and therefore reduce the efficiency of the plant. This work aims to 1) investigate the physical phenomena and flow within a surge chamber under normal operation (i.e. no opening/closing of a turbine), and 2) obtain experimental data for the validation of numerical simulations of this complex flow.Experiments and numerical simulations have been conducted for a simplified model of a surge chamber operated under multiple configurations at a constant input flow rate. This 3-D, unsteady, incompressible, swirling, two-phase flow has been experimentally characterized by global values, such as head losses, and local values, such as free-surface profiles, free-surface oscillations, reduced pressure profiles and velocity fields. The same quantities were also obtained numerically using the "rasInterFoam" solver of the open source code "OpenFOAM-1.5," for incompressible two-phase flows. This solver implements a one-fluid, volume-of-fluid (VOF) method with an interface-capturing scheme. Overall agreement between the experimental and numerical quantities is good, although there are local discrepancies. The periodic oscillations of the flow observed in the experiments and the numerical simulations of the simplified model (operated under constant input flow rate) were associated with the phenomena of i) oscillating mass, and ii) self-induced sloshing.Des chambres d'équilibre sont parfois intégrées aux circuits hydrauliques des centrales hydroélectriques afin d'absorber les ondes de pression se formant lors de l'ouverture/fermeture d'une turbine. Celles-ci affectent l'efficacité des centrales, en augmentant les pertes d'énergie. Ce projet de maîtrise vise à 1) étudier les phénomènes physiques ainsi que l'écoulement à l'intérieur d'une chambre d'équilibre sous opération normale (i.e. aucune ouverture/fermeture de turbine), et à 2) obtenir des données expérimentales visant à valider les simulations numériques de cet écoulement complexe.Les mesures expérimentales et les simulations numériques ont été effectuées sur un modèle simplifié d'une chambre d'équilibre. Ce dernier a été opéré sous de multiples configurations à débit d'entrée constant. L'écoulement tridimensionnel, instationnaire, incompressible, tourbillonnant et biphasique a été caractérisé expérimentalement par des quantités globales, telles que des pertes de charges, ainsi que par des quantités locales, telles que des profils et des périodes d'oscillations de surface libre, des profils de pression réduite et des champs de vitesses. Les mêmes quantités ont aussi été obtenues par calculs numériques en utilisant l'exécutable "rasInterFoam" du code à source ouverte "OpenFOAM-1.5", limité aux écoulements incompressibles et biphasiques. Ce dernier traite l'écoulement comme étant un mélange localement homogène composé de deux phases en utilisant une méthode "volume-of-fluid" (VOF) et un schéma de capture d'interface.Globalement, les résultats numériques concordent avec les mesures expérimentales, malgré quelques variations locales. Les oscillations périodiques de l'écoulement survenant à un débit d'entrée constant, qui ont été observées tant sur le banc d'essai que dans les simulations numériques, sont associées aux phénomènes i) d'oscillation de masse et de ii) ballottement auto-induit.
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Le, Grange Willie. "Component development for a high fidelity transient simulation of a coal-fired power plant using Flownex SE." Master's thesis, University of Cape Town, 2018. http://hdl.handle.net/11427/29863.
Повний текст джерелаАнотація:
Large coal-fired power stations are designed to be run predominantly at full load and optimum conditions. The behaviour of plants, operating at low load and varying conditions, is getting more and more attention due to the introduction of variable renewable generation on the grid. Consequently, the need for a fully transient high-fidelity system based model has grown, as this will enable one to study the behaviour of plants under such non-ideal conditions. This report details the development of a feedwater heater, deaerator and turbine component for such a high-fidelity transient system model using the Flownex Simulation Environment, a onedimensional thermohydraulic network solver. The components have been modelled all with the aim of using minimal design input data. The feedwater heater component model includes transient effects and thermodynamic relations to represent aspects such as heater performance, level control and transient inertia. In determining the heat transfer characteristics, the model makes use of plant-performance data and correlates the amount of heat transfer by using the feedwater mass flow as the load indicating parameter. This approach eliminates the need for specific geometrical details to calculate the effective heat transfer area. The level control is modelled by using a level representation built from using heat exchanger design methods. The turbine component is modelled by using Fuls’ Semi-Ellipse law or the pressure drop modelling and Ray’s semi-empirical method for the efficiency modelling. The model also contains transient effects, which include thermal inertia due to the shaft and casing, and rotational inertia due to the shaft. The deaerator component is modelled by adapting the model presented by Banda, and modifying the model to work under various conditions. This involved using curve fit methods in Flownex to use input data to model the pressure drop over the main condensate valve. Each of the mentioned components was validated and verified with plant data and finally packaged into a compound component which is a component consisting of a subnetwork in Flownex. These compound components further contain design inputs which are easily accessible by the user. The component models were integrated into larger networks in which various scenarios can be run. A short transient scenario was run on the low-pressure feedwater train of a specific power station. The scenario involved a turbine trip where the bled steam valves for the heaters were closed suddenly. The speed of the valves closing was however unknown and after closing the valves in approximately 10 seconds, results agreed relatively well with plant data. This illustrated the short transient capabilities of the feedwater heater component model. The three component models (feedwater heater, turbine and deaerator) were finally integrated into a regenerative Rankine cycle and was set up using minimal design data. The boiler, condenser and condensate pump were set as boundary conditions in the network but all extraction points for the network were connected. Steady-state results were obtained for various load cases and the main temperature, flow and pressure results were compared. Results agree well with plant data, even at low load conditions
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Greco, Francesca. "Design of an innovative wind pile for water desalination." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2018.
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L’aumento dei consumi e i mutamenti climatici in atto stanno prosciugando le risorse del pianeta, tra cui le riserve di acqua dolce. Tuttavia, un potenziale enorme è rappresentato dagli oceani, che costituiscono il 97% dell’acqua che ricopre il nostro pianeta. La desalinizzazione dell’acqua di mare è un sistema già diffuso ma, ad oggi, la maggior parte degli impianti sono alimentati da fonti di energia non rinnovabili. Il passaggio a una produzione di acqua dolce sostenibile, seppur necessario, è ancora in fase iniziale.
La dissalazione con membrane a osmosi inversa prevede il pompaggio di acqua salata attraverso una membrana semipermeabile, che lascia passare le molecole di acqua e trattiene i sali disciolti.
Nella presente tesi, la pressurizzazione dell’acqua di mare che alimenta il processo di osmosi inversa avviene per mezzo di turbine eoliche a trasmissione idraulica. Rispetto alle convenzionali turbine eoliche, il classico sistema di trasmissione di potenza nella carlinga è sostituito da una pompa ad acqua a pistone radiale ed una linea idraulica.
Tra le sfide che questa soluzione presenta, conciliare la necessità del processo di osmosi inversa di avere un input costante con la variabilità e imprevedibilità della risorsa eolica è una delle maggiori.
Lo scopo di questa tesi è stato quello di analizzare il comportamento dinamico di membrane a osmosi inversa quando usate in combinazione con una turbina a trasmissione idraulica, per mezzo dello sviluppo di un modello numerico, e confrontare i risultati ottenuti con quelli di una turbina eolica convenzionale. Parallelamente, una possibile applicazione è stata individuata nell’Isola di Pantelleria, i cui dati anemometrici sono stati utilizzati per generare gli input per il modello numerico.
Seppur con varie semplificazioni, grazie al modello sviluppato è stato possibile effettuare un primo design per i principali componenti del sistema e simulare la produzione di acqua annuale per l’isola di Pantelleria.
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Рєзва, Ксенія Сергіївна. "Удосконалення проточних частин високонапірних оборотних гідромашин на основі чисельного моделювання їх гідродинамічних характеристик". Thesis, Національний технічний університет "Харківський політехнічний інститут", 2019. http://repository.kpi.kharkov.ua/handle/KhPI-Press/40009.
Повний текст джерелаАнотація:
Дисертація на здобуття наукового ступеня кандидата технічних наук за спеціальністю 05.05.17 – гідравлічні машини і гідропневмоагрегати. – Національний технічний університет "Харківський політехнічний інститут", Харків, 2019 р.
Дисертацію присвячено вирішенню науково-практичної задачі удосконалення проточних частин високонапірних оборотних гідромашин за рахунок розробки методів розрахунку та аналізу їх гідродинамічних характеристик. На підставі розгляду тенденцій розвитку гідроенергетики України, з урахуванням ролі високонапірних оборотних гідромашин в об'єднаній енергетичній системі, відмічено актуальність проектування нових проточних частин. Визначено переваги та недоліки існуючих методів дослідження гідродинамічних процесів у проточних частинах оборотних гідромашин. Наведені результати розрахунку гідродинамічних характеристик елементів проточної частини на основі методу осереднених безрозмірних параметрів для оборотних гідромашин ОРО200-В-100 та ОРО500-В-100. Застосована математична модель робочого процесу гідромашини на основі блочно-ієрархічного підходу для проведення дослідження балансу енергії. Визначено вплив геометричних параметрів елементів проточної частини на показники роботи. Проведено чисельне дослідження просторової течії рідини в проточній частині високонапірних оборотних гідромашин за допомогою CFD, що дозволило визначити та візуалізувати картину течії. Складено баланси енергії гідромашин ОРО200-В-100 та ОРО500-В-100. Відмічено, що розподіл втрат по елементам проточної частини нерівномірний: для ОРО200-В-100 найбільшу частину втрат складають втрати в робочому колесі (близько 56 %), для ОРО500-В-100 – втрати у підводі (близько 62 %). Описано основні положення визначення оптимального режиму роботи оборотної гідромашини. Запропоновано та досліджено модифікований підвід для тихохідної оборотної гідромашини ОРО500-В-100, щоб підвищити її енергетичні показники: краще узгоджені елементи ПЧ та гідравлічний ККД збільшився на 2 %.Thesis for granting the Degree of Candidate of Technical sciences in speciality 05.05.17 – Hydraulic machines and hydropneumatic units. – National Technical University "Kharkiv Polytechnic Institute", 2019. The tеhesis is devoted to the solution of the scientific and practical problem of improvement of the water passages of the high-pressure reversible hydraulic due to calculation and analysis their hydrodynamic characteristics. Based on the review of the trends in the development of hydropower engineering in Ukraine and given the role of high-pressure reversible hydraulic machines in the United Power System, it was noted that the designing a new flow parts is topical task. Advantages and disadvantages of the existing methods for research hydrodynamic processes in water passages of reversible hydraulic machines were identified after their analysis. The results of the calculation of the hydrodynamic characteristics of the elements of the water passages based on the method of averaged dimensionless parameters using the example of reversible hydraulic machines OPO200-B-100 and OPO500-B-100 were demonstrated. The mathematical model of the hydraulic machine working process based on a block-hierarchical approach was used to study the energy balance in the turbine and pump modes of hydraulic machines. The influence of the geometrical parameters of the elements of the water passage on the performance was determined: how the angle of flow in the spiral casing (cп ), the height of the wicket gate (b0 D) and the shape of the wicket gate profile influence the value of the coefficient resistance in the wicket gate. A numerical study of the three-dimensional flow of fluid in the water passage of high-pressure reversible hydraulic machines was carried out using the CFD software. This program allows determining the character of the flow and presenting the fields of distribution of velocity components, pressure and streamlines. The balances of energy were compiled: for the OPO200-B-100 in the turbine and pump operation modes, for the OPO500-B-100 in the turbine operation mode. It is noted that the distribution of losses on the elements of the water passage is not uniform: for the OPO200-B-100, the greatest part of the total losses are losses in the runner (about 56%), for OPO500-B-100 - losses in the inlet (about 62%). The main points for determining the optimal operating mode of the reversible hydraulic machine are described. The modified inlet for low-speed high-pressure hydraulic machine OPO500-B-100 was proposed and investigated to increase energy performance of hydraulic machine. The spiral casing was expanded, the number of stay vane blades and wicket gate blades were reduced to 16. As a result of the calculations of the modified inlet, the obtained results showed that the second variant made it possible to better align the elements of the water passage and the hydraulic efficiency increased by 2 %.
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Рєзва, Ксенія Сергіївна. "Удосконалення проточних частин високонапірних оборотних гідромашин на основі чисельного моделювання їх гідродинамічних характеристик". Thesis, Національний технічний університет "Харківський політехнічний інститут", 2018. http://repository.kpi.kharkov.ua/handle/KhPI-Press/40011.
Повний текст джерелаАнотація:
Дисертація на здобуття наукового ступеня кандидата технічних наук за спеціальністю 05.05.17 – гідравлічні машини і гідропневмоагрегати. – Національний технічний університет "Харківський політехнічний інститут", Харків, 2019 р.
Дисертацію присвячено вирішенню науково-практичної задачі удосконалення проточних частин високонапірних оборотних гідромашин за рахунок розробки методів розрахунку та аналізу їх гідродинамічних характеристик. На підставі розгляду тенденцій розвитку гідроенергетики України, з урахуванням ролі високонапірних оборотних гідромашин в об'єднаній енергетичній системі, відмічено актуальність проектування нових проточних частин. Визначено переваги та недоліки існуючих методів дослідження гідродинамічних процесів у проточних частинах оборотних гідромашин. Наведені результати розрахунку гідродинамічних характеристик елементів проточної частини на основі методу осереднених безрозмірних параметрів для оборотних гідромашин ОРО200-В-100 та ОРО500-В-100. Застосована математична модель робочого процесу гідромашини на основі блочно-ієрархічного підходу для проведення дослідження балансу енергії. Визначено вплив геометричних параметрів елементів проточної частини на показники роботи. Проведено чисельне дослідження просторової течії рідини в проточній частині високонапірних оборотних гідромашин за допомогою CFD, що дозволило визначити та візуалізувати картину течії. Складено баланси енергії гідромашин ОРО200-В-100 та ОРО500-В-100. Відмічено, що розподіл втрат по елементам проточної частини нерівномірний: для ОРО200-В-100 найбільшу частину втрат складають втрати в робочому колесі (близько 56 %), для ОРО500-В-100 – втрати у підводі (близько 62 %). Описано основні положення визначення оптимального режиму роботи оборотної гідромашини. Запропоновано та досліджено модифікований підвід для тихохідної оборотної гідромашини ОРО500-В-100, щоб підвищити її енергетичні показники: краще узгоджені елементи ПЧ та гідравлічний ККД збільшився на 2 %.Thesis for granting the Degree of Candidate of Technical sciences in speciality 05.05.17 – Hydraulic machines and hydropneumatic units. – National Technical University "Kharkiv Polytechnic Institute", 2019. The tеhesis is devoted to the solution of the scientific and practical problem of improvement of the water passages of the high-pressure reversible hydraulic due to calculation and analysis their hydrodynamic characteristics. Based on the review of the trends in the development of hydropower engineering in Ukraine and given the role of high-pressure reversible hydraulic machines in the United Power System, it was noted that the designing a new flow parts is topical task. Advantages and disadvantages of the existing methods for research hydrodynamic processes in water passages of reversible hydraulic machines were identified after their analysis. The results of the calculation of the hydrodynamic characteristics of the elements of the water passages based on the method of averaged dimensionless parameters using the example of reversible hydraulic machines OPO200-B-100 and OPO500-B-100 were demonstrated. The mathematical model of the hydraulic machine working process based on a block-hierarchical approach was used to study the energy balance in the turbine and pump modes of hydraulic machines. The influence of the geometrical parameters of the elements of the water passage on the performance was determined: how the angle of flow in the spiral casing (cп ), the height of the wicket gate (b0 D) and the shape of the wicket gate profile influence the value of the coefficient resistance in the wicket gate. A numerical study of the three-dimensional flow of fluid in the water passage of high-pressure reversible hydraulic machines was carried out using the CFD software. This program allows determining the character of the flow and presenting the fields of distribution of velocity components, pressure and streamlines. The balances of energy were compiled: for the OPO200-B-100 in the turbine and pump operation modes, for the OPO500-B-100 in the turbine operation mode. It is noted that the distribution of losses on the elements of the water passage is not uniform: for the OPO200-B-100, the greatest part of the total losses are losses in the runner (about 56%), for OPO500-B-100 - losses in the inlet (about 62%). The main points for determining the optimal operating mode of the reversible hydraulic machine are described. The modified inlet for low-speed high-pressure hydraulic machine OPO500-B-100 was proposed and investigated to increase energy performance of hydraulic machine. The spiral casing was expanded, the number of stay vane blades and wicket gate blades were reduced to 16. As a result of the calculations of the modified inlet, the obtained results showed that the second variant made it possible to better align the elements of the water passage and the hydraulic efficiency increased by 2 %.
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Sattouf, Mousa. "Systém snímání dat a ovládání vodní elektrárny prostřednictvím internetové techniky." Doctoral thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2015. http://www.nusl.cz/ntk/nusl-233685.
Повний текст джерелаАнотація:
Vodní energie se nyní stala nejlepším zdrojem elektrické energie na zemi. Vyrábí se pomocí energie poskytované pohybem nebo pádem vody. Historie dokazuje, že náklady na tuto elektrickou energii zůstávají konstantní v průběhu celého roku. Vzhledem k mnoha výhodám, většina zemí nyní využívá vodní energie jako hlavní zdroj pro výrobu elektrické energie.Nejdůležitější výhodou je, že vodní energie je zelená energie, což znamená, že žádné vzdušné nebo vodní znečišťující látky nejsou vyráběny, také žádné skleníkové plyny jako oxid uhličitý nejsou vyráběny, což činí tento zdroj energie šetrný k životnímu prostředí. A tak brání nebezpečí globálního oteplování. Použití internetové techniky k ovladání několika vodních elektráren má velmi významné výhody, jako snížení provozních nákladů a flexibilitu uspokojení změny poptávky po energii na straně spotřeby. Také velmi efektivně čelí velkým narušením elektrické sítě, jako je například přidání nebo odebrání velké zátěže, a poruch. Na druhou stranu, systém získávání dat poskytuje velmi užitečné informace pro typické i vědecké analýzy, jako jsou ekonomické náklady, predikce poruchy systémů, predikce poptávky, plány údržby, systémů pro podporu rozhodování a mnoho dalších výhod. Tato práce popisuje všeobecný model, který může být použit k simulaci pro sběr dat a kontrolní systémy pro vodní elektrárny v prostředí Matlab / Simulink a TrueTime Simulink knihovnu. Uvažovaná elektrárna sestává z vodní turbíny připojené k synchronnímu generátoru s budicí soustavou, generátor je připojen k veřejné elektrické síti. Simulací vodní turbíny a synchronního generátoru lze provést pomocí různých simulačních nástrojů. V této práci je upřednostňován SIMULINK / MATLAB před jinými nástroji k modelování dynamik vodní turbíny a synchronního stroje. Program s prostředím MATLAB SIMULINK využívá k řešení schematický model vodní elektrárny sestavený ze základních funkčních bloků. Tento přístup je pedagogicky lepší než komplikované kódy jiných softwarových programů. Knihovna programu Simulink obsahuje funkční bloky, které mohou být spojovány, upravovány a modelovány. K vytvoření a simulování internetových a Real Time systémů je možné použít bud‘ knihovnu simulinku Real-Time nebo TRUETIME, v práci byla použita knihovna TRUETIME.
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Vaezi, Masoud. "Modeling and control of hydraulic wind power transfer systems." Thesis, 2014. http://hdl.handle.net/1805/6172.
Повний текст джерелаАнотація:
Indiana University-Purdue University Indianapolis (IUPUI)Hydraulic wind power transfer systems deliver the captured energy by the blades to the generators differently. In the conventional systems this task is carried out by a gearbox or an intermediate medium. New generation of wind power systems transfer the captured energy by means of high-pressure hydraulic fluids. A hydraulic pump is connected to the blades shaft at a high distance from the ground, in nacelle, to pressurize a hydraulic flow down to ground level equipment through hoses. Multiple wind turbines can also pressurize a flow sending to a single hose toward the generator. The pressurized flow carries a large amount of energy which will be transferred to the mechanical energy by a hydraulic motor. Finally, a generator is connected to the hydraulic motor to generate electrical power. This hydraulic system runs under two main disturbances, wind speed fluctuations and load variations. Intermittent nature of the wind applies a fluctuating torque on the hydraulic pump shaft. Also, variations of the consumed electrical power by the grid cause a considerable load disturbance on the system. This thesis studies the hydraulic wind power transfer systems. To get a better understanding, a mathematical model of the system is developed and studied utilizing the governing equations for every single hydraulic component in the system. The mathematical model embodies nonlinearities which are inherited from the hydraulic components such as check valves, proportional valves, pressure relief valves, etc. An experimental prototype of the hydraulic wind power transfer systems is designed and implemented to study the dynamic behavior and operation of the system. The provided nonlinear mathematical model is then validated by experimental result from the prototype. Moreover, this thesis develops a control system for the hydraulic wind power transfer systems. To maintain a fixed frequency electrical voltage by the system, the generator should remain at a constant rotational speed. The fluctuating wind speed from the upstream, and the load variations from the downstream apply considerable disturbances on the system. A controller is designed and implemented to regulate the flow in the proportional valve and as a consequence the generator maintains its constant speed compensating for load and wind turbine disturbances. The control system is applied to the mathematical model as well as the experimental prototype by utilizing MATLAB/Simulink and dSPACE 1104 fast prototyping hardware and the results are compared.
Книги з теми "Hydraulic turbines Models"
1
Tondl, Aleš. Analysis of the transient processes in models of pump-turbines after sudden unloading. Praha: SNTL, 1986.
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2
Evaluation of techniques for detection of cavitation on the runner of a model hydraulic turbine. Denver, Colo: U.S. Bureau of Reclamation, 1991.
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3
McDonnell Douglas Astronautics Company--Houston Division. and United States. National Aeronautics and Space Administration., eds. Independent Orbiter assessment: Weibull analysis report. [Houston, Tex.?: McDonnell Douglas Astronautics Company, 1987.
Знайти повний текст джерелаЧастини книг з теми "Hydraulic turbines Models"
1
Pedrizzetti, G., and G. Angelico. "Model for Vortex Rope Dynamics in Francis Turbine Outlet." In Hydraulic Machinery and Cavitation, 915–24. Dordrecht: Springer Netherlands, 1996. http://dx.doi.org/10.1007/978-94-010-9385-9_93.
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2
Dupont, Ph, J. F. Caron, F. Avellan, P. Bourdon, P. Lavigne, M. Farhat, R. Simoneau, et al. "Cavitation Erosion Prediction on Francis Turbines. Part 2 Model Tests and Flow Analysis." In Hydraulic Machinery and Cavitation, 574–83. Dordrecht: Springer Netherlands, 1996. http://dx.doi.org/10.1007/978-94-010-9385-9_58.
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3
Cattanei, A., A. Capozza, and P. Molinaro. "Analysis of a Numerical Model for the Oscillatory Properties of a Francis Turbine Group." In Hydraulic Machinery and Cavitation, 681–90. Dordrecht: Springer Netherlands, 1996. http://dx.doi.org/10.1007/978-94-010-9385-9_69.
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4
Yuan, Xinjian. "Fractional Order Control for Hydraulic Turbine System Based on Nonlinear Model." In Foundations and Applications of Intelligent Systems, 287–96. Berlin, Heidelberg: Springer Berlin Heidelberg, 2013. http://dx.doi.org/10.1007/978-3-642-37829-4_24.
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5
Kurzin, V. B., S. N. Korobeinikov, V. P. Ryabchenko, and L. A. Tkacheva. "Three-Dimensional Coupled Model for Aeroelastic Analysis of Turbomachine Blade Vibrations. Its Application to a Hydraulic Turbine Rotor." In Unsteady Aerodynamics and Aeroelasticity of Turbomachines, 303–15. Dordrecht: Springer Netherlands, 1998. http://dx.doi.org/10.1007/978-94-011-5040-8_20.
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"Advances in Fisheries Bioengineering." In Advances in Fisheries Bioengineering, edited by Blaine D. Ebberts, Noah S. Adams, Thomas J. Carlson, Derrek M. Faber, Matthew D. Hanson, Robert L. Johnson, Karen A. Kuhn, and Gene R. Ploskey. American Fisheries Society, 2008. http://dx.doi.org/10.47886/9781934874028.ch12.
Повний текст джерелаАнотація:
Abstract.—Surface flow bypass (SFB) concept was evaluated by the Portland District Corps of Engineers to increase survival of emigrant juvenile salmonids passing hydroelectric facilities on the lower Columbia and Snake rivers. Although surface oriented flow had shown promise as efficient juvenile salmonid passage routes, fish behavioral and engineering criteria were lacking to ensure that the most promising prototypes could be evaluated. Surface-oriented sluiceways have long been known to pass a high percentage of juvenile salmonids per the volume of water passed. Also, the Wells Project on the mid-Columbia River had shown great success with deep-slot entrances. A bioengineering evaluation conducted by the Portland District Corps of Engineers and their contractors determined that a stand-alone deep-slot SFB would be the best alternative (alternative A) to evaluate at Bonneville first powerhouse. However, testing the concept of alternative A would be cost prohibitive from a standpoint of handling the flow. So, the prototype surface collector (PSC) was constructed as a “test box” in order to alter the hydraulic environment as drastically as possible to best evaluate the deep slot concept. Hydraulic evaluations consisted of physical hydraulics using a 1:25 powerhouse sectional model, a 1:55 powerhouse forebay model, and prototype hydraulics. Biological evaluations consisted of behavioral data from multibeam and split-beam hydroacoustics, threedimensional acoustic telemetry, and radio telemetry. Efficiency evaluations consisted of radio telemetry and fixed hydroacoustics. The PSC provided positive results for the deep-slot concept, although we cannot report that we broke the salmonid “behavioral code.” Collection efficiency was determined to be 83% for steelhead <em>Oncorhynchus mykiss</em>, 79% for yearling Chinook salmon <em>O. tshawytscha</em>, and 84% for subyearling Chinook salmon. Three years of investigations indicate that the PSC was a well-designed prototype that provided a thorough evaluation of the SFB deep slot concept. The only shortfall from a biological stand point was that the ramp associated with alternative A and associated fish passage was not evaluated. The only shortfall from an engineering stand point was that the lost turbine efficiency due to the turbine intake blockage was not evaluated.
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"Advances in Fisheries Bioengineering." In Advances in Fisheries Bioengineering, edited by Blaine D. Ebberts, Noah S. Adams, Thomas J. Carlson, Derrek M. Faber, Matthew D. Hanson, Robert L. Johnson, Karen A. Kuhn, and Gene R. Ploskey. American Fisheries Society, 2008. http://dx.doi.org/10.47886/9781934874028.ch12.
Повний текст джерелаАнотація:
Abstract.—Surface flow bypass (SFB) concept was evaluated by the Portland District Corps of Engineers to increase survival of emigrant juvenile salmonids passing hydroelectric facilities on the lower Columbia and Snake rivers. Although surface oriented flow had shown promise as efficient juvenile salmonid passage routes, fish behavioral and engineering criteria were lacking to ensure that the most promising prototypes could be evaluated. Surface-oriented sluiceways have long been known to pass a high percentage of juvenile salmonids per the volume of water passed. Also, the Wells Project on the mid-Columbia River had shown great success with deep-slot entrances. A bioengineering evaluation conducted by the Portland District Corps of Engineers and their contractors determined that a stand-alone deep-slot SFB would be the best alternative (alternative A) to evaluate at Bonneville first powerhouse. However, testing the concept of alternative A would be cost prohibitive from a standpoint of handling the flow. So, the prototype surface collector (PSC) was constructed as a “test box” in order to alter the hydraulic environment as drastically as possible to best evaluate the deep slot concept. Hydraulic evaluations consisted of physical hydraulics using a 1:25 powerhouse sectional model, a 1:55 powerhouse forebay model, and prototype hydraulics. Biological evaluations consisted of behavioral data from multibeam and split-beam hydroacoustics, threedimensional acoustic telemetry, and radio telemetry. Efficiency evaluations consisted of radio telemetry and fixed hydroacoustics. The PSC provided positive results for the deep-slot concept, although we cannot report that we broke the salmonid “behavioral code.” Collection efficiency was determined to be 83% for steelhead <em>Oncorhynchus mykiss</em>, 79% for yearling Chinook salmon <em>O. tshawytscha</em>, and 84% for subyearling Chinook salmon. Three years of investigations indicate that the PSC was a well-designed prototype that provided a thorough evaluation of the SFB deep slot concept. The only shortfall from a biological stand point was that the ramp associated with alternative A and associated fish passage was not evaluated. The only shortfall from an engineering stand point was that the lost turbine efficiency due to the turbine intake blockage was not evaluated.
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Yang, Hongfeng, Rui Ji, Huali Hu, Weitong He, Bingsen Chen, and Qibo Liu. "Nara Hydropower Station’s Installed Capacity and Model Selection for Efficiency Enhancement and Capacity Expansion." In Advances in Transdisciplinary Engineering. IOS Press, 2022. http://dx.doi.org/10.3233/atde220964.
Повний текст джерелаАнотація:
Since the Nara Hydropower Station was put into operation, it has far exceeded the designed service life of 25 years. The generator insulation is seriously aging, the water leakage of the turbine is large, the working efficiency of the unit is low, the operation failure occurs frequently, and the hidden safety problems are prominent. At present, the upstream cascade power station and the leading reservoir have been constructed and put into operation, and the hydraulic resources of the basin have been adjusted annually. By collecting hydrological data, re-calculating and determining the average annual water flow that can be used for power generation of the power station, and determining the overall plan for maintaining the existing power station dam and reforming other hydraulic structures, and then comparing and demonstrating the technical and economic plans, it is clear that the power station The total installed capacity and the number of units were optimized, new and high-efficiency hydro-generator units were selected, and the operation plan was formulated scientifically and rationally. After the renovation, the average annual power generation of the power station was 492% of that before the renovation.
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Singh, Balvender, and Shree Krishan Bishnoi. "An Application of ANFIS-PID Controller for Multi Area Hybrid Power System." In Artificial Intelligence and Communication Technologies, 613–27. 2022nd ed. Soft Computing Research Society, 2022. http://dx.doi.org/10.52458/978-81-955020-5-9-59.
Повний текст джерелаАнотація:
In this work adaptive fuzzy- PID (ANFIS-PID) controller is presented for frequency and tie-line regulation of multi-area interconnected power systems (IPS). The proposed controller has the properties of both neural network and fuzzy logic. A novel four area power system comprises two reheat turbines (area1 and area2), one hydropower plant (area 3) with the hydraulic governor and one wind plant (area 4) with a pitch actuator. This hybrid interconnected power system model has been built in MATLAB/ Simulink version 2020(a) and the proposed controller is employed with the same design of ANFIS model in all areas. Further, the performance of power system model is presented with the suggested controller. The step load change is considered in each area. An HVDC lines are considered in each area to improve the performance of the proposed model. Further, a fair comparison is made for the conventional PID and Fuzzy-PID controllers. The designed controller performs best compared to the other compared controller for tie-line power and frequency regulation in all four areas of the IPS. The dynamic response of the proposed model improves with AC/DC line as compared to AC line. The sensitivity analysis with change in plant parameters, step load perturbation (SLP) and random load change is also being applied to check the robustness of the controller.
Тези доповідей конференцій з теми "Hydraulic turbines Models"
1
Ayli, Ece, Berat Kavurmaci, Kutay Celebioglu, and Selin Aradag. "Design and Construction of an Experimental Test Rig for Hydraulic Turbines." In ASME 2014 12th Biennial Conference on Engineering Systems Design and Analysis. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/esda2014-20040.
Повний текст джерелаАнотація:
Every turbine for every hydroelectric power plant is unique; therefore its model has to be designed using state of the art design techniques and tested before the actual prototype which is costly, is manufactured. In this study, the details of the design and construction of a hydroturbine test facility at TOBB University of Economics and Technology are explained. The facility will be used to test hydroturbine models up 2MWs of power simulating turbine prototypes. The performance and cavitation tests of the turbines will be performed utilizing this facility according to International Electrical Commission (IEC) standards. The test facility is 19 meters long with a base area of around 600 meter squares. The hydraulic analysis of the designed set-up is performed using a system where valves, pipes, structures, water records and connections form an intelligent system, same with the experimental facility. According to the results, system performance is checked, alternative designs are evaluated and operating strategies are defined by minimizing the losses.
2
Cho, Hyunkyoo, Ujjwal Shrestha, Young-Do Choi, and Jungwan Park. "Global Sensitivity Analysis for Stay Vane and Casing Design of Reaction Hydraulic Turbine." In ASME-JSME-KSME 2019 8th Joint Fluids Engineering Conference. American Society of Mechanical Engineers, 2019. http://dx.doi.org/10.1115/ajkfluids2019-4684.
Повний текст джерелаАнотація:
Abstract Global sensitivity analysis (GSA) estimates influence of design variables in the entire design domain on performance measures. Hence, using GSA, important design variables could be found for an engineering application with high dimension which require computationally expensive analyses. Then, similar engineering applications could use selected variables to carry out design process with smaller dimension and affordable computational cost. In this study, GSA has been carried out for the performance measures in design of stay vane and casing of reaction hydraulic turbines. Global sensitivity index method is used for GSA because it can fully capture the effect of interaction between the design variables. For efficiency, genetic aggregation surrogate models are constructed using the responses of computational fluid dynamic (CFD) analysis. Global sensitivity indices for the performance measures of stay vane and casing have been evaluated using the surrogate models. It is found that less than three design variables among 12 are effective in the design process of stay vane and casing in reaction hydraulic turbines.
3
Childs, Dara W., and Ameen Muhammed. "Comments on a Newly-Identified Destabilizing Rotordynamic Mechanism Arising in Vertical Hydraulic Turbines and the Back Shrouds of Centrifugal Impellers." In ASME Turbo Expo 2013: Turbine Technical Conference and Exposition. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/gt2013-94202.
Повний текст джерелаАнотація:
In three 2010 papers, Tsujimoto, Ma, Song, and Horiguchi [1–3] discussed and explained a novel destabilizing mechanism arising in both hydraulic turbines and the back surface of vertical pump impellers. The destabilizing mechanism can be explained via a reaction force-moment model that includes both the customary radial displacement vector of an impeller plus the pitch and yaw degrees of freedom. This coupling between radial displacements and tilt plus the coupling of the shaft support structure can create negative damping. In 1993, Verhoeven, et al. [4] identified negative damping arising from U-shaped wearing-ring seals as causing a super-synchronous instability in a horizontal coke-crusher pump. However, several case studies have been presented of super-synchronously unstable pumps for which (until now) no explanation could be provided. Tsujimoto-Song started with a 2DOF model for a disk suspended vertically via a cantilevered shaft. They used an f = ma model for the lateral displacements of the disk and used flexibility coefficients to account for reaction forces and moments from the back shroud of the impeller. The present work starts with a 4DOF model that includes the disk’s displacements and pitch and yaw degrees of freedom. Guyan reduction is used to create two reduced 2DOF models, Model A that retains the displacements and discards the rotations and Model B that retains the rotations and discards the displacements. Model A produces a requirement for instability that is inconsistent with Tsujimoto-Song’s experience and predictions. However, it is useful in predicting the reaction moments produced by a nominally planar precession of the impeller. The instability requirement of Model B is consistent with Tsujimoto’s experience and predictions. A comparison of the predicted reaction moments of Model A and Tsujimoto’s reaction-moment data supports the instability predictions of Model B (and Tsujimoto-Song) that the instability arises due to coupling between the displacement and rotation degrees of freedom in the 4 × 4 damping matrix.
4
Brizuela, Edward A. "A Contribution to the Study of Exit Flow Angle in Radial Turbines." In ASME 1991 International Gas Turbine and Aeroengine Congress and Exposition. American Society of Mechanical Engineers, 1991. http://dx.doi.org/10.1115/91-gt-010.
Повний текст джерелаАнотація:
The emergence and evolution of relative whirling motions in the exducer region of an Inward Flow Radial Turbine is discussed. Existing models of relative motion are reviewed and expanded by consideration of the effect of centrifugal forces differences arising from velocity gradients. It is shown that the often observed phenomenon of outlet overturn/underturn is inherent to the use of straight-helix exducers. Explicit mathematical relationships between exit velocities and radius are not available. If, however, such relationships could be considered linear, it is shown that two new reference radii may be identified such that the net outlet properties can be measured or computed at these locations as lump parameters. These radii are different from the often used hydraulic radius. The new models and reference radii are verified using published experimental data.
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Escobedo, Ernesto, Liliana Arguello, Marzia Sepe, Ilaria Parrella, Stefano Cioncolini, and Carmine Allegorico. "Enhanced Early Warning Diagnostic Rules for Gas Turbines Leveraging on Bayesian Networks." In ASME Turbo Expo 2020: Turbomachinery Technical Conference and Exposition. American Society of Mechanical Engineers, 2020. http://dx.doi.org/10.1115/gt2020-16082.
Повний текст джерелаАнотація:
Abstract The monitoring and diagnostics of Industrial systems is increasing in complexity with larger volume of data collected and with many methods and analytics able to correlate data and events. The setup and training of these methods and analytics are one of the impacting factors in the selection of the most appropriate solution to provide an efficient and effective service, that requires the selection of the most suitable data set for training of models with consequent need of time and knowledge. The study and the related experiences proposed in this paper describe a methodology for tracking features, detecting outliers and derive, in a probabilistic way, diagnostic thresholds to be applied by means of hierarchical models that simplify or remove the selection of the proper training dataset by a subject matter expert at any deployment. This method applies to Industrial systems employing a large number of similar machines connected to a remote data center, with the purpose to alert one or more operators when a feature exceeds the healthy distribution. Some relevant use cases are presented for an aeroderivative gas turbine covering also its auxiliary equipment, with deep dive on the hydraulic starting system. The results, in terms of early anomaly detection and reduced model training effort, are compared with traditional monitoring approaches like fixed threshold. Moreover, this study explains the advantages of this probabilistic approach in a business application like the fleet monitoring and diagnostic advanced services.
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Lemmer (né Sandner), Frank, Wei Yu, Po Wen Cheng, Antonio Pegalajar-Jurado, Michael Borg, Robert F. Mikkelsen, and Henrik Bredmose. "The TripleSpar Campaign: Validation of a Reduced-Order Simulation Model for Floating Wind Turbines." In ASME 2018 37th International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2018. http://dx.doi.org/10.1115/omae2018-78119.
Повний текст джерелаАнотація:
Different research groups have recently tested scaled floating offshore wind turbines including blade pitch control. A test conducted by the University of Stuttgart (Germany), DTU (Denmark) and CENER (Spain) at the Danish Hydraulic Institute (DHI) in 2016 successfully demonstrated a real-time blade pitch controller on the public 10MW TripleSpar semi-submersible concept at a scale of 1/60. In the presented work a reduced-order simulation model including control is compared against the model tests. The model has only five degrees of freedom and is formulated either in the time-domain or in the frequency-domain. In a first step the Morison drag coefficients are identified from decay tests as well as irregular wave cases. The identified drag coefficients depend clearly on the sea state, with the highest ones for the decay tests and small sea states. This is an important finding, for example for the design of a robust controller, which depends on the system damping. It is shown that the simplified model can well represent the dominant physical effects of the coupled system with a substantially reduced simulation time, compared to state-of-the-art models.
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Wang, C., and Y. G. Li. "Hydraulic Fuel System Simulation Using Newton-Raphson Method and its Integration With a Gas Turbine Performance Model." In ASME Turbo Expo 2017: Turbomachinery Technical Conference and Exposition. American Society of Mechanical Engineers, 2017. http://dx.doi.org/10.1115/gt2017-63881.
Повний текст джерелаАнотація:
A fuel system in a gas turbine engine is to meter and deliver required fuel flow to the engine in order to power its operation. A hydraulic fuel system may consist of pumps, valves and metering unit. The fuel has to be sucked from a reservoir, pressurized by the pumps, and regulated by the valves before being injected into an engine combustion chamber. A slight delay of fuel system component response may result in noticeable impact on the engine transient performance response. In this paper, a novel method for engine hydraulic fuel system performance prediction based on Newton-Raphson approach has been introduced. A gas turbine transient performance simulation system has been set up, where gas turbines are simulated with an inter-component volume method, control systems are simulated with a proportional-integral (PI) controller and hydraulic fuel systems are simulated with a new fuel system model based on Newton-Raphson method introduced in this paper. The developed performance simulation system has been applied to a model one-spool aero gas turbine engine similar to Rolls-Royce AVON. A typical transient process of the model engine has been simulated to investigate the effectiveness of the introduced fuel system simulation method and the coupling effect between the gas turbine and the fuel system. Results show that the inclusion of a fuel system model will result in a noticeable delay in engine transient behaviour compared with that without the inclusion of the fuel system model although such delay is relatively small. Such modelling method can help set up physics-based fuel system models and analyse the detailed behaviour and mechanism of the fuel systems during engine transient processes. This may provide very useful information to assist the understanding of engine performance behaviour and support the designs of engines, control systems or fuel systems. Such method is generic and can be applied to different hydraulic fuel systems.
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Bozorgi, A., A. Riasi, and A. Nourbakhshi. "Investigation of Several Turbulence Models in Simulation of an Axial PAT for a Small Hydropower Using as Renewable Source of Energy." In ASME 2011 International Mechanical Engineering Congress and Exposition. ASMEDC, 2011. http://dx.doi.org/10.1115/imece2011-64909.
Повний текст джерелаАнотація:
Small hydropower stations as one of the clean and renewable resources of energy have great capacity to generate electricity and with increasing energy demands, using such potentials is quite necessary. One of the suitable choices for utilizing small hydropower resources is using pump as turbine (PAT), which means using pump in reverse mode. Pumps are relatively simple and inexpensive machines, easy to maintain and readily available in many of developing countries. Several methods have been developed to predict operation of pumps running as turbines but their results are not in good coincidence with experimental data for all pumps. Therefore, study and investigation of hydraulic behavior of pumps in reverse mode can be useful. In this work, an axial pump is simulated in reverse mode by computational fluid dynamics. Reynolds-Averaged Navier–Stokes equations are solved using different turbulence models in NUMECA software environment. Characteristic curves of the reverse pump are obtained for each turbulence model and results are compared with experimental data. The results show that Spallart-Allmaras can predict operation of the axial PAT better than other models.
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Franco-Nava, Jose Manuel, Erik Rosado-Tamariz, Oscar Dorantes-Gomez, Jose´ Manuel Ferna´ndez-Da´vila, and Reynaldo Rangel-Espinosa. "CFD Performance Evaluation and Runner Blades Design Optimization in a Francis Turbine." In ASME 2009 Fluids Engineering Division Summer Meeting. ASMEDC, 2009. http://dx.doi.org/10.1115/fedsm2009-78413.
Повний текст джерелаАнотація:
The application of computational fluid dynamics (CFD) in the redesign or rehabilitation of hydraulic turbines appears to be necessary in order to improve their efficiency and cost-effectiveness beyond the traditional redesign practices. The runner geometry considered within the computational domain was modelled by using a three-dimensional laser triangulation scanner coupled with a portable coordinate measurement system. The runner geometry was generated by a number of 3D sub models, one for each of the main components of the runner, crown, band and a blade. In order to obtain a blade geometry a portable coordinate measurement system based on optical digitalization technology (scanner technology) was used. A numerical optimization methodology is developed and applied to a Francis turbine. The hydrodynamic performance analysis was investigated by application of a three dimensional Navier-Stoke commercial turbomachinery oriented CFD code. Analysis of the flow through the spiral case and stay vanes was carried out so as to include appropriate flow effects induced by these components and boundary conditions at the inlet of the wicket. A CFD analysis for the wicket and runner was carried out to generate the so called reference solution. Then, the runner blades design was optimized by a process implemented in a commercial CFD code which combines genetic algorithms and a trained artificial neural network (ANN). A database of geometries and their respective CFD computations were computed in order to determine the optimum geometry for a given objective function. The flow within hydraulic turbines has a thin boundary layer and noticeable pressure gradients. Hence, the CFD computations were carried out using the Sparlat-Allmaras turbulence model. After optimization cycle convergence, an increment not only in efficiency but also in power was obtained. The optimized runner represented by a parametric model achieves considerably higher efficiency than the reference runner. Efficiency versus power curve was used to compare data from measurements at the power station for the reference runner versus the parametric optimized runner model. Results have shown that application of CFD based optimization can modify and improve runners design so as to increase the efficiency and power of installed hydraulic power stations.
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Walsh, Rowan W., Hossein Hosseinimanesh, Seyed Nourbakhsh, Mohammad Meshkahaldini, and Amy M. Bilton. "Modeling and Experimental Validation of a Pico-Scale Francis Turbine for a Self-Powered Water Disinfection System." In ASME 2018 Power Conference collocated with the ASME 2018 12th International Conference on Energy Sustainability and the ASME 2018 Nuclear Forum. American Society of Mechanical Engineers, 2018. http://dx.doi.org/10.1115/power2018-7312.
Повний текст джерелаАнотація:
Access to both electricity and clean drinking water is challenging in many remote communities. A self-powered water disinfection system, currently under development, can potentially address this challenge. In the proposed design, energy from water flowing through the system is harnessed using a pico turbine (nominal output power of 60 W) and used to power an electrochemical disinfection process. The characteristics of turbines at the pico-scale (less than 5kW) required for this system are not well researched, and off-the-shelf designs are either too bulky or too inefficient for this application. This paper presents a model developed to evaluate a new class of efficient pico-scale Francis turbines for this water disinfection system. A computational fluid dynamics (CFD) model of the turbine was developed in ANSYS® CFX® 17.1. The CFD model exploits the rotational symmetry of the turbine and draft tube fluid regions to reduce the computational cost in terms of time and memory. The turbine model is coupled with models of the electric generator and electrochemical cell to determine the balanced operating points. When validated against experimental data, the combined model showed good predictive ability despite its low computational cost: the modeled turbine efficiency is within 5% of the measured values across the operating range of the device. The current turbine design has a hydraulic efficiency above 60 % in its operating range, which is high for a compact turbine at this scale. The combined model was used with a parameterized version of the turbine geometry to identify key performance sensitivities, particularly with the blade trailing edge angle. Turbine efficiency was improved by more than 2 % across the allowable flow rates. The low computational cost of the combined model made it well suited for iterative design optimization, supplanting the need for lengthy experimental trials. Overall, the modeling approach presented here shows good promise for use in picoturbine design.