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Hydropower, wind power, and photovoltaic power generation are the most common clean energy sources and are important ways to achieve “carbon neutrality” and “carbon peak”. With the adjustment of China’s energy structure, wind power and photovoltaic power generation have entered the peak period of development, but the above two forms of power generation have a certain degree of instability, which has increased the risk of safe and stable operation of the power grid. In contrast, hydroelectric power generation has good stability, and giving full play to the excellent peak and frequency modulation functions of hydro-generator sets is of great significance to ensuring the safe and stable operation of the power grid. This requires the hydro-generator unit to have good reliability during the service period. Through the evaluation of the unit’s health status, the unit’s health status can be predicted, and the maintenance strategy can be given to eliminate the fault in the budding state. This article summarizes the health status assessment methods of hydro-turbine generator sets, and puts forward five health status levels: “healthy”, “good”, “attention”, “abnormal” and “dangerous”. This paper has carried out a quantitative calculation on the health status of a certain hydraulic turbine. The results show that the degree of health of the turbine is “healthy”, “good”, “attention”, “abnormal” and “dangerous” respectively and the degrees are 0.065, 0.632, 0.279, 0.024, 0. According to the principle of maximum membership, it can be judged that the turbine is in “good” status. The evaluation result is consistent with the actual operation of the unit, indicating that the evaluation method studied in this paper has a certain practicability and can provide scientific guidance for the health evaluation of the hydroelectric generating unit.

Global renewable energy requirements rapidly increase with the transition to a fossil-free society. As a result, intermittent energy resources, such as wind- and solar power, have become increasingly popular. However, their energy production varies over time, both in the short- and long term. Hydropower plants are therefore utilized as a regulating resource more frequently to maintain a balance between production and consumption on the electrical grid. This means that they must be operated away from the design point, also known as the best-efficiency-point (BEP), and often are operated at part-load (PL) with a lower power output. Moreover, some plants are expected to provide a spinning reserve, also referred to as speed-no-load (SNL), to respond rapidly to power shortages. During this operating condition, the turbine rotates without producing any power. During the above mentioned off-design operating conditions, the flow rate is restricted by the closure of the guide vanes. This changes the absolute velocity of the flow and increases the swirl, which is unfavorable. The flow field can be described as chaotic, with separated regions and recirculating fluid. Shear layer formation between stagnant- and rotating flow regions can be an origin for rotating flow structures. Examples are the rotating-vortex-rope (RVR) found during PL operation and the vortical flow structures in the vaneless space during SNL operation, which can cause the flow between the runner blades to stall, also referred to as rotating stall. The flow structures are associated with pressure pulsations throughout the turbine, which puts high stress on the runner and other critical parts and shortens the turbine's lifetime. Numerical models of hydraulic turbines are highly coveted to investigate the detrimental flow inside the hydraulic turbines' different sections at off-design operating conditions. They enable the detailed study of the flow and the origin of the instabilities. This knowledge eases the design and assessment of mitigation techniques that expand the turbines' operating range, ultimately enabling a wider implementation of intermittent energy resources on the electrical grid and a smoother transition to a fossil-free society. This thesis presents the numerical study of the Porjus U9 model, a scaled-down version of the 10 MW prototype Kaplan turbine located along the Luleå river in northern Sweden. The distributor contains 20 guide vanes, 18 stay vanes and the runner is 6-bladed. The numerical model is a geometrical representation of the model turbine located at Vattenfall Research and Development in Älvkarleby, Sweden. The commercial software ANSYS CFX 2020 R2 is used to perform the numerical simulations. Firstly, the draft tube cone section of the U9 model is numerically studied to investigate the sensitivity of a swirling flow to the GEKO (generalized kω) turbulence model. The GEKO model aims to consolidate different eddy viscosity turbulence models. Six free coefficients are changeable to tune the model to flow conditions and obtain results closer to an experimental reference without affecting the calibration of the turbulence model to basic flow test cases. Especially, the coefficients affecting wall-bounded flows are of interest. This study aims to analyze if the GEKO model can be used to obtain results closer to experimental measurements and better predict the swirling flow at PL operation compared to other eddy viscosity turbulence models. Results show that the near-wall- and separation coefficients predict a higher swirl and give results closer to experimentally obtained ones. Secondly, a simplified version of the U9 model is investigated at BEP and PL operating conditions and includes one distributor passage with periodic boundary conditions, the runner and the draft tube. The flow is assumed axisymmetric upstream of the runner, hence the single distributor passage. Previous studies of hydraulic turbines operating at PL show difficulties predicting the flow's tangential velocity component as it is often under predicted. Therefore, a parametric analysis is performed to investigate which parameters affect the prediction of the tangential velocity in the runner domain. Results show that the model predicts the flow relatively well at BEP but has problems at PL; the axial velocity is overpredicted while the tangential is underpredicted. Moreover, the torque is overpredicted. The root cause for the deviation is an underestimation of the head losses. Another contributing reason is that the runner extracts too much swirl from the flow, hence the low tangential velocity and the high torque. Sensitive parameters are the blade clearance, blade angle and mass flow. Finally, the full version of the U9 model is analyzed at SNL operation, including the spiral casing, full distributor, runner and draft tube. During this operating condition, the flow is not axisymmetric; vortical flow structures extend from the vaneless space to the draft tube and the flow stalls between the runner blades. A mitigation technique with independent control of each guide vane is presented and implemented in the model. The idea is to open some of the guidevanes to BEP angle while keeping the remaining ones closed. The aim is to reduce the swirl and prevent the vortical flow structures from developing. Results show that the flow structures are broken down upstream the runner and the rotating stall between the runner blades is reduced, which decreases the pressure- and velocity fluctuations. The flow down stream the runner remains mainly unchanged.

На конкретном примере показаны особенности протекания переходных процессов на ГЭС с турбинами двойного регулирования. Приводятся рекомендации по выбору режимов движения регулирующих органов для снижения отрицательных осевых усилий, действующих на рабочее колесо турбины, что может приводить к подбросу агрегата и другим опасным явлениям в агрегатных блоках ГЭС., A concrete example shows the features of the transient processes at a hydroelectric power station with dual-control turbines. Recommendations are given on the choice of modes of movement of regulatory bodies to reduce the negative axial forces acting on the turbine impeller, which can lead to the tossing of the unit and other dangerous phenomena in the aggregate blocks of hydroelectric power plants., Гидротехническое строительство, Выпуск 2 2023, Pages 15-18

В ході цього дослідження розробляється та оптимізується програмне забезпечення для аналізу напружено-деформованого стану лопаті низьконапірної поворотно-лопатевої гідротурбіни. Аналізується математична модель, згідно з якою лопать, яка насправді є пологою оболонкою і закріплена частково, замінюється пластиною змінної жорсткості, що представляє в плані кільцевий сектор з затисненим внутрішнім дуговим краєм. В ході дослідження розроблено прикладне програмне забезпечення, яке дозволяє за допомогою варіаційного методу Рітца проводити дослідження напружено-деформованого стану різних лопатей в залежності від їх геометричних і механічних параметрів, а також зовнішніх навантажень. Геометричними параметрами лопаті є: внутрішній і зовнішній радіуси кільцевого сектора, кут кільцевого сектора, максимальна товщина лопаті і інтерполяційна сітка для знаходження відносних товщин лопаті. Механічними параметрами є модуль Юнга і коефіцієнт Пуассона матеріалу, з якого виготовлена лопать, навантаження приймається рівномірно розподіленим. Оскільки товщина лопаті змінна, вхідними даними є відносні товщини лопаті в різних точках. Для обчислення проміжних значень застосовуються білінійна інтерполяція і інтерполяція Лагранжа 9-ї степені. Аналізується точність і обчислювальна складність методів чисельного інтегрування, а саме інтерполяція підінтегральної функції поліномом з подальшим аналітичним обчисленням і використання квадратурної формули, отриманої в результаті повторного інтегрування із застосуванням формули Сімпсона. На підставі порівняння результатів робиться висновок про доцільність застосування поліноміальної інтерполяції з подальшим аналітичним розв’язком. За допомогою розробленого програмного комплексу проводиться розрахунок напружено-деформованого стану пластини, яка апроксимує реальну модель лопаті ЛМЗ (ПЛ510), результати якого порівнюються з експериментальними даними. Здійснюється аналіз декількох конфігурацій лопаті., In this paper, software, that allows studying the stress-strain state of the blade of a low-pressure hydraulic turbine, is being developed. A mathematical model according to which the blade, which is actually a hollow shell and is partially fixed, is replaced by a variable stiffness plate, representing in plan an annular sector with a pinched inner arc edge, is analyzed. In this paper, application software which enables the stress-strain analysis of various blades to be investigated using the Ritz variation method, depending on their geometrical and mechanical parameters as well as external loads, is being developed. The geometrical parameters of the blade are: inner and outer radii of the annular sector, annular sector angle, maximum blade thickness and relative thicknesses at different points. Mechanical parameters are the Young’s modulus and the Poisson's ratio of the material from which the blade is made, and the load is assumed to be evenly distributed. Since the thickness of the blade is variable, the input data is the relative thicknesses of the blade at different points. Bilinear interpolation and Lagrange polynomials of 9th degree are used to calculate the intermediate values. Based on the comparison of the results, the conclusion, that using bilinear interpolation is more expedient for calculating the value of sub-integral function, is made. The accuracy and temporal complexity of the numerical integration methods are analyzed, namely interpolation of the sub-integral function by a polynomial followed by analytical calculation and the use of a quadrature formula resulting from repeated integration using the Simpson’s rule. Based on the comparison of the results, the conclusion, that polynomial interpolation with the subsequent analytical solution is expedient, is made. The developed software package is used to calculate the stress-strain state of the plate that approximates the real LMZ blade (PL510). The results are compared with experimental data. Several blade configurations are also analyzed.

In this work, we theoretically analyzed the main factors affecting performance of multistage energy recovery hydraulic turbine (MERHT), and found that the arc radius (r) of the edge at the outlet section of the runner guide vane is the determining factor of the hydraulic efficiency of hydraulic turbines. To further improve the performance of the MERHT, a numerical model is then proposed to optimize the arc radius. The MERHT-type DCSGT250-175 × 9 was taken in the simulation. The hydraulic efficiency ηh and the corresponding distributions of pressure and velocity were numerically studied with four different values of r ranging from 133.5 to 138 mm. It is found that the flow state and the flow field distribution were the best when r equals to 134 mm. With the optimum r, the external diameter of the runner guide vane (D) was further adjusted, which can lead to 3.9% increase of average efficiency according to the simulation results.

Силова взаємодія вихрових джгутів у відсмоктуючій трубі РО гідротурбін з елементами проточного тракту може приводити до серйозних аварій. Зменшення низькочастотних пульсацій тиску є актуальною задачею, так як сприяє підвищенню надійності і збільшенню потужності гідроагрегатів. Для цього інколи використовують спеціальні пристрої. Метою цієї роботи було порівняння сучасних методик розрахунку низькочастотних джгутових пульсацій тиску у відсмоктуючій трубі з експериментом. Проведені експериментальні дослідження пульсацій тиску у проточній частині і на лопаті робочого колеса гідротурбіни РО115 у широкому діапазоні режимів роботи. Виконані чисельні експерименти по визначенню джгутових пульсацій тиску з використанням просторової математичної моделі по методиці НТУ "ХПІ". З іншого боку, були виконані розрахунки пульсацій тиску на основі сучасного пакета програм гідродинаміки, які вирішують завдання механіки суцільного середовища і використовують рівняння Рейнольдса. Процес вирішення завдань в цьому випадку здійснюється за допомогою пакету прикладних програм CFD, що включає етапи: створення тривимірної моделі розглянутого об'єкта за допомогою системи САПР; побудова розрахункової сітки; вибір математичної моделі турбулентності; завдання граничних умов. Порівняння експериментальних та розрахункових результатів вказують на їх гарне узгодження. Прогнозування пульсацій тиску за приведеними методиками при проектуванні гідротурбін дає можливість в подальшому для вибору кращої проточної частини з меншими пульсаціями тиску (з меншими втратами) і з більш високими енергокавітаційними показниками. У першому випадку для виконання задачі потрібні незначні ресурси машинного часу, а похибка при розрахунку амплітуд пульсацій тиску становить до 15–20 % в порівнянні з експериментальними даними, у другому – 10 % при значно більшому часі розрахунків. Надалі результати розрахунків джгутових пульсацій тиску використовуються в розрахунках на міцність елементів проточної частини гідротурбіни з великими запасами по коефіцієнтам міцності, тому можливе використання математичних моделей різної складності у прогнозних розрахунках джгутових пульсацій тиску у відсмоктуючій трубі. The force interaction of the vortex swirls in the draft tube of the hydraulic turbine RO with the elements of the flow path can lead to serious accidents. Reducing low-frequency pressure pulsations is an urgent task, as it helps to increase the reliability and increase the power of hydraulic units. For this, special devices are sometimes used. The aim this of the work was to compare modern methods for calculating low-frequency bundle pressure pulsations in a draft tube with experiment. Experimental studies of pressure pulsations in the flow part and the impeller blade of the RO115 hydraulic turbine were carried out in a wide range of operating modes. Numerous experiments were carried out to determine the bundle pressure fluctuations using a spatial mathematical model according to the method of NTU ''KhPI''. In addition, calculations of pressure fluctuations were performed based on a modern hydrodynamic software package that solves problems of continuum mechanics and uses the Reynolds equation. The process of solving problems in this case is carried out by means of the CFD application package, which includes the following steps: creating a three-dimensional model of the object under consideration using the CAD system; construction of the computational grid; choice of mathematical model of turbulence; problems of limiting conditions. A comparison of the experimental and calculated results indicates their good agreement. Prediction of pressure fluctuations using the above methods when designing hydraulic turbines makes it possible in the future to choose the best flow path with lower pressure fluctuations (with lower losses) and with higher energy-cavitation performance. In the first case, the task requires insignificant resources of computer time, and the error in calculating the amplitudes of pressure fluctuations is up to 15 % compared with the experimental data, in the second case it is 10 % with a much longer calculation time. In the future, the results of calculations of bundled pressure pulsations are used in strength calculations of elements of the flow path of a hydraulic turbine with large margins in terms of strength factors, so it is possible to use mathematical models of varying complexity in predictive calculations of bundled pressure fluctuations in a draft tube.

An integrated wave-tidal current power turbine is affected by both wave and tidal current forces, and its energy efficiency is closely related to the velocity and direction of the two forces. To improve the probability of the horizontal axis turbine reaching maximum energy efficiency under real-time changing sea conditions, we performed the following investigations in this study. Based on the actual application scenario of Lianyungang port, a time series prediction model of tidal current (velocity and flow direction) and wave (mean wave direction, mean wave period, and significant wave height) data for the past year was established. The changes in waves and tidal currents within 24 h after the cutoff point of the existing data were predicted. The integrated wave-tidal current mechanism was studied, and the superposition of wave energy and tidal current energy was transformed into the equivalent velocity vector of wave-tidal current integration. The conversion coefficient between waves and equivalent flows was determined by a numerical wave flume simulation. According to the historical wave and tidal current data, the equivalent velocity range of the integrated action of waves and tidal currents in Lianyungang was determined. The influence of different blade motions on the energy harvesting efficiency of the turbine under the corresponding flow conditions was studied using the Computational Fluid Dynamics (CFD) method to determine the blade motion law of the turbine. The blade motion law of the prototype was verified in a sea trial experiment. The experimental results were basically consistent with the simulation results for the blade motion law designed according to the wave and tidal current prediction law. This design scheme can provide a reference for engineering design for the development and utilization of new marine energy.

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.

The article shows that an increase in the pressure of the water flow in the hydraulic system after a hydraulic shock (water hammer) can be used to rotate the hydroturbine of a power plant in the same way as when the water pressure is increased in dam hydroelectric plants. The possibilities of using accumulators to stabilize the pressure and flow rate of water after a water hammer are shown. The basic laws of the course of complete and incomplete hydroblow are considered. The advantages of hydraulic shock power plants in comparison with dam hydroelectric power stations and with all other power plants of the same capacity are disclosed. Indisputable advantages include, first of all, the absence of the need for energy consumption from external sources, low costs for design, manufacture and operation. The inertia forces of a constant volume of circulating water are used as a source of renewable energy. The small dimensions of hydroshock power plants make it possible to use them directly in the place of electricity consumption, therefore losses during its transportation are excluded. Water hammer power plants do not affect environmental changes, do not pollute water, air and soil. By regulating the operation of the valves, it is possible to significantly increase the power output of the power plant using modern high-speed solenoid valves or electric valves, which are turned on and off according to a given program. The possibility of using the developed hydraulic shock installation to rotate a bucket hydraulic turbine and generate electricity is being investigated. The widespread introduction of high-impact hydroelectric power plants will permanently get rid of the use of expensive energy sources and keep the human environment clean., В статье показано, что увеличение давления потока воды в гидросистеме после гидравлического удара (гидроудара) можно использовать для вращения гидротурбины электростанции так же, как и при повышении для этого напора воды в плотинных гидроэлектростанциях. Показаны возможности применения гидроаккумуляторов для стабилизации давления и расхода воды после гидроудара. Рассматриваются основные закономерности протекания полного и не полного гидроудара. Раскрыты преимущества гидроударных электростанций по сравнению с плотинными гидроэлектростанциями и со всеми иными электростанциями такой же мощности. К неоспоримым преимуществам относятся прежде всего отсутствие необходимости потребления энергии от внешних источников, низкие затраты на проектирование, изготовление и эксплуатацию. В качестве источника возобновляемой энергии используются силы инерции постоянного объёма циркулирующей воды. Малые габариты гидроударных электростанций позволяют использовать их непосредственно в месте потребления электроэнергии, поэтому исключаются потери при её транспортировке. Гидроударные электростанции не влияют на изменения окружающей среды, не загрязняют воду, воздух и почву. За счет регулирования работы клапанов можно существенно повысить выходную мощность электростанции, используя быстродействующие современные электромагнитные клапаны или клапаны с электроприводом, включение и отключение которых осуществляется по заданной программе. Исследуется возможность использования разработанной гидроударной установки для вращения ковшовой гидротурбины и производства электроэнергии. Широкое внедрение гидроударных электростанций повышенной мощности позволит навсегда избавиться от использования дорогостоящих энергоносителей и сохранить в чистоте среду обитания человека., У статті показано, що збільшення тиску потоку води в гідросистемі після гідравлічного удару (гідроудару) можна використовувати для обертання гідротурбіни електростанції так само, як і при підвищенні для цього напору води в гребельних гідроелектростанціях. Показано можливості застосування гідроакумуляторів для стабілізації тиску і витрати води після гідроудару. Розглядаються основні закономірності перебігу повного і неповного гідроудару. Розкрито переваги гідроударних електростанцій в порівнянні з греблею гідроелектростанції і з усіма іншими електростанціями такої ж потужності. До незаперечних переваг відносяться перш за все відсутність необхідності споживання енергії від зовнішніх джерел, низькі витрати на проектування, виготовлення та експлуатацію. Як джерело відновлюваної енергії використовуються сили інерції постійного об'єму циркулюючої води. Малі габарити гідроударних електростанцій дозволяють використовувати їх безпосередньо в місці споживання електроенергії, тому виключаються втрати при її транспортуванні. Гідроударні електростанції не впливають на зміни навколишнього середовища, не забруднюють воду, повітря і грунт. За рахунок регулювання роботи клапанів можна істотно підвищити вихідну потужність електростанції, використовуючи швидкодіючі сучасні електромагнітні клапани або клапани з електроприводом, вмикання або вимикання яких здійснюється за заданою програмою. Досліджується можливість використання розробленої гідроударної установки для обертання ковшовоъ гідротурбіни і виробництва електроенергії. Широке впровадження гідроударних електростанцій підвищеної потужності дозволить назавжди позбутися від використання дорогих енергоносіїв та зберегти в чистоті середовище проживання людини.

To plan for timely reconstruction, modernization, repairs or replacement of equipment it is important to reliably predict the instant of its transition to the limiting state that determines the lifetime. Currently, there are no regulatory methods for assessing the lifetime of hydraulic turbines at the operation stage. The approach presented in this paper uses the fracture mechanics methods to build a long-term individual forecast of the dangerous development defects in the main elements of hydraulic turbines taking into account design, technological and operational features. The forecast is based on three-dimensional mathematical models that describe the change in the technical condition of the equipment during time under actual operation. The ANSYS software is used for calculations. Models take into account the size and position of detected or possible defects. Crack growth is determined by the combination of low- and high-frequency loads. The critical length of the crack corresponds to the instant of change of the crack development mechanism, when the failure risk increases sharply. Proposed approach can significantly reduce the possibility of unplanned or emergency shutdown of the hydraulic unit due to its destruction during the overhaul period.

A two-phase hydraulic turbine’s performance and flow field were predicted under different Inlet Gas Volume Fractions (IGVF) with incompressible and compressible models, respectively. The calculation equation of equivalent head, hydraulic efficiency, and flow loss considering the expanding work of compressible gas were deduced based on the energy conservation equations. Then, the incompressible and compressible results, including the output power and flow fields, are compared and analyzed. The compressible gas model’s equivalent head, output power, and flow loss are higher than the incompressible model, but the hydraulic efficiency is lower. As the IGVF increases, the gas gradually diffuses from the blade’s working surface to its suction surface. The gas–liquid separation happens at the runner outlet in the compressible results due to the gas expansion. The area of the low-pressure zone in the incompressible results increases with the IGVF. However, it decreases with the IGVF in the compressible results. As the gas expands in the blade passage, it takes up more flow area, causing the high liquid velocity in the same passage. The runner’s inlet gas distribution affects the liquid flow angle, causing the inlet shock and high TKE areas, especially in the blade passage near the volute tongue. The high TKE area in the compressible results is larger than the incompressible results because the inlet impact loss and the liquid velocity in the blade passage are higher. This paper provides a reference for selecting gas models in the numerical simulation of two-phase hydraulic turbines.

Orientador: Lubienska Cristina Lucas Jaquiê Ribeiro Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Tecnologia Resumo: Uma das principais tarefas de controle numa Usina Hidrelétrica é a regulação das máquinas hidráulicas. Seu monitoramento faz-se necessário para garantir e estabelecer regras operacionais seguras para a instalação. A turbina é um dos elementos básicos de uma Usina Hidrelétrica e o regulador tipo PID é um dos tipos usados para sua regulação. Os parâmetros do regulador da turbina hidráulica são muito estudados, inclusive verificando seu comportamento através da simulação computacional. As simulações computacionais são ferramentas de análise muito úteis e que permitem encontrar a melhor solução que proporcione o melhor desempenho do sistema estudado. Este trabalho apresenta uma metodologia para otimização das constantes do regulador tipo PID de turbina hidráulica utilizando um modelo de simulação aliado a técnicas atuais de otimização evolutiva baseada nos Algoritmos Genéticos. Os exemplos avaliados mostraram significativa melhora nos valores dessas constantes, mostrando a eficácia do uso dessa ferramenta na área da Hidráulica e possibilitando estudos futuros Abstract: One of the main tasks of control in a Hydroelectric Power Plant is the hydraulic machines regulation. Its monitoring becomes necessary to guarantee and to establish safe operational rules for the installation. The turbine is one of the basic elements of the Hydroelectric Power Plant and the PID governor is one of the types used to its regulation. The governor parameters of the hydaulic turbine are studied, also verifying its behavior through the computational simulation. The computational simulations are very useful analysis tools to find the best solution to provide the best performance of the studied system. This work presents a methodology to optimize the PID governor parameters of the hydraulic turbine using a simulation model ally the current techniques of evolutionary optimization based in the Genetic Algorithms. The evaluated examples had shown significant improvement in the constants values, showing the effectiveness use of this tool in the hydraulic area and making possible future studies Mestrado Tecnologia e Inovação Mestre em Tecnologia

Industrial hydraulic turbines, a kind of small-scaled turbine in a more compact and flexible application, are frequently used in hydrogen cracking, synthesis ammonia, and circulating water field. Besides the energy recovery efficiency, the working stability at variable speed situations is a critical issue, since its rotation speed changes with the flow parameters of the upstream. In this paper, a conventional turbine was numerically investigated under three different rotation speeds and its best efficiency points (BEPs). The velocity profiles, blade load, pressure fluctuation, and vibration features were discussed to form a comprehensive evaluation of turbine stability. The numerical results were validated through turbine external characteristic and vibration tests. The results indicate that the pressure pulsation and vibrations increase when it deviates from the rated rotation speed, but the relatively low flowrate point behaves better than the large point in the aspect of turbine stability, the main reasons are the angle of incidence and rotor circumferential vortex. The conclusions can provide significant reference for turbine hydraulic optimization and engineering application.

Целью дипломного проекта является проектирование проточной части гидротурбины на основе Ð¸ÑÑ Ð¾Ð´Ð½Ñ‹Ñ Ð´Ð°Ð½Ð½Ñ‹Ñ . Сначала выберите размер и модель гидротурбины через Ð¸ÑÑ Ð¾Ð´Ð½Ñ‹Ðµ данные. По максимальному и минимальному напору, мы выбрали радиально-осевую гидротурбину PO230.Тогда пройдите универсальная Ñ Ð°Ñ€Ð°ÐºÑ‚ÐµÑ€Ð¸ÑÑ‚Ð¸ÐºÐ° гидротурбины РО 230/833-в-63, мы выбрали расчетную точку для определения диаметра рабочего колеса гидротурбины и частоты вращения гидротурбины. По средством расчета выбора и соответствующего анализа условий эксплуатации строится исчерпывающая Ñ Ð°Ñ€Ð°ÐºÑ‚ÐµÑ€Ð¸ÑÑ‚Ð¸Ñ‡ÐµÑÐºÐ°Ñ кривая работы гидравлической гидротурбины. При условии удовлетворения выбранной конструкции была, выполнена гидравлическая конструкция спиральной камеры гидротурбины, выбран профиль лопатки направляющего аппарата и определены его силовые Ñ Ð°Ñ€Ð°ÐºÑ‚ÐµÑ€Ð¸ÑÑ‚Ð¸ÐºÐ¸, конструкция отсасывающей трубы и очертания проточной части в области рабочего колеса. гидротурбина была нарисована, включая ÑÑ ÐµÐ¼Ñƒ разреза гидротурбины. Затем путем расчетов и анализа делается вывод, что модель гидравлической гидротурбины PO230 возможна. В Ð¿Ñ€ÐµÐ´ÐµÐ»Ð°Ñ Ð´Ð¾Ð¿ÑƒÑÑ‚Ð¸Ð¼Ð¾Ð³Ð¾ диапазона погрешности по Ð¸ÑÑ Ð¾Ð´Ð½Ñ‹Ð¼ данным，строится исчерпывающая Ñ Ð°Ñ€Ð°ÐºÑ‚ÐµÑ€Ð¸ÑÑ‚Ð¸Ñ‡ÐµÑÐºÐ°Ñ кривая работы гидравлической гидротурбины. По Ñ Ð°Ñ€Ð°ÐºÑ‚ÐµÑ€Ð¸ÑÑ‚Ð¸Ñ‡ÐµÑÐºÐ¾Ð¹ кривойможно построить теоретическую модель гидротурбины PO 230. Этот проект в основном выполнил проектную задачу и достиг ожидаемой цели проектирования, The purpose of the thesis project is to design the flow part of a water turbine based on the input data. First select the size and model of the water turbine through the input data. According to the maximum and minimum head, we chose the radial-axial hydraulic turbine PO230.Then pass the universal characteristic of the hydraulic turbine RO 230/833-v-63, we chose the design point to determine the diameter of the impeller of the hydraulic turbine and the speed of the hydraulic turbine. By means of the calculation of the choice and the corresponding analysis of operating conditions, an exhaustive characteristic curve of the hydraulic turbine operation is built. The hydraulic design of the spiral chamber of the turbine has been made, the profile of the guide vane has been selected and its power characteristics, the design of the suction pipe and the outline of the flow part in the area of the impeller have been determined. the hydraulic turbine has been drawn, including the sectional diagram of the turbine. It is then concluded by calculation and analysis that the PO230 hydraulic hydraulic turbine model is feasible. An exhaustive characteristic curve of the operation of the hydraulic turbine is constructed within the allowable error range of the input data. It is possible to build a theoretical model of the hydraulic turbine PO 230 on the basis of the characteristic curve. This project has basically fulfilled the design task and achieved the expected design goal.

Tema ovog rada je numeričko istraživanje interakcije malih vodnih turbina i dinamike riječnog korita pomoću računalne dinamike fluida. Strujanje vode iza turbine je turbulentno i utječe na sedimentno dno rijeke, što može imati značajan utjecaj na ekosustav rijeke, ali i na stabilnost podvodnih struktura, zbog čega su potrebna daljnja istraživanja. U ovom radu korištene su jednadžbe za opisivanje strujanja i interakcije strujanja fluida sa sedimentom i slobodnom površinom, pomoću foam-extend-a. Proučavana je aksijalna turbina s tri lopatice, a simulacije su provedene za četiri konfiguracije turbina u kanalu: • jedna turbina na sredini kanala, • dvije turbine postavljene koaksijalno na sredini kanala, udaljene za 4dt , • dvije turbine postavljene koaksijalno na sredini kanala, udaljene za 7dt , • dvije turbine postavljene jedna uz drugu kraj bočne strana kanala. Rezultati simulacija uspoređeni su međusobno i s dostupnim rezultatima eksperimenata Računalna dinamika fluida može preuzeti značajnu ulogu u proučavanju utjecaja turbina na morfologiju dna, jer uvelike pojednostavljuje i olakšava proučavanje ove problematike. Scope of this Thesis is numerical investigation of interaction between small hydraulic turbines and river sediment dynamics. Water flow behind turbines is turbulent and affects sediment river bed, which can have significant influence on the river ecosystem, but also on underwater structures stability, and further investigation is needed. In this Thesis equations that describe fluid flow and interaction between fluid and sediment river bed and free surface are used, together with foam-extend. Axial turbine with three blades is observed, and simulations were performed for four configurations of turbines in the channel: one turbine in the centre of the channel, two coaxial turbines, in the centre of the channel, with 4dt distance, two coaxial turbines, in the centre of the channel, with 7dt distance, two turbines positioned side by side, near the channel side. The simulation results were compared mutually and with the available experimental data. Computational Fluid Dynamics can play a significant part in investigation of turbine and river morphology interactions, making the analysis of given problems easier and simpler.

Для распознавания состояния гидроагрегата в условиях ограниченной информации, полученной в процессе его эксплуатации, используются различные подходы. При обнаружении или прогнозировании неисправного состояния необходимо провести корректировку настроек в системе управления агрегатом. Традиционно для регулирования гидротурбин используются системы автоматического управления, включающие в себя ПИД-регуляторы. Регулятор сообщает рабочим органам гидротурбины управляющее воздействие, получаемое из сигнала рассогласования. В настоящей работе при разработке адаптивного регулятора гидротурбины использовались нейросетевые методы. В статье приводятся результаты разработки и модельных испытаний адаптивного регулятора гидроагрегатас нейросетевым блоком. Полученные результаты демонстрируют эффективность настройки коэффициентов ПИД-регулятора с помощью нейронной сети. Недостатком разработанной системы регулирования является необходимость многократного изменения уставки при настройке коэффициентов. Предложены направления дальнейшей работы по совершенствованию регулятора., Various approaches are used to recognize the condition of a hydraulic turbine with limited information obtained during its operation. If a faulty condition is detected or predicted, it is necessary to adjust the settings in the control system of the hydraulic turbine. Traditionally, automatic control systems that include PID controllers are used to regulate hydraulic turbines. The controller transmits the control action derived from the error value to the operating assemblies of the hydraulic turbine. In this article, neural network methods were used to develop an adaptive hydraulic turbine controller.The article presents the results of development and model tests of adaptive controller, which includes a neural network unit.The obtained results demonstrate the efficiency of PID controller coefficients adjustment using a neural network.The disadvantage of the developed control system is the multiple setpoint changes during coefficient tuning. The directions of further work to improve the controller are suggested., Приборы и системы. Управление, контроль, диагностика, Выпуск 5 2021

This work is devoted to the analysis of a mathematical model of hydropower unit, consisting of synchronous generator, hydraulic turbine, and speed governor. It is motivated by the accident happened on the Sayano-Shushenskaya hydropower plant in 2009 year. In the analysis we follow the line of classical control theory approach developed in the works of famous scientists J.C. Maxwell, I.A. Vishnegradsky, A.A. Andronov, and F. Tricomi for the study of centrifugal turbine governor and electrical machines limit-load problem. It is shown that the occurrence of vibrations in the Sayano-Shushenskaya hydropower plant can be caused by nonlinear dynamics of the closed-form model. peerReviewed

In a time of rising climate change crises there is a more pressure than ever to find effective energy harvesting method in order to secure our future. In today’s word automobile sectors are introducing new technologies to run vehicles with the help of electricity. Objective of this project is to create self-sustainable system to generate electricity. Converting kinetic and pressure energy of flow of water which runs the turbine assembly couple to generator sequentially located in the channel of water. Water flow in the domestic pipes as kinetic energy has that potential to generate electricity for use and storage purposein addition to perform routine activities such as a laundry, cook, bath etc. In this project, The high water pressure and flow inside the pipe from utility main tank that use for those usual routine activities is also using to rotate small scale hydro-turbine which is attached to pipeline at calculated required height to drive generator for electrical power generation. This project is one step towards generating clean and renewable hydro energy. Paper describes development of Pico hydro generation system and efficient utilization of water energy. Hence, this project is conducted to develops a hydro-generation system using consumed water distributed to houses has an alternative energy source for residential use. The generated power will be stored in the battery sources for the future use which will also satisfies the domestic needs. This project is implemented under the sort of environmental condition where the velocity of water flow ishigher.

This paper presents the data obtained from the CFD simulation of a pico-hydraulic turbine designed for electric power generation in residential units. Pico-hydro turbine systems are a booming option that seeks to take advantage of small waterfalls and/or streams to generate electricity in a clean way. The data collection process was carried out through simulations developed to a model created in SolidWorks, with the help of the ANSYS CFX software in which the solver configuration was adjusted to the parameters suggested by the manufacturer's manuals (ANSYS) and the boundary conditions were determined based on the current regulatory standards for drinking water systems for Colombia. These boundary conditions influence the operation of the turbine, which is why three runs were carried out corresponding to three points of operation and to obtain the output pressure, the fall of the turbine and the hydraulic power that the device would utilise. The data, acquired in a strict manner, offers potential support for further research in the area and the possible manufacture of prototypes. It also encourages the development of simulations and laboratory tests of this type of device in which geometric factors or operating conditions could be modified.

Integrating vertical-axis runners into ball valves for energy harvesting from pressurized pipes in water supply systems has become a promising scheme of self-supplying power (referred to as the &ldquo, GreenValve&rdquo, scheme). In addition to energy harvesting, the GreenValve configuration also has the function of fluid regulating, which makes a qualitative breakthrough in both structure and function. However, the runner specially used to match the ball valve has not been fully studied and designed. Hence, based on the traditional Savonius rotor, a modified semi-elliptical runner is proposed in this study. To better match the ball valve structurally, the roundness of the runner at blade tip position is improved and, thus, the initial runner configuration is obtained. Moreover, research on blade profile flatness and runner aspect ratio is conducted in FLUENT software to be more functionally compatible with the ball valve. Numerical results indicate that the GreenValve always performs best in terms of shaft power at 25% opening regardless of the aspect ratio and the flatness. When the flatness value is equal to 0.7, the GreenValve presents the maximum shaft power and the second highest flow coefficient which is only 1.9% lower than the maximum value. Comparison results of three models with different aspect ratios reveal that the model with the smallest aspect ratio has a slight reduction in flow capacity while a significant improvement in shaft power, reaching a maximum shaft power of 78.6W.

Worldwide electricity generation is featured by the growth of intermittent renewable energies. In this context, hydropower plays a fundamental role because it provides flexibility to the power grid and ensures its stability. The new grid requirements have led hydropower units to working under a wider range of loads and with more start/stop sequences. Pelton turbines are the most suitable for high heads and have a large regulation capacity. In operation, the runner is impinged by high-speed water jets, and, thus, subjected to strong pulsating forces. As a consequence, the structure presents large deformations and high stresses, especially on the buckets. This situation can be much aggravated if the frequency and shape of the excitation is resonant with those of the structure. Therefore, the modal response of the turbine must be thoroughly studied and the most dangerous frequencies avoided. In this paper, a detailed analysis of the modal behavior of Pelton turbines is presented. Four prototypes have been studied for such purpose. The first one has been modeled numerically and analyzed experimentally. Following a systematic investigation, the effect on the modal shapes and the frequencies of the different parts comprising the turbine has been evaluated. The single bucket and the whole runner have been studied. Finally, another turbine installed in the same power plant has been analyzed to determine the effect of the mechanical design on the frequencies. In addition, two prototypes belonging to other power plants have been studied to see the effects of the hydrodynamic design on the modal behavior.

Тема выпускной работы «Установка гидротурбин на трубопроводы с избыточным давлением». В настоящее время мегаполисы, крупные и малые города, деревни и села, промышленные и сельскохозяйственные предприятия в разных географических точках света нуждаются в стабильной, доступной по цене и экологичной энергии. Гидравлические турбины, устанавливаемые в напорные трубопроводы, могут обеспечить потребителей как в частных домашних хозяйствах, так и в промышленной сфере, транспорте и снабжении малых населенных пунктов. В связи с этим, расчет, конструирование и эксплуатация подобного рода гидравлических турбин, обеспечивающих повышение технического и экономического потенциалов гидроэнергетики малых каналов, напорных трубопроводов и гидротехнических сооружений, снижающих капитальные затраты на возведение плотин и восстановление ранее существовавших малых ГЭС, ускоряющих решение проблемы электроснабжения отдаленных локальных потребителей, а также снижающих нагрузку на объединенные электросети – это перспективное направление развития малой энергетики. В работе рассмотрены современные решения, связанные с применением турбин для напорных трубопроводов, учитывающие современный мировой опыт конструирования и эксплуатации гидравлических машин данного типа. Приведены характеристики и описания конструкций агрегатов, рассмотрена экономическая составляющая изготовления агрегата., The theme of the master's thesis is “Installing hydraulic turbines on pipelines with overpressure”. Currently, megacities, large and small cities, villages and villages, industrial and agricultural enterprises in different geographic points of the world need stable, affordable and ecological energy. Hydraulic turbines installed in pressure pipelines can provide consumers both in private households and in the industrial sphere, transport and supply of small settlements. In this regard, the calculation, design and operation of such kind of hydraulic turbines, providing increased technical and economic potentials of hydropower of small channels, pressure pipelines and hydraulic structures, reducing capital costs for the construction of dams and restoration of existing small hydropower plants, accelerating the solution of the problem of power supply to remote local consumers, as well as reducing the load on the united power grids - this is a promising direction for the development of small energy. The paper discusses modern solutions related to the use of turbines for pressure pipelines, taking into account modern world experience in the design and operation of hydraulic machines of this type. The characteristics and descriptions of the design of the units are given, the economic component of the manufacture of the unit is considered.

Данная работа посвящена исследованию двух вариантов технической части проекта по реконструкции ГЭС Нива-2, предусматривающего строительство нового станционного узла для дополнительного агрегата. На основе практических и методических рекомендаций в работе был проведён выбор основных параметров двух типов гидротурбин по их номенклатурным универсальным характеристикам. Сделано сравнение полученных данных и выбран оптимальный вариант оборудования по энергетическим параметрам, кавитационным качествам и объёмам работ на модернизацию. Построены эксплуатационные характеристики выбранных гидротурбин, проведены расчёты основных элементов проточной части и построены эскизы спиральных камер со статором, рабочих колёс, лопаток направляющего аппарата с его кинематической схемой и отсасывающих труб. На основе этих эскизов построены общие эскизы проточных частей, а также построены параметрические 3D-модели выбранных ГТ в программном комплексе SolidWorks. На основании полученных результатов можно проводить дальнейшее уточнение характеристик и выбор вспомогательного оборудования, можно оценить прочностные характеристики агрегата, разработать технические решения по компоновке гидрогенерирующего оборудования в составе ГУ., The given work is devoted to the research of two options for the technical part of the project for the reconstruction of the Niva-2 hydroelectric power station, which provides for the construction of a new station for an additional hydraulic unit. Based on practical and methodological recommendations, a selection was made of the main parameters of two types of hydraulic turbines according to their nomenclature universal characteristics. A comparison of the data obtained is made and the optimal equipment option is selected according to energy parameters, cavitation qualities and the amount of modernization work. The operational characteristics of the selected hydraulic turbines were built, the main elements of the flow part were calculated, and sketches of the spiral chamber with a stator, vanes of the guide apparatus with a kinematic scheme, an impeller, and a suction pipe were constructed. Based on these sketches, a general sketch of the flow passage was built, as well as its parametric 3D model in the SolidWorks software package. Based on the results obtained, it is possible to further refine the characteristics and the choice of auxiliary equipment, you can evaluate the strength characteristics of the unit, develop technical solutions for the layout of the hydro-generating equipment as part of the hydroelectric complex.

На гидроэлектростанциях с высоким напором, использующих энергию горных рек широко применяются гидротурбины радиально-осевого типа. Как правило, из-за высокой концентрации взвешенных наносов в горных реках, ресурс гидротурбин данного типа определяется в основном фактором эрозионного износа. Как при новом строительстве, так и при проведении реконструкций и модернизаций таких ГЭС с установкой нового оборудования, важно учесть опыт предыдущей эксплуатации подобных энергообъектов. В работе применяется метод численного моделирования двухфазного течения в высоконапорной радиально-осевой гидротурбине малой быстроходности для оценки плотности эрозионного износа лопастей рабочего колеса по модели Табакова-Гранта на разных режимах работы с разным расходом наносов в потоке. Показано, что величина эрозионного износа в основном связана с величинами местных скоростей потока, наиболее повреждаемыми областями является входная и выходная кромки лопасти, а также сторона давления лопасти. Подтверждено, что величина плотности эрозионного износа имеет прямую линейную зависимость от величины расхода наносов, поступающих в проточную часть гидротурбины. Определено, что в данных условиях применение нержавеющей стали вместо обычной углеродистой может не сказаться гарантированно в лучшую сторону на времени между капитальными ремонтами и, как следствие, объеме выработки электроэнергии ГЭС., Francis turbines are a common solution for high head hydraulic power plants using mountain rivers energy. Due to a high concentration of sediments in such rivers, a lifetime of hydraulic turbines of this type is determined mainly by erosion wear factor. Considering previous operation experience of power plants of this type is important in new construction or reconstruction, modernization of hydraulic power plants and installation of new equipment. The article presents the numerical simulation analysis of a two-phase flow in a high head Francis turbine operating at a low specific speed to evaluate erosion wear of runner blades using Tabakoff-Grant model at various operating modes and sediment mass flow rates. We show that the value of erosion wear is mainly associated with the values of local flow rates, the most damaged areas are the leading and trailing edges of the blade, as well as the pressure side of the blade. The results confirm the linear dependence of Francis turbine runner blade erosion on the amount of sediments. We determined that the new hydraulic equipment made of stainless steel instead of regular carbon cast steel may not sufficiently increase intervals between overhauls.

The issues of reliability and operation safety of power equipment, including hydraulic units of hydropower plants, are becoming more and more relevant with the increasing the service life. The long operation period and the individual characteristics of hydraulic units do not allow to apply outside the design lifetime the methodology for assessing the technical condition based only a simple extrapolation of the results of previous surveys. The integrated approach that combines application of modern diagnostic systems capabilities and achievements of computing technologies, the generalization of theoretical experience and the results of numerous experimental investigations using model and full-scale hydraulic units makes it possible to reliably and reasonably predict changes in the technical condition of hydraulic units, not allowing to reduce the reliability and safety below acceptable level. The material of this article was partially presented at the round table "Siberia Hydropower Development" at the VII Siberian energetic forum in 2016.

Due to the S-shape characteristics and the complicated flow in pump turbine, there may be serious instability when the pump-storage power plant starts. In order to conduct further study on the energy dissipation in hydraulic turbine, three dimensional incompressible steady state simulations were applied using SST k-ω turbulence model in this paper. It can be seen that the simulation results are consistent with experimental results well by the comparison of characteristic curves, and further analyses were made based on the entropy production theory. It is shown that the entropy production of spiral casing accounts for the minimum proportion in all components. The entropy production of cascades and runner differs a lot at different guide vane openings, and it features “S” characteristics with the increase of discharge. Then, the analysis of entropy production distribution on runner, blade cascades and draft tube was carried out at the 10mm guide vane opening. It was found that the losses in guide vane space is much higher than that of stay vane space and the losses are mainly in the tail area of stay vanes and vaneless space. The losses mainly occurs in the leading edges and the trailing edges of blades. The largest losses mainly lie at the wall of straight cone near the inlet in draft tube. The losses at the inner surface of elbow are also very high. The results indicate that the method based on the entropy production theory is very helpful to analyze and locate the losses in hydraulic turbine.

To assess the fulfillment of contract conditions for the equipment delivery, determining the properties and capabilities of a generating unit or some part of it, the measurements carried out under real operating conditions were necessary. In this paper, the results of the test that was carried out in a small hydropower plant (SHPP), aimed at determining the relative efficiency of the hydraulic turbine and its comparison with the guaranteed values, are presented. The dependence of the turbine efficiency on the turbine discharge was determined based on the test results, using the index method. The test was performed at one net head.

The paper presents methodology used for determining the efficiency of a low head Kaplan hydraulic turbine with short converging intake. The measurement method used was the current meters method, the only measurement method recommended by the IEC 41standard for flow measurement in this case. The paper also presents the methodology used for measuring the flow by means of the current meters method and the various procedures for calculating the flow. In the last part the paper presents the flow measurements carried out on the Fughiu HPP hydraulic turbines for determining the actual operating efficiency.

Distillation for R-410A reclamation from a waste refrigerant is an energy-intensive process. Thus, various heat pump configurations were proposed to enhance the energy efficiency of existing conventional distillation columns for separating R-410A and R-22. One new heat pump configuration combining a vapor compression (VC) heat pump with cold water and hot water cycles was suggested for easy operation and control. Both advantages and disadvantages of each heat pump configuration were also evaluated. The results showed that the mechanical vapor recompression heat pump with top vapor superheating saved up to 29.5%, 100.0%, and 10.5% of the energy required in the condenser duty, reboiler duty, and operating cost, respectively, compared to a classical heat pump system, and 85.2%, 100.0%, and 60.8%, respectively, compared to the existing conventional column. In addition, this work demonstrated that the operating pressure of a VC heat pump could be lower than that of the existing distillation column, allowing for an increase in capacity of up to 20%. In addition, replacing the throttle valve with a hydraulic turbine showed isentropic expansion can decrease the operating cost by up to 20.9% as compared to the new heat pump configuration without a hydraulic turbine. Furthermore, the reduction in carbon dioxide emission was investigated to assess the environmental impact of all proposed sequences.

Erosive wear of hydraulic machines is a common issue, which results in efficiency degradation, the enhancement of cavitation, and the need for expensive maintenance. Although numerical simulations of the erosion process could be very useful, both for understanding and predicting the process, its multiscale nature renders it very difficult to simulate. A previously validated multiscale model of erosion is presented. It consists of two coupled sub-models: On the microscale, the sediment impacts are simulated by means of comprehensive physical models, on the macroscale, the turbulent sediment transport and erosion accumulation are calculated. A multiscale simulation of the erosion of a prototype-scale Pelton bucket impacted by a sediment-laden water jet is presented. The simulation results, namely the erodent flux and the distributions of average impact angle and velocity on the bucket surface, bring insight into the erosion process. Furthermore, the results explain the obtained erosion distribution, which is in very good agreement with the experimental erosion measurements available in the literature for the same test case.

Submitted by Ronald Eder Chávez Palomino (ronald.chavez.p@uni.pe) on 2019-04-09T15:49:38Z No. of bitstreams: 1 Controlador híbrido PID-fuzzy baseado na inferência Takagi-Sugeno para a regulação de tensão e de frequência.pdf: 13964913 bytes, checksum: ed001d4c4dc86a38bbc39317f1bfe58f (MD5) Approved for entry into archive by Cristina Alexandra de Godoy null (cristina@adm.feis.unesp.br) on 2019-04-09T20:19:15Z (GMT) No. of bitstreams: 1 chavezpalomino_re_me_ilha.pdf: 14218476 bytes, checksum: b01e68c51de4353dd05a21f767e5dd90 (MD5) Made available in DSpace on 2019-04-09T20:19:15Z (GMT). No. of bitstreams: 1 chavezpalomino_re_me_ilha.pdf: 14218476 bytes, checksum: b01e68c51de4353dd05a21f767e5dd90 (MD5) Previous issue date: 2019-02-12 Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Nesta pesquisa apresentam-se os principais conceitos gerais de estabilidade elétrica, assim como suas divisões e classificações, onde são desenvolvidas as condições de operação de um sistema elétrico de potência, que são relevantes nos estudos de estabilidade angular do rotor, tensão e frequência. Para os estudos de estabilidade da frequência e de tensão é preciso conhecer os equipamentos como os reguladores de tensão e frequência, em consequência é apresentada a modelagem matemática de vários componentes dinâmicos como o sistema de excitação, estabilizador do sistema de potência (PSS), sistema de regulação de velocidade, sistema de regulação de tensão (AVR), máquina síncrona, turbina a vapor e turbina hidráulica. É necessário a modelagem de eles para projetar seus respectivos controladores. Nesta pesquisa também se faz a introdução ao controlador Fuzzy e controlador PID convencional assim como os métodos de sintonia, depois projetamos um controlador que combine os dois controladores e tenha mais vantagens como o controlador híbrido PID-Fuzzy. Depois de desenvolver a modelagem do regulador de tensão e frequência, fazemos o projeto do controlador PID-Fuzzy, previamente projetado o controle PID. As simulações dos sistemas de regulação de tensão e frequência sem controlador, com controlador PID e com controlador PID-Fuzzy foram realizadas aplicando a ferramenta computacional de Matlab-Simulink no domínio do tempo contínuo e as respostas foram investigadas e discutidas. This research presents the main general concepts of electrical stability, as well as their divisions and classifications, where the operating conditions of an electrical power system are developed, which are relevant in the studies of angular stability of the rotor, voltage and frequency. For frequency and voltage stability studies it is necessary to know equipment such as voltage and frequency regulators, consequently the mathematical modeling of several components is presented as dynamic as the excitation system, power system stabilizer (PSS) , speed regulation system, voltage regulation system (AVR), synchronous machine, steam turbine and hydraulic turbine. We need the modeling of them to design their respective controllers. In this investigation we also do the introduction to the Fuzzy controller and conventional PID controller as well as the tuning methods then we designed a controller that combines the two controllers and has more advantages as the hybrid PID-Fuzzy controller. After developing the modeling of the voltage and frequency regulator, we design the PID-Fuzzy controller, previously designed the PID control. The simulations of the voltage and frequency regulation systems without controller, with PID controller and with PID-Fuzzy controller were performed applying the Matlab-Simulink computational tool in the continuous time domain and the answers were investigated and discussed. CAPES: Código de financiamento 001

Воронин Сергей Григорьевич, д-р техн. наук, профессор кафедры «Летательные аппараты», ЮжноУральский государственный университет, г. Челябинск; voroninsg@susu.ru. Давлатов Азамджон Махмадиевич, аспирант кафедры «Летательные аппараты», Южно-Уральский государственный университет, г. Челябинск; davlatov_azam@bk.ru. Султонов Оламафруз Олимович, аспирант кафедры «Летательные аппараты», Южно-Уральский государственный университет, г. Челябинск. Косимов Бахтиёр Исматуллович, аспирант кафедры «Летательные аппараты», Южно-Уральский государственный университет, г. Челябинск. Гулов Диловар Юсупович, аспирант кафедры «Летательные аппараты», Южно-Уральский государственный университет, г. Челябинск. S.G. Voronin, voroninsg@susu.ru, A.M. Davlatov, davlatov_azam@bk.ru, O.O. Sultonov, B.l. Kosimov, D.Yu. Gulov South Ural State University, Chelyabinsk, Russian Federation Представлен краткий анализ существующих малых ГЭС Республики Таджикистан. В результате анализа проблем, усложняющих эксплуатацию мини-ГЭС, отмечены элементы, не позволяющие их использовать в автономном режиме и снижающие надёжность работы. Предлагается для обеспечения надёжной работы мини-ГЭС и возможности эксплуатации в необслуживаемом режиме строить её на основе конструктивно простых и надёжных устройств. При этом появляется возможность отказаться от непрерывного наблюдения за работой мини-ГЭС обслуживающим персоналом и обойтись периодическими регламентными проверками. В качестве турбины предлагается использовать центробежный насос, не нуждающийся в дополнительных операциях управления рабочими режимами, а в качестве генератора - синхронную машину с возбуждением от постоянных магнитов, не требующую наличия канала организации и регулирования потока возбуждения. Качество вырабатываемой энергии предлагается обеспечить с помощью полупроводникового преобразователя напряжения, который должен осуществлять стабилизацию с заданной точностью частот и амплитуд входного напряжения мини-ГЭС. В состав мини- ГЭС предлагается ввести устройства для самодиагностики, осуществляющие контроль не только качества входного напряжения, но и состояние основных элементов мини-ГЭС - турбин, преобразователя напряжений, коммутационной аппаратуры и устройства связи с центральным диспетчерским пунктом. В статье показаны также проблемы, возникающие при реализации предлагаемой структуры, касающиеся в основном обеспечения симметрирования входного напряжения при существенно несимметричной нагрузке, а также повышения достоверности и надёжности устройств диагностики состояния отдельных элементов мини-ГЭС и пути их решения. The article briefly analyzes the existing small hydropower plants in the Republic of Tajikistan. Analysis reveals why such units are not suitable for stand-alone operation and what renders them less reliable. The paper proposes a simpler design for better reliability and stand-alone, low-maintenance operation. A design based on simpler and more reliable components requires less maintenance, which could be limited to regular inspections, hence no need for round-the-clock staff presence. A centrifugal pump is proposed as a turbine, as it does not require additional parameter controls, while a synchronous permanent magnet-excited unit is proposed as a generator, as it does not require a special channer to control the excitation flux. For better quality of generated electricity, the paper proposes using a semiconductor-based voltage converte that will stabilize the input voltage to a required accuracy of frequency and amplitude. Self-diagnosis instrumentation is part of the design, as it can monitor not only the input voltages, but also the condition of primary components: turbines, voltage converters, switches, and communications with the mission control center. The paper also analyzes the problems of implementing this design, which mainly pertain to balancing the input voltage given a significantly asymmetrical load; another challenge is to improve the accuracy and reliability of instrumentations implemented to monitor the health of specific small-HPP elements.

Рассмотрены достоинства и недостатки, пути решения существующих проблем, а также перспективы развития приливных электростанций., The advantages and disadvantages, solutions to existing problems, as well as pro-spects for the development of tidal power plants are considered.

Submitted by Gustavo De Almeida Rodrigues Teixeira (gustavoteixeira@id.uff.br) on 2019-02-04T01:21:53Z No. of bitstreams: 1 Dissertação_Gustavo AR Teixeira.pdf: 2228338 bytes, checksum: 596e9f552f11bf85d69cb18bdb1f0968 (MD5) Approved for entry into archive by Ana Cristina Figueiredo Loureiro (ana-cristina.loureiro@unesp.br) on 2019-02-04T18:06:01Z (GMT) No. of bitstreams: 1 Dissertação_Gustavo AR Teixeira.pdf: 2228338 bytes, checksum: 596e9f552f11bf85d69cb18bdb1f0968 (MD5) Made available in DSpace on 2019-02-04T18:06:01Z (GMT). No. of bitstreams: 1 Dissertação_Gustavo AR Teixeira.pdf: 2228338 bytes, checksum: 596e9f552f11bf85d69cb18bdb1f0968 (MD5) Previous issue date: 2018-12-14 A busca por estudos visando às melhorias em projetos de engenharia relacionados às turbinas hidráulicas se tornam cada vez mais essenciais considerando a crescente demanda por fontes de energias renováveis como as usinas hidrelétricas. Por este motivo, cresce a necessidade de estudos sobre turbinas hidráulicas, por meio de inovações tecnológicas, que proporcionem a melhoria do rendimento das mesmas. Esse trabalho tem como objetivo aplicar modificações nas turbinas por meio de técnicas de projeto, como o biomimetismo, nas pás dos rotores de turbinas do tipo Bulbo e comparar o comportamento do escoamento sobre as pás e o rendimento dessas turbinas com aquelas projetadas sem a aplicação do biomimetismo. Para atingir esse objetivo a modelagem da turbulência se dá através da metodologia URANS (unsteady Reynolds averaged Navier-Stokes) e o modelo de turbulência escolhido foi o k-ε, por ser ideal em escoamentos turbulentos, demandar um menor tempo de simulação computacional e apresentar maior semelhança com dados experimentais. Como resultado, observa-se que as mudanças realizadas na geometria das pás das turbinas, baseadas nos conceitos e técnicas de biomimetismo, proporcionaram aumento de desempenho nas turbinas bulbo, evidenciando-se assim a capacidade do biomimetismo de proporcionar melhorias em projetos de turbinas hidráulicas, que ainda é pouco difundida e estudada. Para a realização desse trabalho, usa-se o software comercial SolidWorks® para a criação da geometria e o ANSYS Student® (versão 19.1) para a análise do escoamento utilizando a dinâmica de fluidos computacional (CFD). The search for studies aimed at improving engineering projects related to hydraulic turbines becomes increasingly essential considering the increasing demand for renewable energy sources such as hydroelectric plants. For this reason, the need is growing for studies about hydraulic turbines, by means of technological innovations, that provide the improvement in these turbines. The objective of this work is to apply modifications in turbines by means of design techniques, such as biomimicry, on the rotor blades of the Bulb type turbine, and to compare the flow behavior on the blades and the performance of these turbines with those projected without the application of the biomimetism. To accomplish this objective, turbulence modeling was performed using the URANS (Unsteady Reynolds Averaged Navier-Stokes) methodology and the turbulence model chosen was k-ε, because it is ideal in turbulent flows, requires a shorter computational simulation time and presents greater similarity with experimental data. As a result, changes in turbine blade geometry, based on biomimetic concepts and techniques, have resulted in significant performance gains in bulb turbines, thus demonstrating the ability of biomimetric to provide improvements in hydraulic turbine designs , which is still less widespread and studied. The commercial SolidWorks® software was used for the creation of geometry and the ANSYS Student® (version 19.1) for flow analysis using computational fluid dynamics (CFD)

The determination of the energy characteristics of a double-regulated hydro turbine is based on numerous measuring points during extensive and expensive experimental model tests in the laboratory and on site prototype tests at the hydropower plant. By the spatial interpolation of representative measured points that belong to the so-called on-cam curves for different speed factors, the hill performance diagram is obtained. The focus of the paper is the contemporary method of artificial neural network models use for the prediction of turbine characteristics, especially in not measured operation modes. A part of the existing set of experimental data for the Kaplan turbine energy parameters is used to train three developed neural network models. The reliability of applied method is considered by analysing, testing and validating the predicted turbine energy parameters in comparison with the remaining data.

Abrasive Water Jet Machining (AWJM) is one of the most popular unconventional machining processes used to machine difficult-to-machine materials. Apart from regular cutting, it is also used for turning, threading, slotting, milling, etc. This paper details the experimental investigations on Abrasive Water Jet Pocket Milling (AWJPM) on Titanium (Ti6Al4V) using garnet abrasive. The influence of waterjet pressure, step-over, traverse rate and abrasive mass flow rate were studied on the output responses such as depth of cut and surface roughness (Ra). The experiments were designed using L9 Orthogonal Array and ANOVA analysis helped in determination of significant process. ANOVA analysis on depth of cut indicated that step-over and traverse rate are the most significant process parameters. However, ANOVA analysis for surface roughness (Ra) was inconclusive and the significant process parameters could not be determined.

The purpose of the study is development of a structural scheme of mining-engineering system designed to ensure energy performance of the mine water outflow system. The article reveals the need for research aimed at improving the energy efficiency of the water outflow system by comparing the dynamics of electrical energy consumption and commercial output volume at the mining industry enterprises. A brief overview of the global experience in compensation for growth of electric energy consumption under more difficult mining conditions and mining depth due to the use of innovative technological solutions in the mine water outflow system is given. Scientific novelty of the research is the use of energy, which is bypassed to the underlying horizons of the underground mine, of technological and natural waters to improve efficiency of pumping units by using boost pressure and automated processes of cleaning hydraulic flows from sludge deposits, as well as to reduce the overall operational costs in the water outflow system. The energy-efficient scheme of mine water outflow system that increases energy efficiency of a mining enterprise is substantiated.

Linear elastic fracture mechanics (LEFM) approaches are seldom used to analyze fatigue problems in hydraulic turbomachinery, where extremely simplified fatigue models are normally considered. In one of the largest Kaplan hydraulic turbines in the world, the piston rod, which is an important load transfer component, was found broken twice at the same location. This event, which leads to extremely high direct reparation costs and indirect costs, is a very useful case for research of fatigue problems in hydraulic turbines by means of LEFM. For this purpose, the crack growth progress in the piston rod is simulated with numerical LEFM techniques. A probabilistic model for the initial flaw size is considered. A reliability criterion, consisting in the probability of not having a critical crack or a fracture in the piston rod after a specific service time, is defined. Based on this model, the influence of initial crack models and operating services of the machine on the reliability of the unit is discussed. The calculated crack path and predicted number of loading cycles as a function of the initial crack size agree with the actual fracture section and operating time to fracture.

One of the problems faced by a designer in the modernization of operating generating units is the analysis of the feasibility of ensuring the strength and reliability of turbine parts and components in their further continuous operation under dynamic load or replacement of the turbine parts and components which would by optimal in terms of weight and dynamic behavior. It is possible to solve the above problem using computer technologies for dynamic study of load bearing structures of hydraulic turbines in various operating modes. This paper describes techniques developed to study the dynamic mode of deformation of hydraulic turbine head cover taking up the hydrodynamic pressure acting on its surface in contact with water and the weights of parts and components located on its surface. For the first time, the influence of added water masses of the structure is three-dimensionally considered using mathematical models based on hypersingular equations and combination of the finite element method and boundary element method. Application program packages are developed which are a powerful tool of automation in the determination of dynamic mode of deformation of the hydraulic turbine head cover. Numerical results are obtained allowing the evaluation of the dynamic mode of deformation taking into consideration the effect of water on the cast iron head cover of hydraulic turbine ПЛ 20-В-500 inoperation and subject to replacement as well as that on the welded steel head cover developed to replace the cast iron one. The numerical study is analyzed and recommendations are given for designing of the welded head cover which dynamical behavior allows preventing resonance phenomena and ensuring the operating reliability. The techniques used are validated by the regulatory document «Residual life prediction for water passage components of hydraulic turbines of HPPs and PSPs – Methodical Guidelines» SOU-N MEV 40.1–21677681–51: 2011., Одной из проблем, возникающих перед конструктором при модернизации действующих гидроагрегатов, является анализ возможности обеспечения прочности и надежности узлов и деталей турбины в условиях дальнейшей продолжительной работы под действием динамической нагрузки или их замена, оптимальная как по массе, так и по динамическим характеристикам. Решение этой проблемы возможно с использованием компьютерных технологий для исследования динамики несущих конструкций гидротурбин при разных режимах эксплуатации. В работе описаны методики, разработанные для исследования динамического напряженно-деформированного состояния крышки гидротурбины, которая воспринимает гидродинамическое давление, действующее на ее контактирующую с водой поверхность, а также веса размещенных на ее поверхности узлов и деталей. Впервые в трехмерной постановке учтено влияние присоединенных масс воды конструкции с применением математических моделей, основанных на гиперсингулярных уравнениях и сочетании методов конечных и граничных элементов. Разработаны пакеты прикладных программ, являющиеся мощным инструментом автоматизации при определении динамического напряженно-деформированного состояния крышки гидротурбины. Получены численные результаты, позволяющие оценить динамическое напряженно-деформированное состояние с учетом влияния воды находящейся в эксплуатации и подлежащей замене литой чугунной крышки гидротурбины ПЛ 20-В-500, а также разработанной для ее замены стальной сварной крышки. Выполнен анализ численного исследования и даны рекомендации для проектирования сварной крышки, динамические характеристики которой позволяют исключить резонансные явления и обеспечить эксплуатационную надежность. Примененные методики обоснованы нормативным документом «Розрахунок залишкового ресурсу елементів проточної частини гідротурбін ГЕС та ГАЕС. Методичні вказівки» СОУ-Н МЕВ 40.1 –21677681–51: 2011., Описані методики, розроблені для дослідження динамічного напружено-деформованого стану кришки гідротурбіни, застосування яких обґрунтовано нормативним документом «Розрахунок залишкового ресурсу елементів проточної части гідротурбін ГЕС та ГАЕС. Методичні вказівки» СОУ-Н МЕВ 40.1 -21677681-51:2011. Вперше в тривимірній постановці враховано вплив приєднаних мас води конструкції із застосуванням математичних моделей, що грунтуються на гіперсингулярних рівняннях і поєднанні методів скінченних та граничних елементів. Отримано чисельні результати, що дозволяють оцінити з урахуванням впливу води динамічний напружено-деформований стан литої чавунної кришки гідротурбіни ПЛ 20 В-500, а також розробленої для її заміни конструкції сталевої зварної кришки. Виконано аналіз чисельного дослідження та надано рекомендації для проектування зварної кришки, динамічні характеристики якої дозволяють виключити резонансні явища та забезпечити експлуатаційну надійність

One of the main causes of damage in hydraulic turbines is cavitation. While not all cavitation appearing in a turbine is of a destructive type, erosive cavitation can severely affect the structure, thus increasing maintenance costs and reducing the remaining useful life of the machine. Of all types of cavitation, the maximum erosion occurs when clouds of bubbles collapse on the runner surface (cloud cavitation). When this occurs it is associated with a substantial increase in noise, and vibrations that are propagated everywhere throughout the machine. The generation of these cavitation clouds may occur naturally or it may be the response to a periodic pressure fluctuation, like the rotor/stator interaction in a hydraulic turbine. Erosive bubble cavitation generates high-frequency vibrations that are modulated by the shedding frequency. Therefore, the methods for the detection of erosive cavitation in hydraulic turbines are based on the measurement and demodulation of high-frequency vibrations. In this paper, the feasibility of detecting erosive cavitation in hydraulic turbines is investigated experimentally in a rotating disk system, which represents a simplified hydraulic turbine structure. The test rig used consists of a rotating disk submerged in a tank of water and confined with nearby axial and radial rigid surfaces. The excitation patterns produced by cloud cavitation are reproduced with a PZT (piezoelectric patch) located on the disk. These patterns include pseudo-random excitations of different frequency bands modulated by one low carrier frequency, which model the erosive cavitation characteristics. Different types of sensors have been placed in the stationary and in the rotating parts (accelerometers, acoustic emission (AE), and a microphone) in order to detect the excitation pattern. The results obtained for all the sensors tested have been compared in detail for the different excitation patterns applied to the disk. With this information, the best location and type of sensor to detect the different excitations have been identified. This study permits improving the actual technique of detecting erosive cavitation in hydraulic turbines and, therefore, to avoid operation under these circumstances.

Hydropower plants are of paramount importance for the integration of intermittent renewable energy sources in the power grid. In order to match the energy generated and consumed, Large hydraulic turbines have to work under off-design conditions, which may lead to dangerous unstable operating points involving the hydraulic, mechanical and electrical system. Under these conditions, the stability of the grid and the safety of the power plant itself can be compromised. For many Francis Turbines one of these critical points, that usually limits the maximum output power, is the full load instability. Therefore, these machines usually work far away from this unstable point, reducing the effective operating range of the unit. In order to extend the operating range of the machine, working closer to this point with a reasonable safety margin, it is of paramount importance to monitor and to control relevant parameters of the unit, which have to be obtained with an accurate sensor acquisition strategy. Within the framework of a large EU project, field tests in a large Francis Turbine located in Canada (rated power of 444 MW) have been performed. Many different sensors were used to monitor several working parameters of the unit for all its operating range. Particularly for these tests, more than 80 signals, including ten type of different sensors and several operating signals that define the operating point of the unit, were simultaneously acquired. The present study, focuses on the optimization of the acquisition strategy, which includes type, number, location, acquisition frequency of the sensors and corresponding signal analysis to detect the full load instability and to prevent the unit from reaching this point. A systematic approach to determine this strategy has been followed. It has been found that some indicators obtained with different types of sensors are linearly correlated with the oscillating power. The optimized strategy has been determined based on the correlation characteristics (linearity, sensitivity and reactivity), the simplicity of the installation and the acquisition frequency necessary. Finally, an economic and easy implementable protection system based on the resulting optimized acquisition strategy is proposed. This system, which can be used in a generic Francis turbine with a similar full load instability, permits one to extend the operating range of the unit by working close to the instability with a reasonable safety margin.

Nowadays, hydropower plays an essential role in the energy market. Due to their fast response and regulation capacity, hydraulic turbines operate at off-design conditions with a high number of starts and stops. In this situation, dynamic loads and stresses over the structure are high, registering some failures over time, especially in the runner. Therefore, it is important to know the dynamic response of the runner while in operation, i.e., the natural frequencies, damping and mode shapes, in order to avoid resonance and fatigue problems. Detecting the natural frequencies of hydraulic turbine runners while in operation is challenging, because they are inaccessible structures strongly affected by their confinement in water. Strain gauges are used to measure the stresses of hydraulic turbine runners in operation during commissioning. However, in this paper, the feasibility of using them to detect the natural frequencies of hydraulic turbines runners while in operation is studied. For this purpose, a large Francis turbine runner (444 MW) was instrumented with several strain gauges at different positions. First, a complete experimental strain modal testing (SMT) of the runner in air was performed using the strain gauges and accelerometers. Then, the natural frequencies of the runner were estimated during operation by means of analyzing accurately transient events or rough operating conditions.

International audience; The design of a novel submerged hydraulic turbine for producing electricity by converting the available hydropower on canal locks during raising and lowering ships, but with the minimum overall impact on the facility, is being considered. The hydraulic head in such applications is low (few meters) and varies over time (from its maximum value down to zero) resulting in a low potential conversion of hydraulic head in electrical energy. The study involves the modification of the hydraulic transient system, the design and performance estimation of a hydraulic turbine. Based on the performance curves, a permanent magnet Vernier generator is designed. The models of hydraulic turbine and generator are added to the system model and simulations results of the whole system are presented.

The paper contains analysis the possibility of using hydraulic turbines in water supply systems and shows the design of a research stand for the study of hydraulic turbines for use in water supply systems В работе проанализирована возможность применения гидравлических турбин в водопроводных системах и приведена конструкция исследовательского стенда по исследования гидравлических турбин для работы в водопроводных системах.

[ES] Las necesidades que existen en nuestra sociedad ante la gran dependencia de los recursos energéticos, originan la demanda de nuevas tecnologías que permitan el ahorro y la recuperación de energía (RE). El agua es uno de los mayores recursos naturales que se encuentran disponibles en la naturaleza del cual depende en buena parte la generación de la energía. Por ello, estudiar energéticamente las redes de distribución de agua (RDA), permite identificar las pérdidas que poseen estos sistemas y determinar la energía potencialmente recuperable (EPR) que podría obtenerse a partir de los excesos de energía suministrada a los usuarios. Algunos trabajos presentes en la literatura, han definido el balance energético de los SDA y han caracterizado la EPR como la diferencia entre la energía suministrada a cada nudo de consumo y la energía mínima necesaria. Sin embargo, en el presente trabajo, se propone un nuevo balance energético, distinguiendo dentro del término de EPR, tres términos más. Es decir, la cantidad de energía que se puede recuperar en el sistema tiene su origen en tres puntos: los usuarios, las conducciones de la red en las que pueden instalarse nuevos elementos de RE, y las válvulas de regulación y control que pueden ser sustituidas por pequeñas turbinas. Esta metodología permite obtener el máximo de energía posible que pudiera recuperarse de un sistema de distribución de agua. Para demostrar la validez de la metodología, ésta se aplica a la red de riego de Balerma. Aunque la mayor parte del trabajo se centra en la posible instalación de elementos de RE a nivel de red, el capítulo 4 se dedica a estudiar los diferentes dispositivos que podrían instalarse: diferentes tipos de turbinas hidráulicas convencionales, PATs (del inglés pump as turbines) o incluso dispositivos de recuperación de energía de tipo doméstico. Para profundizar en la caracterización de estos dispositivos se realizan una serie de ensayos de una micro turbina hidráulica, obteniéndose tanto la curva presión-caudal como la curva tensión-caudal. La metodología desarrollada se aplica al caso de la Red Matriz de Bogotá. Esta red presenta una orografía en el terreno que la hacen idónea para recuperar energía de exceso que llegue a los nudos de consumo. Para ello se aplica la metodología y se estudian las diferentes opciones para instalar recuperadores energéticos a nivel de red. Para ello, es necesario realizar un análisis de costes para observar la rentabilidad que ofrecen estas máquinas en función de la energía que son capaces de extraer., [CA] Les necessitats que existeixen en la nostra societat davant la gran dependència dels recursos energètics, originen la demanda de noves tecnologies que permetin l'estalvi i la recuperació d'energia (RE). L'aigua és un dels majors recursos naturals que es troben disponibles a la naturalesa del qual depèn en bona part la generació de l'energia. Per això, estudiar energèticament les xarxes de distribució d'aigua (RDA), permet identificar les pèrdues que tenen aquests sistemes i determinar l'energia potencialment recuperable (EPR) que podria obtenir-se a partir dels excessos d'energia subministrada als usuaris. Alguns treballs presents a la literatura, han definit el balanç energètic dels SDA i han caracteritzat la EPR com la diferència entre l'energia subministrada a cada nus de consum i l'energia mínima necessària. No obstant això, en el present treball, es proposa un nou balanç energètic, distingint dins el terme d'EPR, tres termes més. És a dir, la quantitat d'energia que es pot recuperar en el sistema té el seu origen en tres punts: els usuaris, les conduccions de la xarxa en les que poden instal·lar-se nous elements de RE, i les vàlvules de regulació i control que poden ser substituïdes per petites turbines. Aquesta metodologia permet obtenir el màxim d'energia possible que pogués recuperar-se d'un sistema de distribució d'aigua. Per demostrar la validesa de la metodologia, aquesta s'aplica a la xarxa de reg de Balerma. Encara que la major part de la feina se centra en la possible instal·lació d'elements de RE a nivell de xarxa, el capítol 4 es dedica a estudiar els diferents dispositius que podrien instal·larse: diferents tipus de turbines hidràuliques convencionals, PAT (de l'anglès pump es turbines) o fins i tot dispositius de recuperació d'energia de tipus domèstic. Per aprofundir en la caracterització d'aquests dispositius es realitzen una sèrie d'assajos d'una micro turbina hidràulica, obtenint tant la corba pressió-cabal com la corba tensió-cabal. La metodologia desenvolupada s'aplica al cas de la Xarxa Matriu de Bogotà. Aquesta xarxa presenta una orografia en el terreny que la fan idònia per a recuperar energia d'excés que arribi als nusos de consum. Per a això s'aplica la metodologia i s'estudien les diferents opcions per instal·lar recuperadors energètics a nivell de xarxa. Per a això, és necessari realitzar una anàlisi de costos per observar la rendibilitat que ofereixen aquestes màquines en funció de l'energia que són capaços d'extreure., [EN] The needs of our society and the great dependence on energy resources, originate the demand for new technologies that allow the saving and energy recovery (ER). Water is one of the greatest natural resources available in nature, on which a large part of the generation of energy depends. Therefore, the energy study of water distribution networks (WDN), allows identifying the losses of these systems and determining the potentially recoverable energy (PER) that could be obtained from the excess energy supplied to users. Some works of the literature have defined the energy balance of the WDN, and have characterized the PER as the difference between the energy supplied to each node of consumption and the minimum energy required. However, in the present work, a new energy balance is proposed, distinguishing three more terms within the term of PER. That is, the amount of energy that can be recovered in the system has its origin in three points: the users, the network conduits in which new RE elements can be installed, and the regulation and control valves that can be replaced by small turbines. This methodology allows obtaining the maximum possible energy that could be recovered from a water distribution system. To demonstrate the validity of the methodology, it is applied to the Balerma irrigation network. Although most of the work focuses on the possible installation of RE elements at the network level, chapter 4 is devoted to studying the different devices that could be installed: different types of conventional hydraulic turbines, PATs (from English pump as turbines) or even domestic type energy recovery devices. To deepen the characterization of these devices, a series of hydraulic miniturbine tests are carried out, obtaining both the pressure-flow curve and the voltage-flow curve. The methodology developed applies to the case of the Red Matriz of Bogotá. This network presents an orography in the terrain that makes it ideal to recover excess energy that reaches the consumption nodes. To do this, the methodology is applied and the different options for installing energy recovery devices at the network level are studied. For this, it is necessary to perform a cost analysis to observe the profitability offered by these machines in terms of the energy they are able to extract.

A mini hydropower Plant is planned to be constructed on an artificial irrigation canal with a maximum flow rate of 40 m3/sec and a water head of 20 m. The canal irrigation schedule lasts for 10 months per year; January and February are usually considered as a period for the maintenance of the hydraulic works. For purpose of comparison, five different designs of HPP and 3 alternatives of installed electric power were proposed and considered in order to choose technically and economically optimal solution. To compare and evaluate alternatives, in this study we take into consideration calculation of total electric energy produced in 2 years. Calculation includes also cost of civil works, cost of mechanical and electrical works, costs of operation and maintenance and cost of investment. As result of this study the best alternative to be installed in mini HPS was chosen.

Studies are conducted on axial hydraulic turbine for very low head application which operates on low speed. Design optimization is generated by optimizing the blade airfoil and blade cascade during development of the turbine blades. Blade airfoil is optimized to obtain optimum value of ratio of Lift coefficient Cl and Drag coefficient Cd, in the range of turbine operation by utilizing of XFOIL that controlled via MATLAB. These airfoils are used to develop the blade cascade. To increase the benefits of fluid flow passing through the turbine blades, the analysis and optimization of the blade cascade is conducted. Vortex panel method is used to analyze the fluid flow inside cascade to gain the maximum of the lift force, in order to optimize the potential power of the fluid that can be utilized by the turbine rotor. The cascade optimization is including arrangement of the incidence angle of the cascade to reduce cascade losses and blade loading by applying the concept of shock-free inflow. Numerical analyses are conducted to determine the performance of the designed turbine with the commercial CFD. The results of numerical simulations show that the turbine can be operated at a maximum efficiency of 91% at various ranges of flow rates.

This work is devoted to the investigation of oscillations in the hydropower plants, consisting of synchronous generator, hydraulic turbine and speed governor. It is motivated by the accident happened on the Sayano-Shushenskaya hydropower plant in 2009 year. A mathematical model of the hydropower unit is based on the equations of Park-Gorev for synchronous generator described in detail in (Adkins, 1962), (Boldea, 2006), on the turbine equations taken from (Pervozvanskii, 1986), and on the simplified equation of governor suggested in (Merkur'ev and Shargin, 2008). For modeling the system parameters of the Sayano-Shushenskaya hydropower plant were used. Oscillations in zones, which were not recommended for operation, were found. The obtained results are consistent with full-scale tests results carried out for hydropower units of the Sayano-Shushenskaya hydropower plant in the late 80s of the XX century and published in (Gluhih, 1988).