Propeller Turbine Research Articles

Analytical Model of Small Hydropower Plant Working at Variable Speed

In this paper, a small hydropower plant working at variable speeds is analyzed. The energy conversion system contains a propeller turbine, which is coupled directly with a permanent magnet synchronous generator that is connected with a power system through a power electronic converter (PEC). The PEC that consists of a diode bridge rectifier and a DPC-SVM controlled inverter is described using the average value modeling method. The presented analysis considers only the fundamental harmonic component of ac currents and voltages. The system components are structured in the form of equivalent circuits that also include the power losses. The turbine model consists of the discharge and torque characteristics, which are approximated by analytical formulas based on the turbine hill diagram. The dynamic features represent the speed limiter of the guide vane governor and the mass of water, which fills the turbine chamber and the inlet and outlet pipes. The model is verified on a prototype hydropower plant with nominal power of 150 kW by the steady-state characteristic and a transient performance comparison. Such approach is found to minimize the necessary measurement, simplify the description, and provide satisfactory accuracy of the hydroset model.

Identification of the optimal control characteristics of a small hydropower plant using artificial neural networks and the support vector machines method

ABSTRACTThis study investigates a small hydropower plant at varying turbine speeds. The identification of the optimal turbine rotational speed as a function of a flow rate is usually based on the efficiency function of two variables. The existing procedures require a large number of operating points, which prolong the necessary field measurements. In this paper, a new identification procedure based either on the use of a traditional neural network (multi-layer perceptron, radial basis function), or on a support vector machines method using dedicated assessment factors, is proposed. The procedure was tested and verified in an experimental 150 kW small hydropower plant that contained two propeller turbines. The tests highlighted the advantages of the support vector machines network over traditional neural networks owing to the precise approximation under a limited amount of training data. It is shown that even 15 measurement points provide relatively accurate results.

Design of Blade for 5kW Propeller Turbine

Design of Blade for 5kW Propeller Turbine

Twd-10 b/pzl-10s engine emissions evaluation for PZL M28b Bryza airplane

The specificity of measurements of the concentration of harmful exhaust components of turbine engines used for propulsion of aircraft is connected with tests carried out in stationary conditions during engine tests. The conditions of engine load during the test and the concentration of harmful exhaust compounds determined during the measurements may be used to estimate the emissions of these compounds during the flight of the aircraft. A prerequisite is to obtain a correlation of the engine load conditions during a stationary test to the engine load conditions during the flight of the aircraft. This correlation was carried out on the basis of records of the operating parameter values recorded by the on-board aircraft flight recorder. The article presents the results of measurements of concentration of harmful compounds carried out during the pre-start test of the TWD-10B/PZL-10S engine being the source of propulsion of the PZL M28B “Bryza” airplane, implemented on the airport board. The article presents the results of tests and their analysis, allowing us to assess the emission of harmful exhaust gases from turbine propeller engines.

Water vortex hydropower technology: a state-of-the-art review of developmental trends

With the explosive growth of global energy demand coupled with effects of climate change, there is a significant shift towards green energy generation in recent years. Of the various renewable energy resources available, micro-hydro-power and pico-hydro-power remain very popular in both developed and developing countries. Since 2006, significant growth has spurted in the use of artificial free-surface vortices to generate low and ultra-low-head hydropower following the development of the so-called gravitational water vortex hydropower plant. The technology works on the principle of harnessing hydroelectric power from the high angular velocity experienced in the core of a whirlpool generated in a vortex chamber. In this article, a state-of-the-art review is undertaken on the vortex hydropower technology including a historical review of the technology, the underlying hydraulic principles of such devices, overview of research and technologies that have been deployed to date together with an evaluation of their performance and key findings. Currently, there are 19–22 known live vortex hydropower technologies operating internationally with key academic and commercial research activity in Europe and Asia. The average efficiency from these sites was found to be in the region of 53% which is lower than conventional propeller turbines but higher than waterwheel systems. It was found that the vortex plant, due to its ability to sustain relatively high efficiencies at low heads and small to medium flow rates, addresses a gap in the current turbine application chart. Its key advantage lies in the high-power densities produced compared with conventional technologies. The system also demonstrates potential to be able to function as a fish passage; however, stronger validation is required to prove this for a range of turbine systems. Finally, the authors propose a number of areas that should be investigated that should provide immediate improvements to the turbine in terms of performance.

Long-term effect of a tidal, hydroelectric propeller turbine on the populations of three anadromous fish species.

Tidal hydroelectric power has been proposed as one potential solution for sustainable energy sources. The first tidal turbine in North America began continuous operation in the Annapolis River estuary (44 °45'N; 65° 29'W) in June, 1985. The machine is an axial-flow, hydraulic-lift propeller turbine, a type known to cause fish mortality. Anadromous populations of American shad Alosa sapidissima, striped bass Morone saxatilis and Atlantic sturgeon Acipenser oxyrinchus utilize the Annapolis River for spawning and other life history phases. After power generation commenced obvious turbine mortalities of these fishes began appearing downstream of the turbine. Assessments of the A. sapidissima adult spawning runs during 1981-1982 (pre-operation) and 1989-1996 (operational) indicated significant changes in population characteristics after power generation began. Adult length, mass, age and per cent repeat spawners declined and total instantaneous mortality (Z) increased from 0.30 to 0.55. The pre-turbine spawning runs had older fish with numerous adult cohorts whereas by 12 years after operation began runs consisted of younger fish with fewer adult cohorts. During 1972-1987 numerous studies indicated the Annapolis River had an important angling fishery for M. saxatilis, but detailed annual records kept by a fishing contest during 1983-1987 and an elite angler family during the period 1976-2008 demonstrated a rapid decline in the number of fish >4.0 kg after turbine operation began. Pre-turbine catch by the angling family of fish >4.0 kg accounted for 84.1% of total catch, but declined significantly to 39.6% of total catch from 1986-1999, and to none from 2000-2008. The existence of an A. oxyrinchus stock in the Annapolis River was unknown before turbine operation, but during 1985-2017, 21 mortalities were recovered by chance seaward of the turbine. Mechanical strike and cavitation mortalities consisted of juveniles, mature males and gravid and spent females of ages 10 to 53 years found during June to October, the period when this anadromous species returns to its natal river to spawn. The results of the long-term studies at Annapolis indicate managers should realize substantial risks exist for the fish resources of the world's oceans from deployment of instream propeller turbines.

Mixing characteristics in a vessel equipped with cylindrical stirrer

Abstract In this work, the mixing characteristics in a vessel equipped with a cylindrical stirrer were investigated experimentally and numerically in an unbaffled tank. The cylinder stirrer is a cylinder with four openings and four wing panels symmetrically distributed. Mixing characteristics were measured by adding second tracer. The shaft-torque method was applied for the power consumption measurement. Tap water was used as the continuous phase and starch solution was the dispersed phase. CFD investigations on the flow field, power consumption, as well as mixing time, have been performed. Three-dimensional time-dependent flow and mixing prediction have been carried out using Slide Mesh (SM) method embodied CFD package FLUENT 6.3. Mixing time studies were done using a simulated tracer injection experiment. The comparisons of the power numbers and mixing times for a cylinder stirrer, a Rushton turbine and a propeller turbine, have been carried out. It is suggested that the cylinder stirrer is relatively more energy efficient compared with the Rushton turbine and the propeller turbine.

The Positioning Accuracy Based on the UWB Technology for an Object on Circular Trajectory

This paper presents the comparison of filtering methods – median filtration, moving average Kalman filtration and filtration based on a distance difference to determine the most accurate arm length for circular motion, as a model of wind turbine propellers movement. The experiments have been performed with the UWB technology system containing four anchors and a tag attached to 90cm arm that was rotated with speed up to 34.5 rad/s (as a linear speed of 50km/h). The trilateration concept based on the signal latency has been described in order to determinate the position of an object on circular trajectory. The main objective is the circle plane rotation (parallel and perpendicular) with respect to the anchors plane reference system. All research tasks have been performed for various cases of motion schemes in order to get the filtration method for object in motion under best accuracy goal. Filtration methods have been applied on one of two stages of the positioning algorithm: (1) on raw data got from the single anchor-tag (before trilateration); (2) on the position obtained from four anchors and tag (after trilateration). It has been proven that the appropriate filtering allows for higher location accuracy. Moreover, location capabilities with the use of UWB technology – shows prospective use of positioning of objects without access to other positioning forms (ex. GPS) in many aspects of life such as currently developing renewable, green energy sources like wind turbines where the circular motion plays an important role, and precise positioning of propellers is a key element in monitoring the work of the whole wind turbine.

A Hydrodynamic Study of a Propeller Turbine During a Transient Runaway Event Initiated at the Best Efficiency Point

This paper presents a hydrodynamic study of a propeller turbine runaway based on flow simulations and measurements results. Runaways are considered one of the most structurally damaging conditions a hydraulic turbine may encounter. This study focuses specifically on the flow dynamics in the runner and draft tube of a model propeller turbine installed on the test stand of the Hydraulic Machines Laboratory of Laval University, Quebec, Canada. The controlled runaway event reproduced on the test stand was part of a larger study into transient flow conditions. Besides global performance parameters, the measurements also featured 31 pressure transducers mounted on two runner blades. Using those measurements' results, both as boundary conditions and for validation purposes, unsteady Reynolds-averaged Navier-Stokes simulations of the entire turbine were performed. Those simulations featured transient boundary conditions to reproduce discharge and runner speed variations. Using wavelet transforms analysis, the evolution of the dominant pressure fluctuations is tracked in both, the measurements and the simulations. The wavelet analysis revealed the presence of pressure fluctuations with frequencies at a fraction of the runner rotation speed. Numerical results revealed that a vortex structure in the draft tube, similar to a part-load vortex rope, is the cause of those high-pressure fluctuations in the runner. A slight flow separation is observable on the pressure side of the blades but does not alter the flow in the inter-blade channels. Comparisons between experimental and numerical data also outline the limits of the methodology related, among others, with the imposition of strict boundary conditions.

Experimental and Numerical Investigations on the Origins of Rotating Stall in a Propeller Turbine Runner Operating in No-Load Conditions

Hydraulic turbines are more frequently used for power regulation and thus spend more time providing spinning reserve for electrical grids. Spinning reserve requires the turbine to operate at its synchronous rotation speed, ready to be linked to the grid in what is termed the speed-no-load (SNL) condition. The turbine's runner flow in SNL is characterized by low discharge and high swirl leading to low-frequency high amplitude pressure fluctuations potentially leading to blade damage and more maintenance downtime. For low-head hydraulic turbines operating at SNL, the large pressure fluctuations in the runner are sometimes attributed to rotating stall. Using embedded pressure transducer measurements, mounted on runner blades of a model propeller turbine, and numerical flow simulations, this paper provides an insight into the inception mechanism associated with rotating stall in SNL conditions. The results offer evidence that the rotating stall is in fact associated with an unstable vorticity distribution not associated with the runner blades themselves.

Using Regulated Electrical Machines in Small Hydropower Plants Operating in a Power Network

Economic factors of operating hydroturbines used in small hydropower plants, including the Francis turbine, Pelton turbine, and axial Kaplan turbine with fixed blades (propeller turbine), are analyzed and compared as a function of the turbine-rotation frequency. It is found that the regulation of the turbine-rotation frequency depending on the changes in consumption of the energy carrier (water flow) improves the efficiency of the propeller turbines by 8–10% and leads to an increase in power production by the hydroaggregate as a whole. For these turbines, an expression describing the capacity (torque) as a function of the rotation frequency is obtained from the propeller characteristic of the turbine by approximating the frequency dependence of the turbine efficiency by a cubic polynomial. Since relative units were used, the obtained expression describes the characteristics of all propeller-type turbines. A mathematical model of an hydroaggregate consisting of a prototypical axial fixed-blade Kaplan hydroturbine coupled with a frequency-controlled synchronous generator with permanent magnets is developed. The study of static and dynamical operation modes of the above-mentioned hydraulic aggregate on the basis of this mathematical model verified the operability of the system and technical solutions used in its design.

Experimental study on the solid suspension characteristics of coaxial mixers

Coaxial mixers as novel mixers have the characteristics of high flexibility and wide adjustability. Three kinds of coaxial mixers consisting of an outer anchor and different inner impellers (six 45° pitched-blade turbine, propeller and Rushton turbine) and single-impeller mixers were investigated and compared in viscous systems. Effects of rotation and pumping modes, outer impeller speed, inner impeller diameter, liquid viscosity, solid volume fraction and particle diameter on the just-suspension impeller speed and power consumption were also studied. Results showed that the coaxial mixers were more energy efficient than the single-impeller mixers, and had greater advantage in systems of higher viscosity and solid volume fraction. Different from single-impeller mixers, adopting up-pumping mode was more energy efficient for coaxial mixers when the anchor speed was relatively high. In addition, the coaxial mixers with the inner up-pumping propeller and six 45° pitched-blade turbine had obvious superiority compared with the combination of anchor and Rushton turbine in terms of power consumption. Based on the experimental data, a new correlation for predicting just-suspension impeller speed of coaxial mixers was proposed.

Pembuatan dan pengujian turbin propeller dalam pengembangan teknologi pembangkit listrik tenaga air piko hidro (PLTA-PH) dengan variasi debit aliran

Hydroelectric power plants (hydropower) with a power generated capacity of less than 5 kW called "Pico Hydro" (hydropower-PH). Pico Hydro is one of the renewable energy sources that are environmentally friendly. In this study aims to: (1) the manufacture hydropower plants Pico Hydro energy-efficient, renewable and environmentally friendly; (2) determine the efficiency of the turbine with the testing of flow variation; (3) determine the efficiency of generator. Designing and making portable water turbines are easily in the manufacture, operation, and maintenance and has a high efficiency and effectiveness that can use the method of reverse engineering. The production process is performed to create a turbine by the lathe and welding processes. While the materials used are mild steel. Results of this study were found that: (1) the manufacturing process of hydropower plants Pico Hydro can be performed easily by the public; (2) the type of turbine used in hydropower-PH testing is a propeller turbine with 4 blades; (3) flow measurement with V-Notch method showed the following actual debit are 5.38 x10-3 (m3/s), 6.62 x10-3 (m3/s), 7.69 x10-3 (m3/s) and 8.84 x10-3 (m3/s. Turbine efficiency is 3.59 %, 4.26 %, 5.66 % and 7.54 %. The efficiency of the generator has a value of 39.31 %, 40.51 %, 32.55 % and 30.45 %.

Redesign runner turbin pembangkit listrik tenaga pico hydro dengan metode reverse engineering melalui pendekatan teoritis

Daerah tertinggal adalah daerah yang terisolasi secara geografis yang memiliki aksesibilitas sangat rendah. Sebagian besar wilayahnya memiliki tingkat populasi dan kelistrikan yang rendah karena aksesibilitasnya sangat jauh dari jaringan tenaga nasional. Masalah listrik di daerah tertinggal bisa diatasi dengan membangun pembangkit listrik tenaga piko hidro. Salah satu komponen penting piko hidro adalah runner turbin. Berdasarkan proses perancangan teoritis yang mengacu pada laju alir variabel tetap 25 l/s, head 2 m dan jumlah putaran turbin 1500 rpm maka diperoleh runner diameter luar turbin propeller adalah 0,103m, diameter hub 0,515m, jumlah blade adalah 4 dengan profil blade datar, efisiensi hidrolik 76% dan ditargetkan untuk meningkatkan tenaga listrik 490 Watt.

Numerical Predictions of Cavitating Flow around a Marine Propeller and Kaplan Turbine Runner with Calibrated Cavitation Models

Numerical Predictions of Cavitating Flow around a Marine Propeller and Kaplan Turbine Runner with Calibrated Cavitation Models

Simulation of water turbine integrated with electrical generator

The paper presents the analysis of the small hydropower plant working at variable speed. The hydro-set that consists of the guide vanes and propeller turbine integrated with the permanent magnet synchronous generator is simulated by using Computational Fluid Dynamics (CFD) in Ansys Fluent v18.0. The k-ε and k-ω SST models, as well as the one-equation Spalart-Allmaras (SA) model, were tested. The comparison showed the significant divergence of the calculation results. The turbulence model selection influences the average value of the power and also the speed for which the power is maximal.

Influence of Tip Clearance on Small Propeller Turbine Characteristics (Consideration of casing shape)

Influence of Tip Clearance on Small Propeller Turbine Characteristics (Consideration of casing shape)

Flow-driven simulation on variation diameter of counter rotating wind turbines rotor

Wind turbines model in this paper developed from horizontal axis wind turbine propeller with single rotor (HAWT). This research aims to investigating the influence of front rotor diameter variation (D1) with rear rotor (D2) to the angular velocity optimal (ω) and tip speed ratio (TSR) on counter rotating wind turbines (CRWT). The method used transient 3D simulation with computational fluid dynamics (CFD) to perform the aerodynamics characteristic of rotor wind turbines. The counter rotating wind turbines (CRWT) is designed with front rotor diameter of 0.23 m and rear rotor diameter of 0.40 m. In this research, the wind velocity is 4.2 m/s and variation ratio between front rotor and rear rotor (D1/D2) are 0.65; 0.80; 1.20; 1.40; and 1.60 with axial distance (Z/D2) 0.20 m. The result of this research indicated that the variation diameter on front rotor influence the aerodynamics performance of counter rotating wind turbines.

KAJIAN TEORITIK PENGARUH GEOMETRI DAN BENTUK SUDU TERHADAP UNJUK KERJA TURBIN PROPELLER

Abstract Electrical energy is one of the primary needs of Indonesian society that continues to increase. However, until now most of the electricity needs are still supplied by fossil fuel power plants. The fossil energy dependence affects the high cost of distributing electricity to remote areas. The picohydro power plant using propeller turbines is one solution for remote areas. The purpose of this paper is to conduct a theoretical study to obtain optimal propeller blade design with relatively easy design method. Based on the study results obtained geometry and design of turbine propeller that can produce efficiency 73,9% with head water 1,75 m and flowrate 64 l / s. While the propeller turbine design is the diameter of the turbine 200 mm the number of blades 5, and the inlet runner tip 65 °.

Performance Testing of Low Head Small Hydro Power Development in Thailand

This paper presents the development of low head small hydro power in Thailand. Hydropower is one of the renewable resources which spread across all regions in the country. Moreover, it is a source of renewable energy that cheaper than others. The development of local small hydropower design and manufacturing is important to the cost of generating electricity and the stability of domestic energy. The small hydro turbine designed as axial propeller turbine suitable for reservoir with water head range 10 to 20 meters. The runner blade designed as marine propeller shape with reversed mean camber line that obtained a high performance hydro turbine. The turbine has four fixed blades with a diameter of 0.4 meters, 0.35 hub to tip ratio and the 12 pieces of adjustable guide vanes. The turbine shaft directly coupling with a 160 kW induction generator at a rotational speed 1,000 rpm. The performance test results suited for water head all range of 10 to 20 meters with the guide vane angle 40 to 45 degrees and derived with the overall efficiency of 70% to 80%. Total cost of the small hydro turbine generator is USD513/kW.