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[en] The first part of the paper contains the choice of small turbines for run of the river power plants. Then a discussion is given on the optimization of the performance of different types of large turbines. Finally a discussion on the safety and necessary maintenance of turbines is given with special attention to bolt connections.
[en] The availability of a high quality Open Source CFD simulation platform like OpenFOAM offers new R and D opportunities by providing direct access to models and solver implementation details. Efforts have been made by Hydro-Quebec to adapt OpenFOAM to hydroturbines for the development of steady-state capabilities. The paper describes the developments that have been made to implement new turbomachinery related capabilities: Multiple Frame of Reference solver, domain coupling interfaces (GGI, cyclicGGI and mixing plane) and specialized boundary conditions. Practical use of the new turbomachinery capabilities are demonstrated for the analysis of a 195-MW Francis hydroturbine.
[en] The paper contains the short description of the design process of the axial flow turbines for Small Hydro. The crucial elements of the process are: ARDES programme for 1D inverse problem (containing the statistic information of the well performed hydraulic units, applying the lifting aerofoil theory); determination of universal hill diagram and optimization of the runner blades geometry by utilization of the 3D CFD codes. As the result of design process with utilization of both design steps, the generated runner blades geometry (1D inverse problem) and some computational results of 3D CFD solver have been presented. As the conclusion some crucial remarks of the designed process have been brought forward.
[en] The draft tube of a hydraulic turbine is the component where the flow exiting the runner is decelerated, thereby converting the excess of kinetic energy into static pressure. However, in some refurbishment cases, the installation of an upgraded runner with an old draft-tube leads to an undesirable efficiency drop as the discharge is increased above the best efficiency point value. It is found to be related to a corresponding sudden variation in the draft tube pressure recovery coefficient at the same discharge. The model of a recent refurbishment which presents this instability is installed in the CREMHyG test rig. Steady and unsteady measurements of velocity and pressure fields of the complex and highly turbulent swirling flow exiting the runner have been carried out at CREMHyG (Grenoble). They included the three components of the velocity. The flow in the draft tube is rich in secondary flows and possible flow separation due to the elbow as well as to the divergent shape of this geometry. Pressure and velocity field measurements in the draft-tube have been performed. They let us identify some phenomena that may explain the origin of the unusual behavior of the draft tube. Finally, the same model, with a modified draft tube geometry that was designed to reduce the efficiency drop phenomenon has been installed. Velocity measurements were made to validate the benefit of such geometry modification.
[en] Behavioral and physical barriers as well as various collection and diversion systems are presented as methods used to prevent turbine passage of fish at hydroelectric developments. Sound projectors, strobe lights, and mercury lights are indicated as repellents or attractants that may be used in hybrid barriers and that are worthy of further investigation. Physical barriers such as barrier nets, bar racks, and fixed screens have been used successfully over a wide geographic range with various fish species, physical layouts, and hydraulic conditions. Fish pumps and travelling screens (collection systems), angled screens, angled rotary drum screens, the Eicher screen, and louvers (diversion systems) are presented as alternatives that would be viable under specific conditions. 16 refs., 9 figs
[en] There are several governor architectures, but in general, all of them are designed to maintain the controlled variable fluctuations within acceptable range. The Proportional, Integral and Derivative (PID) governor is one of the types used to regulate a hydraulic turbine, in which the deviation of the variable controlled is corrected through earnings proportional, integral and derivative. For a definition of the governor parameters and its stability analysis there are several methods that in general can be classified into a time domain and frequency domain. The frequency domain method, based on the control theory, have ease application, expeditious manner of obtaining the parameters, but the physical phenomena involved are linearized. However the time domain methods are more difficult to be applied, but have the advantage of being able to take into account the non-linearities presents in physical phenomena. Despite the time-domain method offers advantages, it does not provides a structured way to optimize the parameters of the governor, since the parameters are obtained through simulations with adopted values. This paper presents a methodology to obtain the turbine governor appropriate parameters through a hybrid model (simulation and optimization model), based on method of characteristic to the hydraulic simulation (time domain) and Genetic Algorithm (GA) to obtain appropriate values. Examples are presented showing the application of the proposed methodology.
[en] Tests were conducted with juvenile alewife to determine the effects of four experimental protocols upon turbine fish passage mortality estimates. Three protocols determined the effect of cumulative stresses upon fish, while the fourth determined the effect of long range truck transportation prior to release into the penstock or tailrace. The wide range in results were attributed to the presence or absence of additional stress factors associated with the experiments. For instance, fish may survive passage through a turbine, or non-turbine related stresses imposed by the investigator; however, when both are imposed, the cumulative stresses may be lethal. The impact of protocol stress on turbine mortality estimates becomes almost exponential after control mortality exceeds 10%. Valid turbine related mortalities may be determined only after stresses associated with experimental protocol are adequately reduced. This is usually indicated by a control mortality of less than 10%. 14 refs., 5 figs., 6 tabs
[en] The paper describes models of the local network operation of the hydraulic turbine-generator unit. Two different models are proposed. They describe the dynamic behaviour of a system in which the unit is connected to an equivalent system. A nonlinear model of the interconnection to an equivalent power system is considered. An optimal controller for load disturbance rejection in water turbine speed and power control is designed. The frequency and power deviations are examined in the case of a sudden load change. (author)
[en] The Bonneville Dam second powerhouse bypass system for juvenile salmon has one 6.1-m submersible travelling screen in each intake of all eight turbines, for a total of 24 screens. These screens set up a hydraulic cushion that deflects juvenile salmon away from the turbine intakes and into vertical bulkhead slots, from which they exit by their own volition into a collection gallery that travels the length of the powerhouse to a dewatering station and the outlet. A multiple-year evaluation was conducted on the comparative survival of subyearling chinook salmon through various passage modes at the dam. Using this information, operational scenarios could then be formulated to provide additional juvenile protection while meeting power system demands. In the summer, the juvenile salmon that passed through the bypass system had significantly lower survival rates than upper and lower turbine, spillway, and downstream control groups. Predation by northern squawfish (Ptychocheilus oregonensis) was suspected to have been the cause of high mortalities among bypassed fish. No significant differences existed between survival rates of upper and lower turbine groups. 7 refs., 2 figs., 1 tab
[en] This study aims to examine the possibility of Micro hydroelectric power plants by using discharged water from Dongbu Sewage Treatment Plant located in Seogwipo City, Jeju do. The results are as follows; The best location for installing the hydropower plant is at the location of EL(+)2.0, the joint owned surface of the water on the west between discharge flow meter chamber and the surface of the sea water. In calculating the quantity of electric power generation, the amount used is 0.157m3/sec, the average 95day water Flow for the recent 3 years. The effective difference in elevation is 12.41m between discharge flow meter chamber and the location of hydraulic turbine installation. Therefore, the quantity of electric generation is expected to be 14.6kW. The monthly quantity of electric generation is 9.46 MW and the yearly quantity of electric generation is calculated to be 113.53 MW. The type of hydraulic turbine to be applied to the hydro power generation is the hydraulic turbine of low head miniflow. Therefore, it is recommended to choose an all-in-one inline-type hydraulic turbine generator. The recommended capacity is 50kW. The hydropower generation has The system of pollution-free energy production. Because the Jejudo government has promoted the free international city project, the image of Clean Jeju is expected to continuously rise. In addition, sewage disposal plants have been regarded as disgusting facilities. Considering this fact, the hydropower generation is expected to build up the image of friendly natural environment. In a word, this project should be considered to be The project of alternative energy production