can u please, provide a seminar report on kaplan turbine
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The Kaplan turbine is a propeller type water turbine that has adjustable blades. It was developed in 1913 by Austrian professor Viktor Kaplan, who automatically combined the adjusted propeller blades with automatically adjusted wicket doors to achieve efficiency in a wide range of flow and water level. The Kaplan turbine was an evolution of the Francis turbine. His invention allowed for efficient energy production in low-altitude applications that was not possible with Francis turbines. The head oscillates between 10-70 meters and the output of 5 to 200 MW. The diameters of the runners are between 2 and 11 meters. The turbines rotate at a constant speed, which varies from one installation to another. This speed ranges from 69.2 rpm (Bonneville North Powerhouse, Washington, USA) to 429 rpm. The installation of the Kaplan turbine believed to generate the most energy from its nominal head of 34.65 m is from 2013 the Kaplan turbine at the Tocoma power station (Venezuela) generating 235 MW with each The ten corridors of 4.8 m in diameter.
Theory of operation
The Kaplan turbine is an outflow flow turbine, which means that the working fluid changes the pressure as it moves through the turbine and gives up its energy. Energy is recovered from both the hydrostatic head and the kinetic energy of the flowing water. The design combines characteristics of radial and axial turbines.
The entrance is a roll-shaped tube that wraps around the wicket door of the turbine. The water is directed tangentially through the door and spirals over a helix-shaped corridor, causing it to rotate.
The outlet is a special shape shot tube that helps to decelerate water and recover kinetic energy.
The turbine does not need to be at the lowest point in the water flow while the draft tube remains full of water. However, a higher turbine location increases the suction imparted in the turbine blades by the suction tube. The resulting pressure drop can lead to cavitation.
The variable geometry of the wicket gate and the turbine blades allow efficient operation for a range of flow conditions. Kaplan turbine efficiencies are typically more than 90%, but may be lower in very low head applications.
Current research areas include CFD-driven efficiency improvements and new designs that increase the survival rates of passing fish.
Because the propeller blades are rotated in high pressure hydraulic oil bearings, a critical element of Kaplan's design is to maintain a positive seal to prevent the emission of oil in the channel. Discharging oil into rivers is undesirable due to waste of resources and consequent ecological damage.