The Francis turbine is a type of water turbine that was developed by James B. Francis. A water turbine is a rotary Engine that takes energy from moving water James Bicheno Francis ( May 18 1815 &ndash September 18 1892) was a British - American Engineer. It is an inward flow reaction turbine that combines radial and axial flow concepts. A water turbine is a rotary Engine that takes energy from moving water
Francis turbines are the most common water turbine in use today. They operate in a head range of ten meters to several hundred meters and are primarily used for electrical power production. Hydraulic head is a specific measurement of water pressure or Total energy per Unit weight above a Geodetic datum.
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Development
Water wheels have been used historically to power mills of all types, but they are inefficient. Grand Coulee Dam is a Hydroelectric Gravity dam on the Columbia River in the U A water wheel is a means of extracting power from the flow (or fall of water otherwise known as Hydropower. 19th century efficiency improvements of water turbines allowed them to compete with steam engines (wherever water was available). A water turbine is a rotary Engine that takes energy from moving water A steam engine is a Heat engine that performs Mechanical work using Steam as its Working fluid.
In 1826 Benoit Fourneyron developed a high efficiency (80%) outward flow water turbine. For the game see 1826 (board game. Year 1826 ( MDCCCXXVI) was a Common year starting on Sunday (link will display Benoît Fourneyron ( October 31, 1802 &ndash July 31, 1867) was a French Engineer, born in Saint-Étienne. Water was directed tangentially through the turbine runner causing it to spin. Jean-Victor Poncelet designed an inward-flow turbine in about 1820 that used the same principles. Jean-Victor Poncelet ( July 1, 1788 &ndash December 22, 1867) was a French Engineer and Mathematician who served Year 1820 ( MDCCCXX) was a Leap year starting on Saturday (link will display the full calendar of the Gregorian calendar (or a Leap year S. B. Howd obtained a U. S. patent in 1838 for a similar design. Year 1838 ( MDCCCXXXVIII) was a Common year starting on Monday (link will display the full calendar of the Gregorian Calendar (or a Common
In 1848 James B. Francis improved on these designs to create a turbine with 90% efficiency. Year 1848 ( MDCCCXLVIII) was a Leap year starting on Saturday (link will display the full calendar of the Gregorian Calendar (or a Leap James Bicheno Francis ( May 18 1815 &ndash September 18 1892) was a British - American Engineer. He applied scientific principles and testing methods to produce the most efficient turbine design ever. More importantly, his mathematical and graphical calculation methods improved the state of the art of turbine design and engineering. His analytical methods allowed confident design of high efficiency turbines to exactly match a site's flow conditions.
Theory of operation
The Francis turbine is a reaction turbine, which means that the working fluid changes pressure as it moves through the turbine, giving up its energy. Zh-yue三峽大壩 The Three Gorges Dam ( is a hydroelectric River Dam that spans the Yangtze River in Sandouping, The Francis turbine is a type of Water turbine that was developed by James B A casement is needed to contain the water flow. The turbine is located between the high pressure water source and the low pressure water exit, usually at the base of a dam. A dam is a barrier that divides waters. Dams generally serve the primary purpose of retaining water while other structures such as Floodgates, Levees
The inlet is spiral shaped. Guide vanes direct the water tangentially to the runner. This radial flow acts on the runner vanes, causing the runner to spin. The guide vanes (or wicket gate) may be adjustable to allow efficient turbine operation for a range of water flow conditions.
As the water moves through the runner its spinning radius decreases, further acting on the runner. Imagine swinging a ball on a string around in a circle. If the string is pulled short, the ball spins faster. This property, in addition to the water's pressure, helps inward flow turbines harness water energy.
 Francis Turbine and generator |
 Guide vanes at minimum flow setting (cut-away view) |
 Guide vanes at full flow setting (cut-away view) |
At the exit, water acts on cup shaped runner features, leaving with no swirl and very little kinetic or potential energy. The kinetic energy of an object is the extra Energy which it possesses due to its motion Potential energy can be thought of as Energy stored within a physical system The turbine's exit tube is shaped to help decelerate the water flow and recover the pressure.
Application
Large Francis turbines are individually designed for each site to operate at the highest possible efficiency, typically over 90%.
Francis type units cover a wide head range, from 20 meters to 700 meters and their output varies from a few kilowatt to 1000 megawatt.
In addition to electrical production, they may also be used for pumped storage; where a reservoir is filled by the turbine (acting as a pump) during low power demand, and then reversed and used to generate power during peak demand. Hydro-storage redirects here For storage of water for other purposes see Reservoir.
Francis turbines may be designed for a wide range of heads and flows. This, along with their high efficiency, has made them the most widely used turbine in the world.
See also
External links
Hydroelectricity is electricity generated by Hydropower, ie the production of power through use of the gravitational force of falling water Hydropower, hydraulic power or water power is power that is derived from the Force or Energy of moving water which may A turbine is a rotary Engine that extracts Energy from a Fluid flow A water turbine is a rotary Engine that takes energy from moving water The Kaplan turbine is a propeller-type Water turbine that has adjustable blades The Pelton wheel is among the most efficient types of Water turbines.Dapyx Software network: MP3 Explorer | Ebook Manager | Zenithic