Invented by : James Bicneno Francis
Invented in year : 1849
A Water Turbine is a rotary engine that takes energy from moving water. Water Turbines were developed in the nineteenth century and were widely used for industrial power prior to electrical grids. Now they are mostly used for electric power generation. They harness a clean and renewable energy source. They are also referred as Hydro Turbines or Hydraulic Turbines. Since all water sources vary, so do Water Turbines. These have been designed to suit different locations.
Mechanics Based - Water Turbines are divided into two groups based on their Mechanics
Reaction Turbines - Reaction Turbines are acted on by water, which changes pressure as it moves through the turbine and gives up its energy. They must be encased to contain the water pressure (or suction), or they must be fully submerged in the water flow. Most Water Turbines in use are Reaction Turbines and are used in low (<30m/98ft) and medium (30-300m/98-984ft) head applications. In reaction turbine pressure drop occurs in both fixed and moving blades.
Impulse Turbines - Impulse turbines change the velocity of a water jet. The jet advances on the turbine's curved blades which change the direction of the flow. The resulting change in momentum (impulse) causes a force on the turbine blades. Since the turbine is spinning, the force acts through a distance (work) and the diverted water flow is left with diminished energy. Prior to hitting the turbine blades, the water's pressure (potential energy) is converted to kinetic energy by a nozzle and focused on the turbine. No pressure change occurs at the turbine blades, and the turbine doesn't require a housing for operation. Impulse turbines are most often used in very high (>300m/984ft) head applications .
Inventor Based - There are three main types of Water Turbines, all named after their inventors
- Pelton Wheels - Type of Impulse turbine
- Francis Turbines - Type of Reaction turbine
- Kaplan or Propeller Type Turbines - Type of Reaction turbines
History of the Invention
The earliest known Water Turbines belong to the Roman Empire. Two helix-turbine mill sites of almost identical design were found at Chemtou and Testour, modern-day Tunisia, dating to the late 3rd or early 4th century AD. The horizontal water wheel with angled blades was installed at the bottom of a water-filled, circular shaft. The water from the mill-race entered tangentially the pit, creating a swirling water column which made the fully submerged wheel act like a true turbine. A Water Turbine which had water wheels with curved blades onto which water flow was directed axially, for use in a watermill, was described in an Arabic text written in the 9th century, during the Arab Agricultural Revolution.
Ján Andrej Segner developed a reactive Water Turbine in the mid 1700s. It had a horizontal axis and was a precursor to modern Water Turbines. It is a very simple machine that is still produced today for use in small hydro sites. Segner worked with Euler on some of the early mathematical theories of turbine design.
In 1820, Jean-Victor Poncelet developed an inward-flow turbine. In 1826 Benoit Fourneyron developed an outward-flow turbine. This was an efficient machine (~80%) that sent water through a runner with blades curved in one dimension. The stationary outlet also had curved guides. In 1828, Frenchman, Claude Burdin, coined the word turbine
In 1844 Uriah A. Boyden developed an outward flow turbine that improved on the performance of the Fourneyron turbine. Its runner shape was similar to that of a Francis turbine.
In 1849, James B. Francis improved the inward flow reaction turbine to over 90% efficiency. He also conducted sophisticated tests and developed engineering methods for Water Turbine design. The Francis turbine, named for him, is the first modern Water Turbine. It is still the most widely used Water Turbine in the world today. The Francis turbine is also called a radial flow turbine, since water flows from the outer circumference towards the centre of runner. Inward flow Water Turbines have a better mechanical arrangement and all modern reaction Water Turbines are of this design. As the water swirls inward, it accelerates, and transfers energy to the runner. Water pressure decreases to atmospheric, or in some cases sub-atmospheric, as the water passes through the turbine blades and loses energy.
Development in the Invention of Water Turbine
Around 1890, the modern fluid bearing was invented, now universally used to support heavy Water Turbine spindles. As of 2002, fluid bearings appear to have a mean time between failures of more than 1300 years.
Around 1913, Viktor Kaplan created the Kaplan turbine, a propeller-type machine. It was an evolution of the Francis turbine but revolutionized the ability to develop low-head hydro sites.
Role of Water Turbine in the Improvement of Human Life
- Water Turbines played an important feature of the Industrial Revolution as it gradually made way for the more powerful and efficient steam turbines of the late 19th century.
- Turbine technology also came to be used in jet propulsion and revolutionized aviation in the second half of the 20th century.
- They are still in used in hydroelectric plants. Natural waterfalls and dams provide falling water to power arrays of Water Turbines which are hooked up with electric generators. The energy is then distributed across vast electrical networks. A significant share of global energy consumption is contributed by this clean and cheap form of power.
