Water Turbine Classifications

Reaction and Impulse Water Turbines

WATER TURBINE CLASSIFICATION Describing the main categories of water turbines and sorting them according to their principles

By: Eng. Mo`tasem H. Y. Abushanap

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Water Turbine Classifications:

1- Reaction water Turbines 2- Impulse water turbines.

1.1 Reaction water Turbines a- Francis Turbines b- Kaplan Turbines c- Tyson d- Gorlov

1.2 Impulse Water Turbine a- Pelton Wheel b- Turgo c- Water wheel d- Jonval Turbine e- Archimedes Screw


1.1 Reaction Turbines 1.1.1

Francis Turbines

Fig. 1.1.1.1, Side-view cutaway of a Francis turbine

Fig. 1.1.1.2 Francis Inlet Scroll, Grand Coulee Dam

It is an inward-flow reaction turbine that combines radial and axial flow concepts. They operate in a head range of 10 to 650 meters (33 to 2,133 feet) and are primarily used for electrical power production. The power output generally ranges from 10 to 750 megawatts, though mini-hydro installations may be lower. Runner diameters are between 1 and 10 meters (3 and 33 feet). The speed range of the turbine is from 83 to 1000 rpm. Medium size and larger Francis turbines are most often arranged with a vertical shaft. Vertical shaft may also be used for small size turbines, but normally they have horizontal shaft. 1.1.2

Kaplan Turbines

Fig. 1.1.2.1, Vertical Kaplan Turbine (courtesy Voith-Siemens).

Fig. 1.1.2.2, Vertical Kaplan Turbine (courtesy VERBUND-Austrian Hydro Power). a propeller-type water turbine which has adjustable blades. The Kaplan turbine was an evolution of the Francis turbine. Its invention allowed efficient power production in low-head applications that was not possible with Francis turbines. The head ranges from 10-70 meters and the output from 5 to 120 MW. Runner diameters are between 2 and 8 meters. The range of the turbine is


from 79 to 429 rpm. Kaplan turbines are now widely used throughout the world in high-flow, low-head power production. 1.1.3

Tyson a hydropower system that extracts power from the flow of water. This design doesn't need a casement, as it is inserted directly into flowing water. It consists of a propeller mounted below a raft, driving a power system, typically a generator, on top of the raft by belt or gear. The turbine is towed into the middle of a river or stream, where the flow is the fastest, and tied off to shore. It requires no local engineering, and can easily be moved to other locations.

Fig. 1.1.3.1 and Fig 1.1.3.2: Tyson Turbine 1.1.4

Gorlov Is a water turbine evolved from the Darrieus turbine design by altering it to have helical blades/foils. The physical principles of the GHT work are the same as for its main prototype, the Darrieus turbine, and for the family of similar Vertical axis wind turbines which includes also Turbine wind turbine Quiet revolution wind turbine Urban Green Energy. GHT, turbine and quiet revolution solved pulsatory torque issues by using the helical twist of the blades.

Fig. 1.1.4.1 and Fig 1.1.4.2: Gorlov Turbine


1.2 1.2.1

Impulse Turbines Water Wheel is a machine for converting the energy of free-flowing or falling water into useful forms of power. A water wheel consists of a large wooden or metal wheel, with a number of blades or buckets arranged on the outside rim forming the driving surface. Most commonly, the wheel is mounted vertically on a horizontal axle, but the tub or Norse wheel is mounted horizontally on a vertical shaft. Vertical wheels can transmit power either through the axle or via a ring gear and typically drive belts or gears; horizontal wheels usually directly drive their load.

Fig. 1.2.1: Water Wheel 1.2.2

Pelton Wheel

Pelton wheels are the preferred turbine for hydro-power, when the available water source has relatively high hydraulic head at low flow rates. Pelton wheels are made in all sizes. There exist multi-ton Pelton wheels mounted on vertical oil pad bearings in hydroelectric plants. The largest units can be up to 200 megawatts. The smallest Pelton wheels are only a few inches across, and can be used to tap power from mountain streams having flows of a few gallons per minute. Some of these systems utilize household plumbing fixtures for water delivery. These small units are recommended for use with thirty meters or more of head, in order to generate significant power levels. Depending on water flow and design, Pelton wheels operate best with heads from 15 meters to 1,800 meters, although there is no theoretical limit.


Fig. 1.2.2.1 Pelton Wheel

1.2.3

Turgo is an impulse water turbine designed for medium head applications. Operational Turgo Turbines achieve efficiencies of about 87%. In factory and lab tests Turgo Turbines perform with efficiencies of up to 90%. It works with net heads between 15 and 300 m.

Fig. 1.2.3.1 Turgo turbine

1.2.4

Cross flow turbine

Unlike most water turbines, which have axial or radial flows, in a cross-flow turbine the water passes through the turbine transversely, or across the turbine blades. As with a water wheel, the water is admitted at the turbine's edge. After passing the runner, it leaves on the opposite side. Going through the runner twice provides additional efficiency. When the water leaves the runner, it also helps clean the [email protected] [email protected]

runner of small debris and pollution. The cross-flow turbine is a low-speed machine that is well suited for locations with a low head but high flow. Fig. 1.2.4.1 Cross Flow Turbine

1.2.5

Jonval Turbine Water descends through fixed curved guide vanes which direct the flow sideways onto curved vanes on the runner, This type is efficient at full gate, but at partial gate it is less efficient than a Francis turbine. The usual orientation of the wheel was horizontal and the first devices were even alternatively named as "horizontal water wheels". However some sources mention turbines with both vertical and horizontal shafts.

Fig. 1.2.5.1 Jonval Turbine


References Reaction Turbines Francis http://en.wikipedia.org/wiki/Francis_turbine Kaplan http://en.wikipedia.org/wiki/Kaplan_turbine Tyson http://en.wikipedia.org/wiki/Tyson_turbine fig.1.1.3.1 http://permaculturewest.org.au/ipc6/ch08/shannon/index.html fig.1.1.3.2 http://oneplusplus.com/AeroDynamic2/FreeFlowTech.html Gorlov http://en.wikipedia.org/wiki/Gorlov_helical_turbine fig 1.1.4.1 http://www.climateandfuel.com/pages/tidal.htm fig 1.1.4.2 http://www.symscape.com/blog/vertical_axis_wind_turbine

Impulse Turbines Water wheel http://en.wikipedia.org/wiki/Waterwheel Pelton Wheel http://en.wikipedia.org/wiki/Pelton_wheel Turgo http://en.wikipedia.org/wiki/Turgo_turbine cross flow turbine http://en.wikipedia.org/wiki/Banki_turbine Jonval Turbine http://en.wikipedia.org/wiki/Jonval_turbine


extra resources http://www.energybible.com/water_energy/water_turbines.html http://permaculturewest.org.au/ipc6/ch08/shannon/index.html


Water Turbine Classifications

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