A penstock is a sluice or gate or intake structure that controls water flow, or an enclosed pipe that delivers water to hydraulic turbines and sewerage systems.
TURBINE
A turbine is a rotary engine that extracts energy from a fluid flow and converts it into useful work.
PELTON TURBINE
The Pelton turbine is an impulse turbine.It requires tangential water flow on one side of the wheel and must therefore operate when only partly submerged. It is best suited to applications with a high head but a low volume flow rate such as fast flowing shallow water courses though it is used in a wide range of situations with heads from as low as 15 metres up to almost 2000 metres. High pressure heads give rise to very fast water jets impinging in the blades resulting in very high rotational speeds of the turbine.
Pelton wheels are ideal for low power installations with outputs of 10kW or less but they have also been used in installations with power outputs of up to 200 MW. Efficiencies up to 95% are possible.
FRANCIS TURBINE
The Francis turbine is a reaction turbine designed to operate fully submerged. Water flow enters in a radial direction towards the axis and exits in the direction of the axis. Its is suitable for lower heads of water of 500 metres or less and is the most commonly used high power turbines. Large scale turbines used in dams are capable of delivering over 500 MW of power from a head of water of around 100 metres with efficiencies of up to 95%
KAPLAN TURBINE
The propeller turbine, is an example of a reaction turbine. Designed to work fully submerged, it is similar in form to a ship’s propeller and is the most suitable design for low head water sources with a high flow rate such as those in slow running rivers. Designs are optimised for a particular flow rate and efficiencies drop of rapidly if the flow rate falls below the design rating. The Kaplan version has variable pitch vanes to enable it to work efficiently over a range of flow rates.
GENERATOR
Powerhouse Generator Bay
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