Kaplan-Axial Turbine

The axial turbine allows a versatile application and is well used in many areas. An axial turbine or Kaplan turbine operates with differences in height from 2 to 30 meters and a water quantity of up to 20m³/s. The performance of an axial turbine is between 50kW und 1MW.

Function of an axial turbine

In this turbine the water flows parallel to the shaft towards the wheel. The water then flows through the diffuser (guide vane) towards the blades of the wheel and transfers the energy. By the so-called draft tube, the water leaves the turbine again. The wheel can be build depending on the given water data, with three to five blades. The reaction turbine is used at low head and high flow rates.

Controllability

Depending on the water level the turbine has either a fix diffuser and variable blades (simple regulation – also called Semi-Kaplan) or variable diffuser and adjustable blades (dual control). The advantage of a dual controlled regulation is that the turbine can balance fluctuation of water as well as variations in altitude differences. With an optimally adapted regulation can be achieved high efficiency.