reactieturbines

Reactieturbines are a type of hydraulic turbine where the water, as it passes through the turbine, causes both a change in pressure and a change in velocity, resulting in the generation of torque. This is in contrast to impulse turbines, where the water's momentum is the sole driver of the turbine's rotation. The term "reaction" refers to the force exerted by the water on the runner due to the pressure difference and the change in momentum.

The design of reactieturbines involves a casing that encloses the runner, and the water is directed through guide vanes before impinging on the runner blades. As the water flows through the runner, its pressure decreases, and this pressure drop, along with the change in the water's direction and velocity, creates a reaction force that spins the runner. This force is transmitted to a shaft, which in turn drives a generator to produce electricity.

Two primary types of reactieturbines are the Francis turbine and the Kaplan turbine. Francis turbines are versatile and operate efficiently over a wide range of head and flow conditions. They are characterized by a spiral casing, stay vanes, guide vanes, and a runner with curved blades. Kaplan turbines, on the other hand, are propeller-type turbines with adjustable blades, making them highly efficient at low head and high flow conditions, such as those found in riverine hydroelectric plants. The efficiency of reactieturbines is generally very high, often exceeding 90%, contributing to their widespread use in hydroelectric power generation.