Peltontyyppiset

Peltontyyppiset refers to a classification of hydroelectric turbines known as impulse turbines. These turbines operate based on the principle of impulse, where a high-velocity jet of water strikes buckets or vanes on the turbine's runner. The kinetic energy of the water is converted into rotational mechanical energy, which then drives a generator to produce electricity.

The most well-known example of a peltontyyppiset turbine is the Pelton turbine, named after its inventor Lester Allan Pelton. These turbines are characterized by their open-flume design, meaning the water jet is not confined within a casing once it leaves the nozzle. This allows for easy access and maintenance.

Peltontyyppiset turbines are particularly suited for high head, low flow applications. This means they are most efficient when there is a significant vertical drop in the water level (high head) and the volume of water available is relatively small (low flow). The high head allows for the generation of high-velocity water jets, which are essential for the impulse principle to be effective.

The design typically involves one or more nozzles that direct precisely shaped water jets onto a series of spoon-shaped buckets arranged around the circumference of the runner. As the water strikes the buckets, it imparts momentum, causing the runner to spin. The split in each bucket redirects the water flow, minimizing energy loss and maximizing efficiency. The speed of the runner can be controlled by adjusting the flow rate through the nozzles, usually by a spear valve within the nozzle.