Water Turbine selection principles

The principle that the water turbine chooses to follow is to select a water turbine with good performance and small size under the conditions that meet the output requirements of the hydropower station and are compatible with the parameters of the hydropower station (head and flow).

The so-called good performance includes good energy performance and good cavitation resistance. Good energy performance requires high efficiency of the water turbine. Not only the highest efficiency of the water turbine is high, but also the average efficiency is high when the head and load change. To this end, the water turbine with a gentle curve change should be selected as far as possible within the range of the head change of the hydropower station. The cavitation resistance is good, which means that the selected cavitation coefficient of the water turbine should be small, which can ensure the stable and reliable operation of the unit.

To make the size of the water turbine small, the turbine with a higher specific speed should be selected as much as possible. The water turbine with a higher specific speed has a higher rotating speed and a smaller runner diameter. For this reason, when selecting and calculating the water turbine, the unit speed should be equal to or slightly higher than the optimal unit speed, and the value should be the maximum unit flow recommended in the model spectrum table to fully utilize the water turbine's capacity and reduce the size of the water turbine .