What are the water turbine selection principles?

The principle of water turbine selection is to select the water turbine with good performance and small size under the condition of meeting the output requirements of the hydropower station and adapting to the parameters (head and flow) of the hydropower station.

Good energy performance requires high efficiency of water turbine, not only the highest efficiency of water turbine, but also the average efficiency of the turbine when the water head and load change. For this reason, it is necessary to select water turbine with gentle curve change within the range of water head change of the hydropower station. Good cavitation resistance, that is to say, the cavitation coefficient of the selected water turbine should be small, which can ensure the stable and reliable operation of the unit. In order to make the size of the water turbine small, it is necessary to select the turbine with high specific speed as much as possible, which has high specific speed and small runner diameter. Therefore, in the selection and calculation of the turbine, the maximum unit flow recommended in the type spectrum shall be adopted, which is equal to or slightly higher than the optimal unit speed, so as to make full use of the water passing capacity of the turbine and reduce the size of the water turbine. In addition to the above basic principles, the selection of water turbine should also consider that the selected unit is easy to supply, less difficult to transport, and convenient for construction and installation, so as to shorten the construction period of hydropower station as much as possible and strive for early generation.