axial flow turbine
It is suitable for power stations with low water head. Under the same water head, its specific speed is higher than that of Francis turbine. The blades of axial-flow fixed-blade turbine are fixed on the runner body, and the blade placement angle cannot be changed during operation, and the efficiency curve is steep, so it is suitable for power stations with small load change or the number of units can be adjusted to adapt to the load change.
Axial propeller turbine
It was invented by Austrian engineer Kaplan in 1920, so it is also called Kaplan turbine. Generally, the runner blades are operated by hydraulic relays installed in the runner body, which can rotate according to the change of water head and load, so as to keep the best cooperation between the rotating angle of movable guide vanes and the rotating angle of blades, thus improving the average efficiency. Some of the highest efficiencies of this turbine have exceeded 94%.