Micro propeller turbine

Micro hydroelectric turbine series- Micro Axial flow turbine/ Micro propeller turbine/ Micro kaplan turbine generator

Micro Axial flow turbine/ Micro propeller turbine

Axial flow turbine (Propeller turbine) is water flow from the axial direction into the turbine wheel, and from the axial water flow, so called “axial flow turbine”, this kind of turbine is developed on the basis of Francis turbine, to adapt to the low water head large water flow hydraulic conditions.

The structure of axial flow turbine and Francis turbine is the same, also is composed by the spiral case (water room), turbine runner wheel, guide vane (wicket gates) and draft tube and so on. Which in addition to the turbine runner wheel have bigger difference, other components are the same. The following only introduce the characteristics of the turbine runner wheel.

The turbine runner

In order to adapt to large flow conditions, runner blade of axial flow turbine is not too much (is commonly 3 ~ 8), and it looks like a propeller, small runner blades are mostly fixed, usually called “Propeller turbine”. Blade and horizontal level with a certain Angle, and this is the blade angle of the propeller turbine. Different blade angle is suitable for different water head and flow condition.

Installation Angle is usually between -15 ° ~ 20 °. In manufacturing, blade angle is determined by the hydraulic data provided by the customer. Micro hydropower turbine runner blade and cone is integral casting, this is a simple structure, but poor performance. When water head, flow and load change, the water flow direction into the blade changes, the blade can’t adapt to the new flow condition, it may impact, the phenomenon such as flow, vortex, increasing the head loss, and makes a sharp drop in efficiency. Therefore, the propeller turbine runner is only applicable to low head and stable large flow, little change in the flow and head of micro hydropower stations. Seasonal changes in water head and flow rate of water power station, in order to improve the efficiency and improving working conditions, we often use with adjustable blade runner, this kind of turbine we usually called “Kaplan turbine”.