Micro Hydro Turbine
Francis turbine is one of the most widely used turbines. It has a compact structure, reliable operation and high efficiency range, usually from 85%-93%, and it can be used at different ranges of water flow. Our Francis turbines are commonly used at hydraulic head range of 5-300 meters. For Francis type turbine, water enters runner radially, and leaves axially. Francis type turbine is divided into vertical type and horizontal type. In general, vertical type is often used in micro water power station.
Customer design option: Cast steel runner blades and stainless steel runner blades for option, micro Francis turbine ranging from 5kw to 200kw based on customer’ s local project condition and requirement. off-grid system with voltage controller and off-grid inverter for option, grid connection with normal water turbine generator grid connection and grid inverter option.
Francis type turbine is suitable for water power station with medium or low water head and flow rate. It consists of water guiding chamber, runner, water distributor and draft tube. Functions and conformations of these parts are introduced as follows.
1) Water guiding chamber: There are metal spiral case and metal tank two types of water guiding chamber are generally used. Its main function is to guarantee water enters water distributor evenly and symmetrically in order to reduce loss of water head. Spiral case is the best choice for turbine behavior. Advantages of metal tank type is simple in conformation and low in cost, but loss of water head is bigger than spiral case. So it is generally used in small turbine.
2) Runner: Runner is key part of turbine. Hydraulic energy is transferred to mechanical energy by runner. Runner of Francis turbine consists of vanes, runner hub and torus. Radial water flow is changed to axial flow by vanes. Quantity of vanes can be 10 to 24 pieces. Usual quantity is 14 to 17 pieces. Vanes, runner hub and torus can be made by inblock cast, or by separate cast and welding.
3) Water distributor: Water distributor has the following function.
Guide water enters runner from best direction. Adjust flow rate of water in runner to fit outside load change. For start or stop of generator set.