Francis Turbine is the most widely used form of turbine today. This turbine can operate between 40 to 600 meters (130 to 2,000 feet) in head height and is most commonly used in hydroelectric power generation. The generators driven by this form will have output power ranging from several kilowatts to 8 million kilowatts, and smaller hydro generators may have lower power output ranges. Hydraulic kinetic energy-derived pressure steel pipes (input pipes) are designed to be between 3 and 33 feet (0.91 and 10.06 meters) in diameter and range from 75 to 1000 rpm. The rotary gate surrounds the periphery of the turbine's rotating flow path, and controls different power production rates by controlling the flow rate of water through the turbine.
In most cases, Francis-type turbines are equipped with high-length bearings to drive distant generators to generate electricity. Generally, there are horizontal and vertical axes. The purpose is to keep water away from the generator. The installation is more convenient and flexible, and it is more convenient to perform maintenance and repair on the generator or the turbine.
Francis turbines are mainly composed of the following components:
Turbine volute: The outer shell that is wrapped around the water wheel motor wheel is called a "volute" because it looks like a snail shell. It has many openings and regular intervals on the whole to facilitate the influx of working fluid When able to push the blades on the flow channel. These openings convert the working fluid into pressure energy before it is trapped in the blade. This is done to maintain a constant flow rate of the working fluid, despite the fact that many openings have been provided to allow the working fluid to enter the blade, while the volute It will shrink gradually along the circumference along the cross-sectional area.
Guide Vane or stay blade: The main function of the guide or stay blade is to convert the pressure energy of the working fluid into kinetic energy. It also guides the working fluid into the rotor blades at the design angle.
Rotor blades: Rotor blades are the most important component of any type of turbine. Because the fluid will hit the rotor blades when the working fluid flows through the turbine, and it is the center point of the tangential force impact, which makes the blades rotate and drive the shaft rod. Rotate and the generator at the end generates electricity. This is the most important power generation center of the turbine. Here, the operator of the turbine must be very careful with the blade angles of the working fluid inlet and outlet, as these are important factors affecting power production.
Tailpipe: The tailpipe is a conduit connected to the turbine runner. The end of the conduit will be connected to a discharge channel to discharge water from the turbine into the discharge channel. The main function of the tail water pipeline is to reduce the flow rate of the discharged working fluid in order to minimize the loss of kinetic energy at the turbine outlet. This makes it unnecessary for the head of the water turbine to be lowered when setting the tail water pipeline.