| Customization: | Available |
|---|---|
| After-sales Service: | 1 Year |
| Warranty: | 1 Year |
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Output: 500KW
Flow Rate: 0.83m³/s
Water Head: 74.68m
Frequency: 50Hz
Certificate: ISO9001/CE/TUV/SGS
Voltage: 400V
Efficiency: 93%
Generator type: SFW500
Generator: Brushless Excitation
Valve : Ball Valve
Runner Material: Stainless Steel
Volute Material: Carbon Steel
Francis turbine definition is a combination of both impulse and reaction turbine, where the blades rotate using both reaction and impulse force of water flowing through them producing electricity more efficiently. Francis turbine is used for the production of electricity most frequently in medium or large-scale hydropower stations.
These turbines can be used for heads as low as 2 meters and as high as 300 meters. Additionally, these turbines are beneficial as they work equally well when positioned horizontally as they do when they are oriented vertically. The water going through a Francis turbine loses pressure, but stays at more or less the same speed, so it would be considered a reaction turbine.
The description of each Francis turbine's main component diagram is as follows.
Spiral Casing
The spiral casing is the inlet medium of water to the turbine. The water flowing from the reservoir or dam is made to pass through this pipe with high pressure. The blades of the turbines are circularly placed, which means the water striking the turbine's blades should flow in the circular axis for efficient striking. So the spiral casing is used, but due to the circular movement of the water, it loses its pressure.
To maintain the same pressure the diameter of the casing is gradually reduced, thus, uniform momentum or velocity striking the runner blades.
Stay Vanes
Stay and guide vanes guide the water to the runner blades. Stay vanes remain stationary at their position and reduces the swirling of water due to radial flow, as it enters the runner blades, thus, making the turbine more efficient.
Guide Vanes
Guide vanes are not stationary, they change their angle as per the requirement to control the angle of striking of water to turbine blades to increase the efficiency. They also regulate the flow rate of water into the runner blades thus controlling the power output of a turbine according to the load on the turbine.
Runner Blades
Runner blades are the heart of any Francis turbine. These are the centers where the fluid strikes and the tangential force of the impact causes the shaft of the turbine to rotate, producing torque. Close attention to the design of blade angles at inlet and outlet is necessary, as these are major parameters affecting power production.
The runner blades have two parts. The lower half is made in the shape of a small bucket to rotate the turbine by using the impulse action of water. While the upper part of the blades uses the reaction force of water flowing through it. The runner rotates through these two forces.
Draft Tube
The pressure at the exit of the runner of the reaction turbine is generally less than atmospheric pressure. The water at the exit, cannot be directly discharged to the tailrace. A tube or pipe of the gradually increasing area is used for discharging water from the exit of the turbine to the tailrace.
This tube of the increasing area is called Draft Tube. One end of the tube is connected to the outlet of the runner. However, the other end is submerged below the level of water in the tail-race.
Francis Turbine Working Principle With Diagram
Francis turbines are employed regularly in hydroelectric power plants. In these power plants, high-pressure water enters the turbine through the snail-shell casing (the volute). This movement decreases the water pressure as it curls through the tube; however, the water's speed remains unchanged. Following the passing through the volute, the water flows through the guide vanes and is directed towards the runner's blades at optimum angles. Since the water crosses the precisely curved blades of the runner, the water is diverted somewhat sideways. This makes the water lose some part of its "whirl" motion. The water is also deflected in the axial direction to exit a draft tube to the tail race.
The mentioned tube reduces the water's output velocity to gain the maximum amount of energy from the input water. The process of water being diverted through the runner blades results in a force that propels the blades to the opposite side as the water is deflected. That reaction force (as we know from Newton's third law) is what makes power to be carried from the water to the turbine's shaft, continuing rotation. Since the turbine moves due to that reaction force, Francis turbines are identified as reaction turbines. The process of altering the direction of the water flow also decreases the pressure within the turbine itself.
Product Advantages
1.Comprehensive processing capacity. Such as 5M CNC VTL OPERATOR, 130 & 150 CNC floor boring machines, constant temperature annealing furnace, planer milling machine, CNC machining center ect.
2.Designed lifespan is more than 40 years.
3.Forster provide one time free site service,if the customer purchases three units (capacity ≥100kw) within one year, or the total amount is more than 5 units. Site service included equipments inspection, new site checking, installation and maintainance training ect,.
4.OEM accepted.
5.CNC machining , dynamic balance tested and isothermal annealing processed,NDT test.
6.Design and R&D Capabilities,13 senior engineers with experienced in design and research.
7.The technical consultant from Forster worked on the hydro turbine filed for 50 years and awarded the Chinese State Council Special Allowance.
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