Hydroturbine moving entrance bucket anti-corrosion method

Abstract

The present invention discloses a hydroturbine movable guide blade abrasion-resisting method. It includes the following processes: removing square-head projection from large head end of movable guide blade; making the transition transversal of movable guide blade body and upper end shaft and lower end shaft into inward recessed type; raising roughness of all the portions of said movable guide blade; and NC machining blade type of guide blade and making it be identical to mould line.

Description

[0001] Field [0002] The anti-abrasion method of the water turbine of the present invention is particularly the anti-abrasion method of the movable guide vane of the water turbine. Background technique [0003] For the power station behind the dam, when the river has a high cement and sand content and the reservoir capacity is small, the sediment will fill the reservoir within a few years, and a large amount of sediment will directly pass through the turbine during the flood season, causing serious wear and tear on the flow-passing parts of the turbine, including the top cover, movable parts, etc. Guide vanes and bottom rings, etc., due to the serious abrasion damage of these parts, when the movable guide vanes are closed, the gap between the end face and the vertical surface increases, and the local wear of the end face gap of the movable guide vanes increases by about ten times from the design value, causing the unit to stop for standby. A large amount of water leaks, and t...

AI Technical Summary

Problems solved by technology

Because these high-speed water flows are mixed with a large amount of sediment and the area of ​​the crevice flow suddenly shrinks and expands, so that strong vortices and vacuum bubbles are formed at the diffusion of the crevices, and the vacuum bubbles are instantly collapsed, forming on the guide vane body. High temperature and high pressure cause the movable guide vane to produce vacuum cavitation and sediment wear; at the closed position of the movable guide vane, the high-speed water flow continuously scours the end face of the movable guide vane, the top cover, the bottom ring and the elevation of the movable guide vane for a long time As the usage time increases, the gap of the movable guide vane will become larger and larger, the water leakage of the unit will further increase, and the damage will be more severe. During operation, the movable guide vane is at different openings. The water flow forms a water pressure difference between the front and back of the movable guide vane. Under the action of this pressure difference, the gap water flow is formed on the end surface of the movable guide vane, and a vortex is generated to cause cavitation and sand wear, causing the top cover, bottom ring and the end surface of the movable guide vane to suffer destroy

[0004] And the brake cannot be withdrawn when the unit is shut down for standby, otherwise the unit will automatically turn up. Due to the serious water leakage of the movable guide vane, the power station will waste a lot of precious water resources and endanger the safety of the equipment when it is shut down for standby