A steel-plastic composite polyurethane movable guide vane vertical surface sealing device

Abstract

The invention belongs to the technical field of hydropower station unit movable guide vane facade sealing and particularly relates to a steel-plastic composite polyurethane movable guide vane facade sealing device. The sealing device comprises a movable guide vane rectangular groove, a polyurethane sealing plate and stainless steel inner hexagonal bolts. The movable guide vane rectangular groove is formed in the large-end face of a movable guide vane body, and screw holes are formed in the bottom of the movable guide vane rectangular groove; the polyurethane sealing plate is of a rectangular plate-shaped structure provided with a protrusion in the middle, and the two sides of the protrusion are provided with bolt holes corresponding to the screw holes; the polyurethane sealing plate is fixed to the movable guide vane body by the stainless steel inner hexagonal bolts. The outer edge of the polyurethane sealing plate and the outer edge of the movable guide vane body are filled with polyurethane composite resin mortar for smooth transition. The sealing device solves the abrasion problem of the sealing device, the sealing performance of a guide vane is greatly improved, and therefore the unit shunt running phenomenon caused when the water leakage amount of the guide vane is increased during normal shutdown is changed, and the power generation efficiency of a unit is greatly improved.

Description

technical field [0001] The invention belongs to the technical field of vertical surface sealing of movable guide vanes of hydroelectric power station units, in particular to a sealing device for the vertical surface of movable guide vanes of steel-plastic composite polyurethane. Background technique [0002] The original form of the vertical seal of the movable guide vane of a Francis turbine in a large domestic hydropower station is a metal rigid seal. After years of operation, under the long-term erosion of high-speed and high-sand content water flow, the rigid facade sealing surface of the guide vane gradually wears out, and the wear of the sealing surface further aggravates the cavitation at the seal, forming a vicious circle, resulting in the sealing surface of the guide vane. Severe wear and cavitation. On the one hand, abrasion increases the water leakage of the guide vane, prolongs the shutdown time of the unit, and increases the wear of the braking mechanism; on th...

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Problems solved by technology

On the one hand, abrasion increases the water leakage of the guide vane, prolongs the shutdown time of the unit, and increases the wear of the braking mechanism; on the other hand, when the water leakage of the guide vane is large, the unit has creeping phenomenon, which seriously threatens the thrust bearing of the unit, etc. The safety of the equipment also directly affects the power generation efficiency of the unit

[0003] After the seal is eroded, it is generally repaired by surfacing welding technology, but it is difficult to manually grind and repair the shape after surfacing welding, and the surfacing welding point has also become a vulnerable point for metal cavitation. After a minor repair cycle, the surfacing welding surface is eroded Further cavitation will damage the base material of the movable guide vane, seriously affecting the service life of the movable guide vane

[0004] Through the search of existing literature and the actual operation and management of hydropower stations, it is found that there is another non-metallic sealing method, which has been applied in practice. The shape of the sealing strip is mainly triangular solid and hollow. It needs to seal the large head surface on the guide vane facade Open the dovetail groove or trapezoidal groove for installation and fixing. This sealing method has a better sealing effect at the initial stage, but after a period of operation, cavitation is prone to occur at the junction of the sealing strip and the dovetail groove or trapezoidal groove. In addition, the sealing strip is small in size, The material is soft, and it is easy to fall off from the fixing groove, causing the sealing strip to fail

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