Hydrogen sealing device and sealing method of steam turbine generator set

Abstract

The invention relates to a hydrogen sealing device and a sealing method for a steam turbine generator set. According to the technical scheme, a generator rotating shaft at the opening of a sealing seat is sleeved with a resistance disc which is fixed together with the generator rotating shaft, and the resistance disc extends into the inner cavity of the sealing seat from the opening of the sealingseat; a first sealing ring and a second sealing ring which slide left and right in the axial direction of the the generator rotating shaft are arranged in the sealing seat on the two sides of the resistance disc correspondingly, a plurality of first spiral grooves which are uniformly distributed are formed in the outer periphery, right opposite to the first sealing ring, of the resistance disc; and a plurality of second spiral grooves which are uniformly distributed are formed in the outer periphery, right opposite to the second sealing ring, of the resistance disc. Compared with the prior art, two-stage spiral groove type dynamic pressure oil film seal between the sealing rings and the resistance disc and two-stage groove type dynamic pressure oil film seal between sealing floating ringsand the generator rotating shaft are required during hydrogen leakage, and the leakage amount is small; and sealing gaps formed between the sealing rings and the resistance disc due to the dynamic pressure effect of the spiral grooves are small, and therefore the leakage can be effectively reduced.

Description

technical field [0001] The invention relates to a sealing method between the dynamic and static parts at both ends of a hydrogen-cooled turbogenerator, which reduces the leakage of hydrogen along the shaft end and the resulting harm to the safe operation of the unit, and is mainly used for hydrogen-cooled generators. seal. Background technique [0002] With the increase of the unit capacity of the generator set, the heat generated during the operation of the generator increases. In order to improve the cooling effect, hydrogen is generally used as the cooling medium in large generator sets to replace water or air. There is a gap between the moving and static parts of the generator, and hydrogen will leak along the gap between the two. Hydrogen is a flammable and explosive gas. When its concentration in the air reaches a certain level, it will cause an explosion, which will cause great harm to the safe operation of the unit and the lives of personnel. Therefore, hydrogen l...

AI Technical Summary

Problems solved by technology

[0004] There are the following problems in the application of circular flow sealing tiles in hydrogen-cooled generator sets: (1) The floating force is not enough

After the hydrogen pressure of the generator increases, the pressure difference between the hydrogen side and the air side becomes larger. After the hydrogen pressure acts on the end face of the sealing ring, an axial thrust will be formed to push the sealing ring to one side, causing tiles to be stuck. (2) After sealing the tile, it will not only cause the temperature of the tile to rise, but also cause unstable vibration; (3) Seal the gap between the pads not too small

If the gap between the sealing tiles is too small, the temperature of the tiles will rise. When the gap between the sealing tiles increases, not only the leakage of hydrogen gas, but also the flow rate of the sealing oil will increase. The sealing oil may flow back into the generator body, resulting in insulation drop and other failures

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