Hydro generator is the heart of hydropower station. Water turbine generator unit is the most critical main equipment of hydropower plant. Its safe operation is the fundamental guarantee for hydropower plant to ensure safe, high-quality and economic power generation and supply, which is directly related to the safe and stable operation of power grid. The operation environment of water turbine generator unit is related to the health and service life of generator unit. Here are the measures taken to improve the generator operation environment based on the of Xiaowan Hydropower Station.
Oil rejection treatment of thrust oil tank
The oil rejection of thrust bearing will pollute the hydro generator and its auxiliary equipment. Xiaowan unit has also been plagued by oil rejection due to its high speed. The oil rejection of Xiaowan thrust bearing is caused by three reasons: the oil creeping of the connecting bolt between the thrust head and the rotor center body, the oil creeping of the upper sealing cover of the thrust oil basin, and the dislocation of the “t” seal between the split joint seal of the thrust oil basin and the lower annular seal.
The power plant has processed sealing grooves on the joint surface between the thrust head and the rotor center body, installed 8 oil resistant rubber strips, blocked the pin holes in the rotor center body, replaced the original upper cover plate of the thrust oil basin with a contact oil groove cover plate with a follow-up sealing strip, and applied sealant on the full contact surface of the split joint of the thrust oil basin. At present, the oil throwing phenomenon of the thrust oil groove has been effectively solved.
Dehumidification transformation of generator wind tunnel
Dew condensation in the generator wind tunnel of underground powerhouse in South China is a common and difficult problem to solve, which has a direct impact on the insulation of generator stator, rotor and its auxiliary equipment. Xiaowan shall take measures to ensure the reliable sealing between the generator wind tunnel and the outside, and add condensation coating to all water pipelines in the generator wind tunnel.
The original low-power dehumidifier is transformed into a high-power fully enclosed dehumidifier. After shutdown, the humidity in the generator wind tunnel can be effectively controlled below 60%. There is no condensation in the generator air cooler and water system pipelines in the wind tunnel, which effectively prevents the corrosion of the generator stator core and the moisture of relevant electrical equipment and components, and ensures the normal operation of the generator.
Modification of brake ram
Dust generated by the ram during generator braking is a major pollution source causing stator and rotor pollution. Xiaowan Hydropower Station replaced the original brake ram with non-metallic asbestos free dust-free ram. At present, there is no obvious dust during generator shutdown braking, and the improvement effect is obvious.
These are the measures taken by Xiaowan Hydropower Station to improve and improve the generator operation environment. In the century improvement and improvement operation environment of hydropower station, we should scientifically and reasonably design the improvement scheme according to the specific actual situation, which can not be generalized.
Post time: Oct-08-2021
