磨损间隙和机组转速对发电机推力轴承油槽密封泄露的影响

Influence of Wear Clearance and Unit Speed on Oil Tank Seal Leakage of Thrust Bearing

随着投产时间的推移,水电站轴承油槽盖密封被逐渐磨损,动静配合间隙增大,油雾逸出现象严重。为了探究磨损间隙和机组转速对油槽密封处油雾泄露的影响,建立了发电机推力轴承油槽密封几何模型,应用SSTκ-ω湍流模型,对不同间隙(0.2~2.0 mm)、不同转速(100~500 r/min)下油雾的泄露情况进行稳态数值模拟计算。结果表明,建立泄漏量、间隙值及转速三者之间的函数关系表达式,可发现间隙值对油雾泄漏量的影响比转速高;间隙增加后,密封齿的节流作用减弱,密封进口压力降低,加剧了油槽盖顶部的油雾泄露;进、出口处的流速随间隙值的增加而增大,当间隙值由0.2 mm增加至2.0 mm时,进口速度由20 m/s增加到113 m/s,出口速度由76 m/s增加到144 m/s,泄漏量由0.0344 kg/s增加到0.0538 kg/s。该研究可为水电站轴承油槽密封结构的优化、电站运行策略的制定及密封性能的判断提供一定的理论基础。

As the time goes by,the seal of the bearing oil tank cover of the hydropower station is gradually worn,the gap between dynamic and static increases,and the oil mist escapes seriously.In order to explore the influence of wear clearance and unit speed on oil mist leakage in oil tank seal,a geometric model of thrust bearing oil tank seal of generator was established.Using SSTκ-ωturbulence model,steady state numerical simulation was carried out for oil mist leakage at different clearances(0.2 mm-2 mm)and rotating speeds(100 r/min-500 r/min).It is found that the influence of clearance value on oil mist leakage is much higher than that of rotational speed.With the increase of clearance,the ling thrott-effect of sealing teeth is weakened,the sealing inlet pressure is reduced,and the oil mist leakage at the top of the tank cover is aggravated.The inlet and outlet velocity increases with the increase of wear clearance value.When the ance clear-value increases from 0.2 mm to 2 mm,the inlet velocity increases from 20 m/s to 113 m/s,the outlet speed ses increa-from 76 m/s to 144 m/s,the leakage volume increases from 0.0344 kg/s to 0.0538 kg/s.The research can provide a theoretical basis for the optimization of sealing structure,the formulation of power station operation strategy,and the judgment of sealing performance.