Study on the Influence of Rotational Speed and Pad Temperature of Pumped-Storage Set on Oil Mist Leakage of Thrust Bearing

Abstract

The accumulation of oil mist in the thrust bearings poses a threat to the safety of the unit, leading to financial and environmental losses. To investigate the generation and influencing factors of oil mist in the oil tank of the thrust bearing in a pumped-storage power station, a novel numerical simulation method is proposed for calculating the oil–oil mist–air multi-phase flow based on the VOF model, RNG k−ε turbulence model, and Lee model. The proposed numerical method’s reliability is verified using field operation data. The effects of rotational speed and pad temperature on the formation of oil mist inside the oil tank were examined from two perspectives of internal and external oil leaks. The research revealed two accumulation areas where oil mist is generated and accumulated: between the thrust head and the oil-retaining ring and near the oil slinger. The former causes external oil leaks due to pressure differences, while the latter causes internal oil leaks due to the rotor blast effect. An increase in temperature and rotational speed exacerbates the formation of oil mist. Furthermore, an increase in speed decreases the pressure change rate at the wall of the inner tank (external oil leaks) by 5.95% and at the oil slinger (internal leaks) by 44.64%. Consequently, compared to external oil leaks, internal oil leaks are more likely to occur.