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 compromises the safety of the unit and prompts financial and environmental losses. To discuss the strategies for limiting its impact, the model uses the VOF approach to calculate the air-oil-oil mist three-phase flow, combined with the Lee model, to solve the evaporation and mass transfer process between the oil and oil mist. Our attention is drawn into the influence of unit speed and pad temperature, on the occurrence of external and internal leaks from the oil tank. A comparison of cases is made with five unit speeds (100 to 500 rpm) at constant temperature (60°C), and with one unit speed (500 rpm) at different temperatures (56°C,60°C,62°C). With constant speed, the rise of pad temperature promotes the evaporation of the lubricating oil in an uneven manner, augmenting the occurrence of oil leaks. From findings, the increase of speed reduces the pressure change rate at the wall of the inner tank (external oil leaks) by 5.95 %, and of the oil slinger (internal leaks), by 44.64%. The present results might help to suggest courses of action to reduce the oil mist leakage.