|
|
|
| Study on restraining effect of bearing structure on oil mist escaping of hydro generator unit |
| PANG Jiayang, LIU Xiaobing*, Zeng Yongzhong, Yu Zhishun, Song Han |
| Key Laboratory of Fluid and Power Machinery, Ministry of Education, Xihua University, Chengdu, Sichuan 610039, China |
|
|
|
|
Abstract To perform a deep investigation into the oil mist escaping from the bearing during the operation of the hydrogenerator,without changing the working principle of the oil system, the overall structure of the bearing and the number of bearing bushings, the improved structure of lower guide bearing was designed by adding 4-stage labyrinth seal structure to the oil retaining ring and 4 evenly distributed vent pressure holes with diameter of 8 mm to the top of shaft collar. The VOF two-phase flow model and the SST k-ω turbulence model are the important bases for the numerical simulation of the flow characteristics of the oil-gas mixture in the lower guide bearing structure.According to the analysis of the results, it is found that under the same operation conditions, the oil mist escape amount of the improved structure is reduced by 78.21%, the stability of the flow field in the oil tank is improved, and the number and volume of bubbles in the lubricating oil are reduced. At the same time, it is shown that the pressure difference between the oil tank and the atmoshphere and the sealing performance of the open channel between the oil tank and the outside are the important influencing parameters of the oil mist escaping from the bearing of the hydroturbine generator.The research results can provide gui-dance for hydropower stations to suppress the phenomenon of bearing oil mist escaping.
|
|
Received: 18 March 2021
|
|
|
|
|
|
|
