油气两相柔性丝刷封密封性能优化分析及试验研究

Optimization Analysis and Experimental Research on Sealing Performance of Oil-Gas Two-Phase Flexible Bristle Brush Seal

关键词:  柔性丝刷封  多孔介质  油气两相  密封性能  结构优化

Key words:  Flexible bristle brush seals  Porous medium  Oil-gas two-phase flow  Sealing performance  Structural optimization

摘要:

为解决高速轴承腔复杂工况下的密封问题，设计了一种柔性丝刷封结构，通过数值模拟和试验验证，研究其在油气两相介质下的密封性能，分析工况参数和结构参数对柔性丝刷封密封性能的影响，基于正交试验法优选出能够提升密封性能的结构参数。结果表明：柔性丝刷封主要通过轴向段刷丝实现降压节流的目的，靠径向段刷丝实现封油，得到了其封严油气两相介质的密封机理。泄漏率随压差升高而升高，随温度、转速升高而降低，高温高压高转速工况下，柔性丝刷封封油能力下降。适当增加刷丝束厚度、过盈量，减小刷丝直径、前板和背板间隙均能对密封性能起到积极作用，得到了结构参数的较优取值范围，确定了结构参数对柔性丝刷封密封性能影响程度的主次顺序和最优结构组合。

Abstract:

To solve the sealing problem of the high-speed bearing cavity under complex conditions， a flexible bristle brush seal was designed， and its sealing performance under oil and gas two-phase media was studied through numerical simulation and experimental verification， and the effects of working conditions and structural parameters on the sealing performance of the flexible bristle brush seals were analyzed. Based on the orthogonal test method， the structural parameters that can improve the sealing performance were optimized. The results show that the flexible bristle brush seals achieved the purpose of depressurization and throttling through the axial section of the brush bristle and realized the oil sealing by the radial section of the brush bristle， and the sealing mechanism for sealing the oil and gas two-phase medium is obtaining. The leakage rate increases with the increase of pressure difference and decreases with the increase of temperature and rotation speed. Under high temperature， high pressure and high rotational speed conditions， the ability of the flexible bristle brush seals to seal the oil decreases. Appropriately increasing the thickness and interference of the bristle pack， reducing bristle diameter， front plate clearance， and back plate clearance could have a positive effect on the sealing performance， obtaining preferred ranges of structural parameters. The sequence of the degree of influence of structural parameters on the sealing performance of the flexible bristle brush seal and the optimal combination of structural parameters are determined.