航空学报 > 2025, Vol. 46 Issue (10): 431297-431297   doi: 10.7527/S1000-6893.2024.31297

基于引气封油的轴承腔石墨密封系统滑油泄漏流动特性试验

韩量宇1,2, 赵欢1,2(), 常城3, 王平3, 孙丹1,2, 任国哲1,2   

  1. 1.沈阳航空航天大学 航空发动机学院 辽宁省航空推进系统先进测试技术重点试验室,沈阳 110136
    2.沈阳市透平机械先进密封技术重点试验室,沈阳 110136
    3.中国航发四川燃气涡轮研究院,成都 610599
  • 收稿日期:2024-09-28 修回日期:2024-10-23 接受日期:2024-11-25 出版日期:2024-12-06 发布日期:2024-12-05
  • 通讯作者: 赵欢 E-mail:phd_zhaohuan@163.com
  • 基金资助:
    国家自然科学基金(52375195);辽宁省属本科高校基本科研业务费专项资金(LJ222410143090)

Experiment on leakage flow characteristics of lubricating oil for a carbon seal system of bearing chamber based on air-bleeding oil-sealing mode

Liangyu HAN1,2, Huan ZHAO1,2(), Cheng CHANG3, Ping WANG3, Dan SUN1,2, Guozhe REN1,2   

  1. 1.Liaoning Key Lab of Advanced Test Technology for Aerospace Propulsion System,School of Aero-engine,Shenyang Aerospace University,Shenyang  110136,China
    2.Key Laboratory of Turbomachinery Advanced Seal Technology,Shenyang  110136,China
    3.AECC Sichuan Gas Turbine Establishment,Chengdu  610599,China
  • Received:2024-09-28 Revised:2024-10-23 Accepted:2024-11-25 Online:2024-12-06 Published:2024-12-05
  • Contact: Huan ZHAO E-mail:phd_zhaohuan@163.com
  • Supported by:
    National Natural Science Foundation of China(52375195);Fundamental Research Funds for Universities of Liaoning Province(LJ222410143090)

摘要:

压气机引气不足和轴承腔供油压力突增导致的轴承腔滑油泄漏对航空发动机运行稳定性具有重要影响。模拟实际航空发动机基于引气封油方式的轴承腔石墨密封系统结构和工作环境,设计搭建石墨密封系统滑油泄漏流动特性试验装置,可视化观测滑油泄漏流动演变过程,试验研究转子转速和滑油温度对石墨密封系统临界封油压差的影响规律,揭示滑油通过轴承腔石墨密封系统的泄漏流动机理。研究表明:随着封严压差逐渐减小,滑油最先从石墨密封整环的底部泄漏,依次经历渗漏回流、渗漏加剧、滴漏和成股外流4个过程。将滑油形成油滴流出挡板外沿时对应的封严压差作为轴承腔石墨密封系统的临界封油压差。转子转速由4 000 r/min增加至12 500 r/min,临界封油压差减小85.9%,低转子转速使滑油受到的离心力较小,导致滑油成坨状充满密封间隙。滑油温度由40 ℃增加到121 ℃,临界封油压差减小83.1%,低滑油温度增大了滑油的密度和动力粘度,滑油所受的重力和黏滞力较大,导致滑油在密封间隙内发生堆积。

关键词: 轴承腔, 石墨密封, 引气封油, 泄漏流动, 临界封油压差

Abstract:

Leakage of lubricating oil from carbon seal system of bearing chamber caused by insufficient seal pressure from compressor and excessive oil supply pressure of bearing chamber has an important effect on the operational stability of aero-engine. Based on air-bleeding oil-sealing mode, an experimental device was designed and built to simulate structure and working environment of the carbon seal system in bearing chamber of an actual aero-engine. Evolution process of oil leakage flow was visually observed. Effects of rotor speed and oil temperature on the critical oil-sealing pressure difference were experimentally studied. Leakage flow mechanism of oil through the carbon seal system in bearing chamber was revealed. Results show that as the sealing pressure difference gradually decreases, the lubricating oil initially from leaked the bottom of carbon seal ring, undergoing four processes: infiltration and backflow, increased infiltration, droplet-like leakage, and fluid-like leakage. The value of sealing pressure difference corresponding to that the droplet-like leakage occurred was considered as critical oil-sealing pressure difference of carbon seal system in bearing chamber. As rotor speed increased from 4 000 r/min to 12 500 r/min, the critical oil-sealing pressure difference decreased by 85.9%. At lower rotor speeds, the centrifugal force acting on the lubricating oil is relatively small, causing the oil to accumulate in clumps and fill the sealing gap. When the lubricating oil temperature increases from 40 ℃ to 121 ℃, the critical oil-sealing pressure difference decreased by 83.1%. At lower oil temperature, the density and dynamic viscosity of the oil increased, gravity and viscous acting on the oil increased, accumulation of the oil in seal clearance also increased.

Key words: bearing chamber, carbon seal, air-bleeding oil-sealing, leakage flow, critical oil-sealing pressure difference

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