基于流固热耦合的油气两相动压密封追随动态特性

为提升油气两相动压密封的运转稳定性和抗干扰能力,研究其密封补偿环的响应运动,揭示油气两相动压密封的追随动态特性, 考虑温度、变形对密封环和流体膜的综合作用,采用MATLAB软件建立密封环与流体膜的流固热耦合有限元分析模型. 计算流体膜的动态刚度和阻尼系数,求解油气两相动压密封的受迫振动模型,分析补偿环的响应运动. 讨论转速、压差、油气比、弹簧刚度和O形圈阻尼对密封补偿环响应运动角向振幅和轴向振幅的影响,分析密封的追随动态特性. 结果表明:提高转速和油气比有利于提高密封的追随动态特性；压差、弹簧刚度和O形圈阻尼的增大不利于密封补偿环的追随响应运动,其中弹簧刚度和O形圈阻尼增大前期,补偿环响应振幅变化不敏感,增大后期,补偿环响应振幅急剧降低. 研究结果为油气两相动压密封的补偿机构优化和动态性能研究提供理论支撑,并得到基于流固热耦合的油气两相动压密封追随动态特性求解方法.

Follows dynamic characteristics of oil-gas two-phase hydrodynamic seals based on fluid-solid-thermal coupling

To improve the operation stability and anti-interference ability of oil-gas two-phase hydrodynamic seal, the response motion of its sealing compensation ring was studied, and the following dynamic characteristics of oil-gas two-phase hydrodynamic seal were revealed. Considered the comprehensive effect of temperature and deformation on sealing ring and fluid film, a finite element analysis model of fluid-solid-thermal coupling between sealing ring and fluid film was established by using MATLAB software. The dynamic stiffness and damping coefficients of the fluid film were calculated, the forced vibration model of the oil-gas two-phase dynamic pressure seal was solved, and the response motion of the compensating ring was analyzed. The effects of rotational speed, differential pressure, oil-gas ratio, spring stiffness and O-ring damping on the angular and axial amplitudes of motion response of the seal compensation ring were discussed, and the following dynamic characteristics of the seal are analyzed. The results show that the following dynamic characteristics of the seal can be improved by increasing the rotational speed and the oil-gas ratio. The increase of pressure difference, spring stiffness and O-ring damping is not conducive to the follow-up response motion of the compensating ring, in which the response amplitude of the compensating ring is insensitive to the change of spring stiffness and O-ring damping in the early period of increase, and the response amplitude of the compensating ring decreases sharply in the later period of increase. The research results provide theoretical support for the optimization of compensation mechanism and dynamic performance research of oil-gas two-phase hydrodynamic seals, and a method of solving the following dynamic characteristics of oil-gas two-phase hydrodynamic seals based on fluid-solid-thermal coupling is obtained.