Page 55 - 摩擦学学报2025年第5期

第 5 期 胡琼, 等: 复杂工况下槽底超滑移设计对液膜密封性能的影响 689

liquid film seal is disturbed, and its stability is extremely prone to deterioration, which seriously affects its sealing
performance. Therefore, in order to find effective methods to suppress disturbances, this study used numerical methods
to comparatively investigate the effects of the boundary pressure fluctuations, as well as the effects of media
temperature, pressure and rotational speed with considering the viscosity-temperature effect, on liquid film cavitation,
load-bearing capacity, leakage characteristics, and end face temperature under groove bottom super-slip design and
traditional no-slip conditions. The research results showed that under fluctuating media pressure, there was no phase
difference between the fluctuation curves of liquid film cavitation volume fraction, opening force, and leakage rate over
time and the pressure fluctuation curve under the super-slip condition. That was, after the disturbance stopped, the liquid
film seal could immediately resume stable operation. However, under the no-slip condition, there was a significant lag
phenomenon in the fluctuation curves of the above three performance parameters compared to the pressure fluctuation
curve. When considering the viscosity-temperature effect, on the one hand, for both slip conditions, the time for the
opening force and leakage rate to reach stability was independent of the initial media temperature, initial media pressure
and rotational speed. However, the time for the cavitation volume fraction to reach stability decreased with increasing
initial media temperature, while the average temperature in the end face groove area increased accordingly. Additionally,
the cavitation volume fraction and the average temperature in the groove area were also independent of the initial media
pressure and rotational speed. On the other hand, compared to the no-slip condition, the groove bottom super-slip design
could significantly reduce the time for the cavitation volume fraction, opening force, leakage rate and average
temperature in the groove area to reach stability. It could also significantly increase the opening force, reduce the
cavitation volume fraction, and lower the average temperature in the groove area (and could significantly reduce the
leakage rate at high rotational speeds). At the same time, the leakage rate was far less than the standard allowable value.
Lower initial media temperatures or higher rotational speeds could further enhance the improvement in sealing
performance, while the initial media pressure had minimal impact. This study demonstrated that the groove bottom
super-slip design could effectively enable the liquid film seal to cope with the adverse effects of complex environmental
disturbances on sealing performance. The results provided valuable insights for the design and optimization of liquid
film seals in extreme working conditions, and contributed to improve the reliability and durability of sealing systems in
various industrial applications.
Key words: liquid film seal; pressure fluctuation; viscous-thermal effect; super-slip design; sealing performance

液膜密封被广泛应用于能源、航空航天、船舶、 槽和波锥坝槽的降漏减振功效进行了比较，最终证实
石油、化工和冶金等领域，虽然密封副间的液膜有效 所提出的新结构在多类扰变工况下具有出色的密封
[8]
降低了端面的摩擦磨损，但在复杂工况下常发生泄漏 性能与稳定性 . 针对泵用机械密封因介质压力波动
量增大和稳定性降低等问题，严重制约了液膜密封应 造成的“失稳”问题，张金亚等 研究了边界压力波动对
[5]
用领域的拓宽 . 介质压力波动和温度变化是旋转机 液膜空化及密封性能演变规律的影响，结果显示，气
[1]
械常见工况，如油气混输泵中的介质存在难以避免的 相体积分数与压力波动曲线之间均存在相位差，且密
[2]
压力波动 ，火箭发动机涡轮泵高速、高压和高振动 封性能参数随内侧压力波动存在显著的滞后现象，可
等引发的剧烈温升 ，核反应冷却液泵的机械密封必 见，降低压力波动对密封性能的影响是1个重要课题.
[3]
[4]
须能够同时承受高压和高温 等. 当密封腔内发生压 密封面的温度是影响密封性能的关键因素，其值
[5]
力波动时，液膜特性随之变化，密封稳定性降低 ，温 很大程度上取决于密封环与周围密封流体间的传热.
度变化将影响介质黏度和液膜相态，并会使密封环发 有研究显示，八字槽上游泵送机械密封在工作状态下
[6]
生热变形，导致密封效果降低或密封件损坏 . 产生的温升和变形会削弱上游泵送能力，甚至可能造
有关介质压力波动对液膜密封的影响研究较少， 成密封介质的泄漏 ，而通过改变密封端面螺旋槽的
[6]
[7]
[9]
徐鲁帅等 分析了工况连续变化及压力扰动对密封瞬 结构参数可以达到调节液膜温度的效果 ；液膜气化
态特性的影响，认为压力瞬时变化易引发静环轴向速 会导致密封失稳，但同时可以显著降低密封界面的温
[11]
[12]
[10]
度振荡，压差越大，振荡幅值越大；空化率与泄漏量在 度 ；在密封端面非槽区 或外圆周 加工大量微凹
压力突升和压力突降下恢复稳定的能力不同. 随后， 坑也可以降低端面温度. 另有学者认为热变形可以抵
提出了1种螺旋槽和波锥槽组合密封，并将其与螺旋 消部分压力变形，介质温度升高能够使液膜收敛程度