螺旋槽干气密封静止状态密封性能研究

螺旋槽干气密封因设备故障检修、停车等处于静止状态时,其密封性能相比旋转状态下具有明显的差异性和关联性。研究螺旋槽干气密封在静止时的密封性能。根据螺旋槽窄槽理论,得到螺旋槽干气密封静止时密封端面间气膜压力控制方程,并运用解析法求解,获得端面间气膜压力分布、开启力和泄漏率等密封性能参数。结果表明:随着边界压力或膜厚增大,静态泄漏率逐渐增大,当静态泄漏率达到JB/T11289-2012标准规定的最大静态泄漏率时,端面仍处于接触状态;静止状态下的开启力、槽根处的气膜压力和泄漏率随槽深的增加先增大,在槽深大于一定值后趋于稳定;密封端面间的开启力、泄漏率总体上随台槽宽比的增加而减小,但在台槽比为0~10范围内,开启力和泄漏率的变化不大。

Research on Sealing Performance of Spiral Groove Dry Gas Seals at Rest

When the dry gas seal of spiral groove is in static state due to equipment troubleshooting or shutdown,its sealing performance has obvious difference and correlation compared with the seal in rotating state.The performance of the spiral groove dry gas seal was studied under static state.Based on the narrow groove theory of spiral grooves,the control equations for the gas film pressure between the sealing end faces of the spiral groove dry gas seal at rest were obtained and solved by an analytical method.The results show that as the boundary pressure or film thickness increases,the static leakage rate at rest is increased gradually,and when the static leakage rate reaches the maximum static leakage rate specified in the JB/T 11289-2012 Standard,the end faces are still in contact states.The opening force,the pressure at the root of the groove and the leakage rate in the static state are increased with the increasing of the groove depth,and then tend to be stable when the depth of the groove is greater than some value.As a whole,the opening force and leakage rate between the sealing end faces decrease with the increasing of the width ratio of the land to groove.However,when the width ratio of the land to groove is in the range from 0 to 10,the influence of the width ratio on the opening force and leakage rate is not obvious.