仿树形槽干气密封稳态性能分析

Steady-state Performance Analysis of Dry Gas Seal with Imitation Tree Groove

针对经典螺旋槽干气密封在反向旋转时动压效果较差,易遭受磨损、失稳等问题,提出一种新型双向旋转式仿树形槽。首先应用SolidWorks软件建立气膜三维模型,然后应用ICEM软件进行网格划分,最后在Fluent软件里对流场进行仿真模拟,将不同膜厚、槽深、转速等参数下开启力、泄漏率的计算结果与螺旋槽进行对比。结果表明:仿树形槽相较螺旋槽可产生明显的动压效应,且开启力较大,但其泄漏率较高,其中仿树形槽膜厚取2μm,槽深取5~7μm时,密封性能较好;膜厚和槽深对密封性能有较大的影响,干气密封开启力随膜厚增大而减小,随槽深的增大而增大;压力和转速增大2种槽型开启力都随之增大,但相比螺旋槽,仿树形槽密封性能受转速影响更小,且具有更好的开启效果。仿树形槽在实现双向旋转的同时也具有较好的密封性能,为双向旋转式干气密封槽型的设计提供一定的参考。

In order to solve the problems of the traditional spiral groove dry gas seal in reverse rotation,such as poor dynamic pressure effect,easy to wear and instability,a new type of bidirectional rotary tree-shaped groove was proposed.SolidWorks software was used to establish the three-dimensional model of gas film,ICEM software was used to divide the grid,and Fluent software was used to simulate the flow field.The opening force and leakage rate of bidirectional rotary tree-shaped groove under different film thickness,groove depth,speed and other parameters were compared with those of the spiral groove.The results show that the tree-like groove can produce obvious dynamic pressure effect and has larger opening force,its leakage rate is higher compared with the spiral groove.When the film thickness is 2μm and the groove depth is 5μm to 7μm,the tree-like groove has better sealing performance.The film thickness and groove depth have a great influence on the sealing performance.The opening force of dry gas seal decreases with the increase of film thickness and increases with the increase of groove depth.The opening force of the two grooves increases with the increase of pressure and speed,but compared with the spiral groove,the sealing performance of the tree-like groove is less affected by the rotation speed and it has a better opening effect.The tree-like groove has good sealing performance while realizing bidirectional rotation,which provides a certain reference for the design of bidirectional rotary dry gas sealing groove.