螺旋槽干式气体端面密封的刚度和泄漏量研究

干式气体端面密封(DGS)是一种非接触式机械密封,适用于大多数气体密封场合,了解密封特性尤其是气膜刚度和泄漏量对正确设计密封非常重要。针对螺旋槽气体端面密封结构,用有限元法计算了密封端面的气膜压力分布及密封的气膜刚度和泄漏量等特性参数,分析了密封面的槽深比、螺旋角和槽长坝长比等两两变化时对密封特性的影响。研究表明,当槽深比取2.0～2.5,螺旋角取15°,槽长、坝长比取1.5～2.0,槽台宽比取1.0,槽数取12～18时,可在确保密封泄漏量低的同时具有较大气膜刚度。

Study of stiffness and leakage rate of spiral groove dry gas face seals

Dry gas face seal (DGS) is one of non-contacting mechanical face seals that can be applied to most of the gas transportation machines. It is very important for designing the seal correctly to understand the seal behavior, especially gas film stiffness and leakage rate. The finite element method was used to solve the two-dimensional Reynolds equation for getting the gas film pressure distribution between the two faces of a spiral-groove face seal (S-DGS). The static sealing performances, such as gas film stiffness and leakage rate were determined. Subsequently the effects of seal geometrical parameters pairwise changed on the behavior of a S-DGS were analyzed, which mainly refer to the ratio of groove depth to gas film thickness, the length ratio of the spiral-groove to the seal dam, and the spiral-groove angle. The recommended geometrical parameters were presented, which can assume large film stiffness while the leakage rate is very small.