非接触式气体润滑密封变形的数值分析

Numerical Analysis of Deformation of a Non-Contacting Gas Lubricated Seal

针对离心泵用非接触式螺旋槽气体润滑密封,通过采用有限元法求解描述密封端面间气体流动的雷诺方程,计算了不同约束、不同结构的静密封环和配对动密封环的力变形、端面泄漏量、开启力及气膜刚度等参数,分析了变形对密封特性的影响.结果表明:密封环的力变形使得端面气膜形状大多呈发散型,约束对其变形大小具有重要影响,选择合适的约束可以减小密封面转角、提高气膜刚度、增强密封工作稳定性;变形对密封的开启力影响不大,但变形导致泄漏量增大,并明显改变气膜刚度.

A finite element analysis was performed on the Reynolds equation for the gas flow between the two faces of a non-contacting dry gas face seal with spiral grooves(S-DGS) applied to a centrifugal pump for emission control. Thus the deformation of the both faces caused by pressure and contact forces of the S-DGS consisting of a stator ring with different constructions and/or constrictions and its effect on the principal parameters such as seal opening force, flow leakage rate, and gas film axial stiffness of the seal were investigated. The stability of the several seals with different constructions and constrictions was examined. It was found that the face mechanical deformation caused a divergent sealing gap whose value was closely dependent on the construction and/or constriction of the stator ring. Moreover, the face deformation had a slight effect on the seal opening force but great effect on the gas film stiffness. Therefore, it was imperative and feasible to decrease and even avoid the face deformation by selecting suitable constrictions, which hence made it possible to increase the stability of the S-DGS.