基于计算流体动力学(CFD)的动压效应理论,建立了螺旋槽干气密封气膜流场控制微分方程并进行建模,确定了计算区域.根据文献给出的实验数据,采用FLUENT对气膜压力场进行求解,得到了密封计算区域动环端面处气膜压力沿半径方向的分布.本文对干气密封的稳态特性、槽型几何参数对密封性能(泄漏量和气膜刚度)的影响进行分析研究,并结合文献实验数据对螺旋槽干气密封端面槽型参数进行优化,以保证最低泄漏量的同时得到最大气膜刚度,从而为进一步的研究奠定基础.

A finite element method was proposed to analyze the state performance of the spiral groove dry gas seal,the pressure distribution over the entire seal interface was obtained.Ammonia compressor mechanical seal was transformed in Sichuan Chemical Company by using the structure of bidirectional tandem dry gas seal,the test and practice application shows that spiral groove dry gas sealing property is reliable,which ensures durable operation of the unit and good economic effect was obtained.

The paper discusses technology of spiral groove dry gas seal and analyzes its structure, characteristics and working principle in detail. The seal parameters are also presented and dry gas seal system is analyzed in example.

A finite element method was proposed to analyze the state performance of the spiral groove dry gas seals.The method is based on the fundamental equation of compressible gases.And a discrete equation is inferred.As a result,the pressure distribution over the entire seal interface is obtained.By comparing the computed results with experiment results,it is found that the computed result is reasonable.The results obtaiened is of benefit to the further research of the spiral groove dry gas seal.