螺旋槽上游泵送机械密封密封特性数值计算

Numerical Computations of the Seal Performance of Upstream Pumping Mechanical Seals with Spiral Grooves

建立考虑机械密封端面径向锥度的理论模型。采用有限元法求解修正的雷诺方程,得出螺旋槽上游泵送机械密封端面间液体的压力分布,分析不同黏度下膜厚、端面径向锥度对密封特性参数的影响规律。结果表明,螺旋槽上游泵送机械密封端面间液膜压力呈三维凸形曲面;液膜厚度越大,开启力越小,液膜刚度系数在某点取得峰值;径向锥度越大,径向压力峰值、开启力和摩擦因数越小,泄漏率在某点取得最小值;综合考虑较小密封泄漏量和较小摩擦因数,径向锥度取值范围为-1.5×10-4<β<-0.5×10-4较适宜。

A theory model considering the radial taper of the mechanical seal face was given. The revised steady-state Reynolds equation was solved by means of the finite element method, the pressure distribution of the fluid between the seal faces of the upstream pumping mechanical seals with spiral grooves was got. The influence of the film thickness and radial taper at different fluid viscosities on the seal performance was analyzed. The results indicate that the pressure of the fluid between the seal faces of the upstream pumping mechanical seals with spiral grooves is distributed in a three-dimensional convex surface. When the film thickness is greater, seal opening force is decreased, and the fluid film stiffness gets its peak at some point. When the radial taper is greater, the radial pressure peak, seal opening force, and friction coefficient are decreased, and leakage rate gets it＇ s lowest at some point. Desiring for both low leakage rate and low friction coefficient, the range of radial taper of -1.5×10^-4〈β〈-0.5×10^-4 is appropriate according to the calculation results.