上游泵送机械密封液膜流场近似解析计算  

Approximate analytical calculation of liquid film flow field on upstream pumping mechanical seal

作　　者：张伟政[1] 于踪洋 丁雪兴[1] 

机构地区：[1]兰州理工大学石油化工学院,兰州730050

出　　处：《应用力学学报》2015年第4期694-698,712,共5页Chinese Journal of Applied Mechanics

基　　金：国家自然科学基金(50965010;51165020)

摘　　要：对螺旋槽上游泵送机械密封的工作原理进行了描述,基于N-S方程和连续性方程推导出了二元流动的雷诺方程。用近似解析计算的方法得出了一定边界条件下螺旋槽上游泵送机械密封端面内液体的压力分布、流速分布、泄漏量变化等液膜特性的表达式。通过Maple软件对该数学模型进行了计算,计算结果显示螺旋槽上游泵送机械密封端面液膜内的压力分布呈三维凸形曲面,这表明该密封结构具有明显的流体动压效应。通过对泄漏量的解析计算,可以得到该密封结构稳定性较好,并在理论上能实现零泄漏的结论。这表明,采用本文方法得到的计算结果与已有文献较为吻合,充分说明了其可靠性;同时这一方法应用于上游泵送机械密封尚属首次,为以后的相关研究提出了新的思路。与此同时,通过与有限元方法所得到的计算结果对比可以发现:有限元方法所得到的压力分布结果出现了明显的尖点和突变,与已有文献存在一定的差距;而本文的近似解析法得到的压力分布曲线则较为平滑,与已有文献相符。The working principle of spiral groove upstream pumping mechanical seal is described, and the binary flow Reynolds equation is deduced based on the N-S equations and the continuity equations. Expressions of spiral groove upstream pumping mechanical seal of the liquid related to the pressure distribution, velocity distribution and variation characteristics of leakage of liquid film are obtained by approximate analytical calculation method under certain boundary conditions. The mathematical model is calculated by Maple software. Calculation results show that the spiral groove upstream pumping mechanical seal face liquid film pressure distribution is a three-dimensional convex surface, which indicate the sealing structure possesses a significant fluid dynamic pressure effect. Based on the calculation of the leakage, the seal structure can be obtained better stability and realize zero leakage in the theoretical conclusion. A large number of experiments and simulations are conducted, and the results agree well, which shows the reliability of the developed calculation method. The developed method applied to the upstream pumping mechanical seal for the first time, it would offer a new alterative for the future research. At the same time, comparison between the calculated results and the finite element method results reveal that pressure distribution obtained by the finite element method possess sharp points and mutations, which have much difference with the experimental ones, while the pressure distribution curve by the developed approximate analytical method is relatively smooth, match the experimental results very well.

关 键 词：螺旋槽 上游泵送机械密封 近似解析法 压力分布 

分 类 号：TQ051[化学工程]