接触式机械密封界面泄漏机理分析

旋转机械装备的密封性能对生产过程的能耗、效率和环保具有重要影响。基于逾渗理论，探讨了接触式机械密封界面空隙状态随动、静环表面分形参数和接触压力变化的规律。研究建立了密封界面单层网格微通道结构模型，指出了密封界面在接触压力作用下表现的逾渗、逾渗点和非逾渗3种状态。根据液体毛细管力和气体Knudsen数，提出了微通道内流体流动判据，分析了密封界面流体的流动阻力和泄漏流量，阐释了接触式机械密封界面泄漏机理。研究结果为接触机械密封优化设计和泄漏控制提供依据。

Analysis on leakage mechanism for contacting mechanical seal interface

The sealing performance of rotating mechanical equipment has an important impact on the energy consumption, efficiency and environmental protection during the production process. Based on the percolation theory, the variation law of the porosity distribution of the contacting mechanical seal interface with fractal parameters concerning the surface topography of rotary and stationary rings as well as the normal contact pressure was also discussed. A single-layer lattice leakage channel structure model of sealing interface was also established. A single-layer lattice leakage model referring to the channel structure of sealing interface was established, and three different states (percolating state, critical percolating state and non-percolating state) can be acquired under different contact pressure. According to the liquid capillary force and gas Knudsen number, the fluid flow criterion in the micro-channel was proposed, and flow resistance and leakage flow through sealing interface were analyzed, moreover, leakage mechanism of contacting mechanical seal interface was also illustrated. The research results provide a theoretical basis for the optimal design and leakage control of contacting mechanical seals in the next work.