渗透性气体介质沿机械密封端面逆泄漏方向逃逸行为数值研究

Numerical Analysis on the Escape Behavior of Permeable Gas Media in the Reverse Leak Direction of Mechanical Seals

研究穿透性、挥发性较强的气体介质如氦气、氩气、氟利昂沿机械密封端面逆泄漏通道向阻隔液的扩散问题。针对某型主泵双端面机械密封,以32#透平油作为阻隔液,基于分子动力学计算氩气分子、氟利昂分子在32~#透平油中的平均均方位移,采用线性拟合方法获得氩气分子、氟利昂分子的近似扩散系数,计算接触式机械密封的泄漏量,并与氩气、氟利昂气体反向渗透量进行比较。结果表明,该型机械密封在正常工作过程中,氩气、氟利昂等渗透性较强的气体不存在通过扩散作用沿机械密封逆泄漏方向逃逸至大气的可能。

The diffusion of permeable gas media such as helium,argon and Freon in the reverse leak direction of mechanical seals was studied. Aimed at the dual face mechanical seal of a main pump which used No. 32 turbine oil as barrier media to seal gas media,the mean square displacement（ MSD） of argon and Freon molecular in No. 32 turbine oil was calculated based on molecular dynamics. The approximate diffusion factors of argon and Freon molecular in No. 32 turbine oil were obtained by linear line fitting method. The leakage of the dual face mechanical seal was calculated and was compared with permeation flux of argon and Freon molecular. The results show that,during the normal working process of this type of mechanical seal,there is no possibility that the permeable gas media such as argon and Freon can escape to ambient along the reverse direction of mechanical seal end face.