基于热流体动力效应的机械密封优化设计

OPTIMUM DESIGN OF MECHANICAL SEAL BASED ON THERMO-HYDRODYNAMIC

机械密封端面间的热流体动力效应受介质物性、密封环尺寸和材料以及工况条件等诸多因素的影响。在液膜摩擦热与端面热变形耦合分析的基础上,研究热流体动力效应的形成机理。在考虑热流体动力效应的前提下,以提高液膜承载力、减小泄漏率为目标,提出一种新的机械密封设计方法。依据该方法,可获得机械密封环传热性能最优时的几何尺寸,并可根据承载力和泄漏率的要求确定改形位置的半径Rg和改形扩散角1β。所设计的机械密封具有较高的承载能力和良好的密封性能。

The thermo-hydredynamic in mechanical seal end faces is influenced by some factors, such as the properties of sealed mediums, the dimensions and materials of the rotating ring and the stationary ring, working conditions and so on. Based on the coupling analysis of the frictional heat of the fluid film and the thermal deformation of the end faces of the sealing rings, the formation mechanics of the thermo-hydrodynamic is studied. In consideration of the thermo-hydredynamic, the design technique of the flat end face mechanical seal is established, taking the increase of the beating force of the fluid film in the end faces and the decrease of the leakage rate as the main design objective. By this method, the primary geometrical parameters of the sealing members that correspond to the optimal heat transfer performance can be determined, and the radius of the reshaping location Rg and the divergent angle of the reshaping area β1, according to which the end faces can be reshaped to meet the beating force and the leakage rate requirements, can also be obtained. The mechanical seal designed using this method possesses relatively large beating force of the fluid film and very small leakage rate.