Reliability evaluation of a dynamic pressure mechanical seal based on liquid film vaporization phase transition

Abstract As a key basic component for leakage prevention in rotating machinery, research on the reliability of mechanical seals has always been the focus of theoretical and practical investigations. A reliability evaluation method for the dynamic pressure mechanical seal based on liquid film vaporization phase transition is proposed. To investigate the affect of the mass transfer coefficient on the vaporization phase transition, a liquid film vaporization model of the hydrodynamic mechanical seal seal face has been established. The working condition parameters and groove structure parameters are selected based on experimental testing. The evaporation characteristics of liquid film under different parameter combinations are analyzed, and as a result, the function of the vaporization characteristics is obtained. The limit state equation of gas phase volume fraction is obtained by using the maximum gas phase volume fraction when the dynamic pressure mechanical seal state changes from liquid phase miscibility to gas phase miscibility. The structural parameters of the groove are sampled based on the Monte Carlo method, and the reliability is calculated using the sampling results and the limit state equation. Finally, the proposed method is used to numerically analyze the reliability of the slot under specific structural parameters.