CHEN Huilong, SHI Dichao, HOU Wan, CHENG Qian, CHEN Yingjian, WEI Zepeng, LIU Ruirui
Based on Eulerian multiphase flow model and evaporation condensation model, the vapor-liquid-solid three-phase flow model involving high-temperature vaporization, solid particles, viscosity-temperature effect and Newtonian internal friction effect for high temperature dynamic pressure mechanical seals was established.The effects of groove depth, groove width ratio, helix angle and groove diameter ratio on the vaporization of lubricating film, the distribution of solid particles and the sealing performance were studied.The results show that the volume fraction of solid particles of the lubricating film increases with the increase of groove depth and groove diameter ratio, and reaches the maximum value at a groove width ratio of 0.5.While the variation solid particle volume fraction with the helix angle is related to the rotational speed.The average vapor phase volume fraction of the lubricating film decreases with the increase of groove depth and increases with the increase of helix angle.When the groove width ratio is 0.7, the average vapor phase volume fraction reaches the maximum value, and when the groove diameter ratio is above 0.3, the average vapor phase volume fraction increases with the increase of groove diameter ratio.When the groove depth is 8 μm, there is a sudden change in the vapor phase and solid particle phase of the lubricating film, and the groove depth is less than 8 μm, it is in a state of higher gas phase and smaller solid particle phase, but the opposite is true when the groove depth is higher than 8 μm.The sealing performance analysis based on vapor-liquid solid flow shows that the it is beneficial to the sealing performance when selecting a groove depth of about 9 μm, a groove diameter ratio of about 0.6, a helix angle from 16°to 20°, and a groove width ratio from 0.3 to 0.4.When using a groove depth of over 8 μm and a groove width ratio of less than 0.5, it is beneficial for suppressing vaporization by selecting a smaller groove diameter ratio at higher speeds and a larger groove diameter ratio at lower speeds.
