高速深冷介质动压密封液膜汽化相变性能分析

Performance Analysis of Vaporization Phase Change of Liquid Film of High Speed Cryogenic Medium Dynamic Pressure Sealing

动压密封端面间液膜发生汽化相变,直接改变了端面间的流体润滑方式,对密封的稳定性产生重要影响。建立了液膜汽化相变数值计算模型,研究了不同工况和结构参数对液膜汽化相变程度和区域的影响,分析了液膜汽化相变后密封性能的变化规律。结果表明:工况和结构参数对液膜的汽化相变有着不同程度的影响,随着转速、压力和槽深的增加,液膜的汽化相变被抑制。当转速高于3×10^4 r/min、压力高于0.6 MPa、螺旋角大于20°、槽深大于7μm时,液膜会发生逆汽化现象。液膜的汽化相变对密封性能产生直接的影响。合理选择密封结构参数,可有效利用和控制相变,提高密封性能。

The vaporization phase change of the liquid film between the dynamic pressure seal end faces directly changes the fluid lubrication mode between the end faces,which has an important influence on the stability of the seal.The numerical calculation model of liquid film phase change was established,the area and effects of different working conditions and structural parameters on the vaporization phase change and the area of the vaporization phase change were studied,and the changes of dynamic pressure sealing performance after liquid vaporization phase change were analyzed.The results show that the working condition parameters and structural parameters have different effects on vaporization phase change of liquid film,which is suppressed as the rotation speed,pressure and groove depth increase.When the rotational speed is higher than 3×10^4 r/min,the pressure is higher than 0.6 MPa,the helix angle is greater than 20°,and the groove depth is greater than 7μm,the liquid film will undergo reverse vaporization.The vaporization phase change of the liquid film has a direct effect on the sealing performance.Reasonable selection of sealing structure parameters can effectively utilize and control phase change phenomena and improve sealing performance.