深海球阀阀座密封性能分析与优化

Analysis and Optimization of the Sealing Performance of Subsea Valve Seat

由于深海工况复杂,深海阀门密封结构在工作状态中遇到不稳定工况时,难以运用传统的凭借经验以及基于经典力学理论的常规设计方法进行研究。从深海工况出发,设计出具有双向密封结构的阀杆和螺栓固定式阀座的深海球阀;应用有限元数值模拟软件,通过选取阀座密封面上三条特征路径代替整个密封表面,研究其在海水外压以及介质内压综合作用复杂工况下的变形规律,分析其密封性能,得出其变形与密封比压的关系。结果表明:不同路径处阀座的变形量与密封比压的关系不同,阀座两端的变形量与密封比压无关,阀座中间部分的变形量与密封比压变化相反;减小阀座径向厚度可增大密封比压,并使密封面上的密封比压分布更加均匀,并且当厚度较小时,密封比压增大速度更快。基于研究结果对阀座的尺寸进行优化,减小了阀座的径向厚度,使阀座的密封比压分布更加均匀且符合阀门的密封评价标准。

Because of the complex conditions of deep sea,the working condition of the sealing structure is very unstable. So,it is difficult to study the sealing performance with traditional design methods based on experience or classical mechan ics theories.Based on the deep sea conditions,a deep sea ball valve with a valve rod of double sealed construction and bol ted fixed ball valve seat was designed.By using the finite element numerical simulation software,and choosing three paths in the surface of valve seat to substitute the whole surface,the deformation regularity of the valve was studied under com plex conditions of the external pressure of water and the internal pressure of medium.The seal performance of valve seat was analyzed and the relationship between deformation and sealing pressure was summarized.It is found that the relationship between seat deformation and sealing pressure is different at different paths.The deformation of the ends of the seat is inde pendent of the sealing pressure,and the deformation of the middle part of the seat is opposite to that of the sealing pres sure.Reducing the radial thickness of the seat can increase the sealing specific pressure and make the distribution of the specific pressure on the sealing surface more uniform,and when the thickness is small,the increase of the sealing specific pressure is faster.Based on the study above,the size of the valve seat was optimized by reducing the radial thickness of the valve seat,which makes the sealing specific pressure distribution of the valve seat more uniform and conforms to the sealing evaluation criteria of the valve.