海上水合物开采泵输系统旋转动密封性能分析

Performance Analysis of Rotating Dynamic Seal for Pump Transportation System in Offshore Hydrate Production

为了实现海洋天然气水合物特殊工况下的开采,并解决水合物破碎回收和泵输工具管串系统中的高压动密封问题,设计了一套滑环组合式密封结合缝隙节流降压系统。利用有限元软件中的自动收缩配合方式和流体渗透加载法模拟分析了高压流体下橡胶密封的密封性能,同时分析了环境压力、O形圈压缩量、O形圈硬度和滑环结构参数变化对密封性能的影响。分析结果表明:自动收缩法和流体渗透加载法配合使用可以较好地模拟高压流体对密封圈的作用力;针对不同的环境压力,应选择合理的压缩率,才能使接触应力不至于过大,同时又能保证密封性能;橡胶硬度对O形圈的最大Mises应力影响不大,不应盲目追求高硬度的橡胶材料;施加在滑环根部的流体压力会导致滑环根部明显地被抬起,使得润滑油一侧的密封接触宽度减小。研究结果对于海上水合物开采泵输系统的现场应用具有一定的指导作用。

To realize the exploitation of marine natural gas hydrate under special working conditions,and to solve the problems of high-pressure dynamic sealing in hydrate crushing recovery and pumping tool string system,a set of sliding ring combined seal combined with gap throttling and pressure reducing system is designed in this paper.The sealing performance of rubber seal under high pressure fluid was simulated and analyzed by means of automatic shrinkage fit method and fluid infiltration loading method in finite element software.The influence of environmental pressure,O-ring compression,O-ring hardness and slip ring structure parameters on sealing performance was analyzed.The analysis results show that:the combination of automatic shrinkage method and fluid infiltration loading method can better simulate the force of high-pressure fluid on the sealing ring;for different environmental pressures,reasonable compression ratio should be selected to make the contact stress not be too large and the sealing performance can be ensured;the rubber hardness has little influence on the maximum Mises stress of O-ring,and rubber material with high hardness should not be blindly pursued.In addition,the fluid pressure exerted on the root of the slip ring will cause the root of the slip ring to be lifted obviously,and the sealing contact width of the lubricating oil side will be reduced.The research results have a certain guiding role for the field application of offshore hydrate production pumping system.