W形密封结构金属封隔器性能研究

Research on the Performance of W-shaped Seal Structure Based on Metal Packer

针对橡胶封隔器难以适应150℃、70 MPa以上环境的缺点,设计一种适用于230℃、70 MPa工况,两端传递载荷,中间中空促进径向变形的W形密封结构的金属封隔器,并研究其密封性能。根据工况需求,以温度依赖性和超弹性激发应力选择β-NiTi合金作为W形密封结构材料,以W形结构坐封后产生的接触应力评价其密封性能,以工作承压后W形结构的弹性-超弹性应变率评价其解封性能,分析W形密封结构半径、壁厚及壁厚比对其密封性能的影响,并对设计优化后的W形结构进行密封性能仿真分析。结果表明:结构半径对W形密封结构的密封性能和解封性能影响较小,而壁厚与壁厚比均显著影响密封性能和解封性能;随着壁厚的增加,W形密封结构的密封性能逐渐下降但解封性能逐渐上升,随着壁厚比的增加,密封性能逐渐下降解封性能先上升后下降。对设计优化后的W形结构进行密封性能仿真分析,结果表明,基于β-NiTi合金材料的W形密封结构金属封隔器完全可以适用于高温高压环境,其在230℃、70 MPa的工况下坐封载荷为220 kN,弹性-超弹性应变率达90%以上。

In view of the shortcomings that the rubber packer is difficult to adapt to the working conditions above 150℃and 70 MPa,a metal packer with W-shaped sealing structure was designed,which was suitable for the working conditions of 230℃and 70 MPa,with load transmission at both ends and a hollow in the middle to promote radial deformation,and its sealing performance was studied.According to the requirements of working conditions,β-NiTi alloy was selected as the W-shaped sealing structural material based on the temperature-dependent and superelastic transformation stress,the sealing performance of the W-shaped structure was evaluated by the contact stress generated after setting,and the unsetting performance was evaluated by the elastic-superelastic strain rate of the Wshaped structure under working pressure.The effects of the size radius,wall thickness and wall thickness ratio of the W-shaped sealing structure on its sealing performance were analyzed.The results show that the size radius has little effect on the sealing performance and unsetting performance of the W-shaped sealing structure,while the wall thickness and wall thickness ratio significantly affects the sealing and unsetting performance.With the increase of wall thickness,the sealing performance of the W-shaped sealing structure gradually decreases,but the unsetting performance gradually increases.With the increase of the wall thickness ratio,the sealing performance gradually decreases,and the unsetting performance first increases and then decreases.The sealing performance of the optimized W-shaped structure was simulated and analyzed.It is found that the W-shaped sealing structure metal packer withβ-NiTi alloy material can be fully applied to the high temperature and high pressure environment.Under the working conditions of 230℃and 70 MPa,the load required for the structural setting is 220 kN,and the elastic-superelastic strain rate is more than 90%.