应力松弛下滑环组合密封性能研究  

Study on the Performance of Combination Seals Under Stress Relaxation

作　　者：张毅[1] 钟思鹏 熊思阳 熊子杰 杨强 ZHANG Yi;ZHONG Sipeng;XIONG Siyang;XIONG Zijie;YANG Qiang(School of Mechatronic Engineering,Southwest Petroleum University,Chengdu 610500,China)

机构地区：[1]西南石油大学机电工程学院,成都610500

出　　处：《机械科学与技术》2024年第9期1485-1492,共8页Mechanical Science and Technology for Aerospace Engineering

基　　金：四川省自然科学基金项目(2022NSFSC0276)。

摘　　要：结合钻井过程中的高温高压工况和橡胶材料的应力松弛特性,利用有限元分析中压力渗透加载方式对旋转组合密封进行双侧加压,分析了流体压力、井下温度对组合密封主密封面的影响。结合有限元分析结果,提取橡胶密封的变形矩阵,并基于热弹流理论建立了旋转形式的滑环组合密封的数值分析模型。数值求解获得了应力松弛下不同的井下温度、粗糙度时的油膜厚度和油膜压力分布,然后通过密封试验分析了泄漏率、摩擦力矩和转速的关系。结果表明:考虑应力松弛后,介质压力越大接触压力越大,此时不易泄漏,不过摩擦力会有所增加;随着温度的升高,接触应力与介质压力几乎相当,此时泄漏量会有所增加,而温升还会引起黏度的降低,使得黏性摩擦力下降;粗糙度增加,导致油膜厚度增大以及膜压减小,进而引起泄漏增幅较快,而摩擦力略有减小;泄漏率和摩擦力随主轴转速增加。Combination with the high-temperature and high-pressure conditions in the drilling process and Stress relaxation(SR)characteristics of rubber,the rotatory combination seal was subjected to bilateral pressure by the loading method of pressure penetration in the finite element analysis,and the influence of drilling fluid pressure,downhole temperature on the main sealing surface of the combination seal was analyzed.Combination with the finite element analysis results,the deformation matrix was extracted,and a numerical analysis model of rotary combined seal based on thermoelastohydrodynamic lubrication(TEHL)theory was established.The oil film thickness and oil film pressure distributions under different downhole temperature,spindle speed when SR was taken into consideration were obtained by numerical method.The results show that after considering stress relaxation,the higher the medium pressure is,the greater the contact pressure will be,hence the tightness is good and it is not easy to leak,and the friction force will increase.As the temperature rises,the contact stress is almost equal to the medium pressure,when the leakage will increase,and the temperature rise will also cause a decrease in viscosity,making the viscous friction decrease.The increase of roughness causes the increase of oil film thickness and the decrease of oil film pressure,leading to the rapid increase of leakage and the slight decrease of friction.Leakage rate and friction force increase with spindle speed.

关 键 词：高温高压 应力松弛 旋转形式的滑环组合密封 摩擦力 热弹流润滑 

分 类 号：TG156[金属学及工艺—热处理]