超高速弹性箔片端面气膜密封自适应运行机理及提稳控漏策略研究

Compliant foil face gas seal (CFFGS) is a new conception seal which has good performance of self-adaptive and leakage control in ultra-high-speed and strong vibration working conditions, and hopefully breaks through the technical bottleneck of rigid surface structure face gas seal which shows poor anti-disturbance and impact resistance ability to become one of the key technology of shaft-end seals of ultra-high-speed rotary machine, but the working mechanism and design method are still unclear. The ultra-high-speed bump-type CFFGS is chosen as the research object and the research method of which theory combine with experiment is adopted in this project. Considering the coupling effect of high-speed gas turbulent effect, blockage effect and inertial effect, meanwhile considering the features of structure, force and deformation of the bump-type CFFGS, the coupling models of full-film gas lubrication with elastic deformation under steady and dynamic state are built. The influence of working conditions and structure parameters on steady and dynamic state behaviors and performances of the seal are studied systematically. In order to reveal the self-adaptive mechanism, the space-time interaction regularity of film thickness, film pressure and elastic deformation, and the deformation coordination mechanism of foil face are researched. And in order to put forward the stability improvement and leakage control strategies of the seal, the matching design of mechanical components and optimization design of foil face structure are carried out aiming at high stability and low leakage. The research of this project is expected to develop the design theory and method of ultra-high-speed CFFGS, and meet the improvement of associated industries and technologies.

弹性箔片端面气膜密封（CFFGS）是超高速、强振动工况下具备良好自适应及控漏性能的新概念密封，有望突破现有刚性表面端面气膜密封高速抗扰动、耐冲击能力不足的技术瓶颈，成为超高速旋转机械轴端密封的关键技术之一，但其运行机理及设计方法尚不明确。本项目以超高速波箔型CFFGS为研究对象，采取理论建模与分析结合实验测试与验证的方法，考虑高速气体湍流、阻塞及惯性效应耦合作用，并根据波箔型CFFGS结构及受力变形特点，构建密封稳/动态全膜气弹耦合润滑模型，研究工况、结构等因素对密封稳/动态气弹耦合行为及性能演变规律的影响，分析端面膜厚-膜压-变形的时空交互过程，探明箔片端面变形协调机制，揭示密封自适应运行机理，以高稳定低泄漏为目标开展密封力学元件相容匹配及箔片端面结构协同优化设计，提出提稳控漏策略。以上研究旨在发展超高速CFFGS设计理论与方法，以满足我国流程工业深化发展及关键领域技术升级的迫切需求。

弹性箔片端面气膜密封（CFFGS）是在超高速、强振动工况下具备良好自适应及控漏性能的新概念密封，有望突破现有刚性表面端面气膜密封高速抗扰动、耐冲击能力不足的技术瓶颈，成为超高速旋转机械轴端密封的关键技术之一。本项目以波箔型CFFGS为具体研究对象，建立了CFFGS结构和性能特征参数统一表征体系，基于气体润滑理论、弹性力学理论、动力学理论等，建立了符合超高速CFFGS特点的稳/动态性能理论分析模型并进行了验证；系统研究了工况、结构等因素对密封稳/瞬态气弹耦合行为及性能、气膜动态特性、密封动态响应特性的影响规律，探究了阻塞效应、惯性效应等高速气体效应对密封性能的影响机制，分析了端面膜厚-膜压-变形的时空交互过程，探明了箔片端面变形协调机制，揭示了密封自适应运行机理；科学提出了密封稳、动态性能评价指标，以提高密封超高速运行稳定性和控漏性为目标，开展了密封箔片端面结构协同优化设计及力学元件相容匹配设计，提出CFFGS提稳控漏策略，为发展超高速CFFGS设计理论与方法提供了有力的参考依据。