多场耦合作用下超高压高速干气密封的设计理论与实验研究

A dry gas seal (DGS) and its support system are the key parts of a centrifugal compressor used in large-scale refineries, petrochemical enterprises or chemical enterprises, which are regarded as the “cardiac equipment ". With the development of ultra-high pressure or ultra-high speed centrifugal compressors, DGS would be subjected to face deformation, phase-change in sealing gas film, face vibration, face wear and face thermal crack. Thus, the efficiency and safety of enterprise are seriously affected. The project will focus on the ultra-high pressure or ultra-high speed DGS. Some researches will be conducted to reduce the amount of leakage and to improve the working stability of the machine. Firstly, the failure mechanism and modes of such a DGS during the operations will be studied under multi-field coupling action. Then the correlations among gas film thermodynamics, gas phase-change, and thermal-mechanical stability with seal system coupling characteristic parameters will be studied. Theoretical analyses combined with laboratory test, series of research works will be conducted based on the theories of tribology, thermodynamics, dynamic and fluid machanics. The main research contents of this project are as follows. Firstly, a fluid-solid-thermo-dynamic coupling sealing performance simulation model is set up to analyze and reveal the failure model, machanism and basic law of a DGS. Secondly, energy dissipation and balance of the DGS system and the whole thermodynamic field and deformation of the seal are analyzed, and the synergic relationship between the face groove and seal ring structure is revealed. At last, the geometric parameters of a DGS are optimized, and the control strategy of seal failure is presented. This project is intended to develop the theory and method of DGS designs and set up to meet the urgent needs of independent supporting key basic parts of China’s modern continuous process industries.

干式气体密封(DGS)是石油、石化和化工等行业中“心脏”设备离心压缩机的关键部件，随着压缩机向超高压/高速的发展，DGS易遭受端面大变形、相变或振动失稳、磨损和热裂等现象威胁，严重影响着企业的经济性和安全性。本项目以上述超高压/高速DGS为对象，以减少上述失效、提高机组安定性为目标，开展多场耦合作用下的密封失效机制与机理研究，探究端面气体热动力效应、相变或热力失稳与系统耦合特征参数之间的构效规律。采取理论建模与分析结合实验测试的方法，基于摩擦学、热力学、动力学和流体力学等学科理论开展研究。主要研究内容为：①建立流固热动耦合的密封性能仿真模型，揭示密封的失效模式、机制和基本规律；②分析DGS系统的能量耗散与平衡及整体热力场与变形，揭示端面型槽和密封环结构间的协同关系；③优化密封结构参数，提出密封失效的控制策略。项目旨在发展DGS设计理论与方法，满足我国现代流程工业自主配套关键基础件的迫切需要。

干式气体密封(DGS)是石油、石化和化工等行业中“心脏”设备离心压缩机的关键部件，随着压缩机向超高压/高速的发展，DGS易遭受端面大变形、相变或振动失稳、磨损和热裂等现象威胁，严重影响着企业的经济性和安全性。本项目以上述超高压/高速DGS为对象，以减少上述失效、提高机组安定性为目标，采取理论建模与分析结合实验测试的方法，基于并耦合摩擦学、热力学、动力学和流体力学等多学科理论开展研究。通过多场耦合作用下密封失效机制与机理的研究，揭示了端面气体热动力效应、相变或热力失稳与系统耦合特征参数之间的构效规律；通过分析DGS系统的能量耗散与平衡及整体热力场与变形，揭示了端面型槽和密封环结构间的协同关系；通过优化密封结构参数，提出了密封失效的控制策略。项目成果发展和完善了DGS设计理论与方法，可满足我国现代流程工业自主配套关键基础件的部分需要。