超超临界汽轮发电机组轴系密封系统失稳模式及非线性动力学演变规律的研究

It is about generator rotor-bearing-sealing system of ultra-super critical steam turbine as research object. Rotor dynamics,nonlinear dynamics,vibration fluid mechanics,hydrodynamic lubrication theory and multi-disciplinary theories and methods are used to consider the shaft-sealing system's coupling relationship and seal type. It also analyzes labyrinth seal cavity flow, velocity and pressure field distribution affect law under different labyrinth seal structural parameters. The steam flow excitation force characterization method, labyrinth seal force model and ultra-super critical steam turbine generator rotor bearing sealing system are established to analyze labyrinth seal shaft dynamics influence law of labyrinth seal structure type and parameter stability. It reveals the nonlinear dynamic evolution law and mechanisms of steam flow excitation according to the experimental test data and theoretical analysis. The control method of nonlinear stability, buckling characteristics, buckling patterns, dynamic response and dynamic response are researched in large-scale and ultra-super critical turbine generator shaft. It reveals the mechanism and suppression measures of shaft producing steam flow excitation, and the shaft seal structure's key design parameters and selection criteria are given in research. It provided a reliable theoretical basis and technical support of China's ultra-super steam critical turbine unit dynamics of turbine-generator and solved the key technical problems of labyrinth seal system dynamics design.

以超超临界汽轮发电机组转子-轴承-密封系统为对象，应用转子动力学、非线性动力学、振荡流体力学和流体动力润滑理论等多学科理论与方法，综合考虑轴系密封结构各参数之间耦合关系和密封结构的类型，分析各种迷宫密封结构参数对密封腔内流场、速度和压力场分布影响规律；建立超超临界汽轮发电机组转子-轴承-密封系统的汽流激振力的表征方法、汽封力模型及轴系非线性动力学模型，分析密封结构型式和参数对轴系稳定性等动力学特性的影响规律；根据实验测试数据和理论分析，揭示汽流激振发生的非线性动力学演变规律及机理；研究多源耦合激励下超超临界汽轮发电机组轴系的非线性稳定性、失稳特征和模式、分岔规律和动力学响应等动态特性；揭示轴系产生汽流激振的非线性动力学演变规律及抑制措施，给出轴系密封结构的关键设计参数的选取准则，突破轴系密封动力学设计的关键技术难题，为我国超超临界汽轮发电机组的动力学设计提供可靠的理论基础和技术支撑。

以超超临界汽轮发电机组转子-轴承-密封系统为对象，应用转子动力学、振荡流体力学、非线性动力学和流体动力润滑理论等多学科理论与方法，综合考虑轴系密封结构各参数之间耦合关系和密封结构的类型，分析了各种迷宫密封结构参数对密封腔内流场、速度和压力场分布影响规律；设计了新型迷宫密封结构，分析了结构参数对密封性能和动特性的影响；提出了迷宫密封非线性密封力的改进模型，分析了密封结构型式、可变几何参数和转子结构形式等对气流激振的影响规律；优化了转子-轴承-密封系统实验装置，分析了结构参数等对轴系动力学响应的影响；建立了轴系非线性动力学模型，分析了密封结构型式和参数对轴系稳定性等动力学特性的影响规律，研究了多源耦合激励下机组轴系的非线性稳定性、失稳特征和模式、分岔规律和动力学响应等动态特性及控制方法；揭示了轴系产生汽流激振的机理，给出了轴系密封结构的关键设计参数的选取准则，为我国超超临界汽轮发电机组的动力学设计提供可靠的理论基础和技术支撑。