松支承约束下U型管束面内流致振动机理研究

Heat transfer tubes of steam generator (SG) are the pressure boundaries of primary loop of pressurized water reactors. They are also the key shields to isolate radioactive matters. Leakage of radioactive reactor coolant caused by flow-induced vibration of heat transfer tubes would greatly reduce the safety and economics of nuclear power plants. SG tube wear incident of San Onofre in the US in 2012 rings the alarm bell for the entire global nuclear industry; urgent demand also arises for fundamental researches target at related mechanisms. Based on previous research experiences on two-phase flow turbulent buffeting and fluidelastic instability studies, the applicant of this project would start the current research by building a time domain nonlinear dynamical model that describes the flow-induced vibration of U-tube bundle under loosely supported conditions. The model incorporates the dynamic responses of tube bundle under turbulence excitation, fluid-elastic force and nonlinear contact from loose supports; it also includes the interaction between fretting wear and flow-induced vibration. Experimental studies of flow-induced vibration characteristics of straight tube under air-water mixture and U-bend tube under two-phase Freon will also be carried out. By combining the enormous data collected from theoretical and experimental studies, data pool that consist key parameters and dynamical responses of tube bundle can be constructed by data-driven approach. This data pool will be utilized for parameter sensitivity and uncertainty quantifications. By means of theoretical, experimental and data mining approaches, this project aims at revealing the underlying mechanisms of flow-induced vibration of U-bend heat transfer tube bundles under loosely supported conditions. The unveiled mechanisms would serve as new analytical guidances for the design of heat transfer tube bundles.

蒸汽发生器传热管是压水堆一回路压力边界，是隔离放射性物质的重要屏障。传热管流致振动引起的放射性反应堆冷却剂的泄露会严重影响核电站安全和经济性。2012年美国San Onofre核电站蒸汽发生器传热管的磨穿事故为核工业敲响了警钟，也为相关方面的机理性研究提出迫切需求。申请人在前期两相流湍流激振和流弹失稳的研究基础上，以松支承下U型管束为对象，建立描述管束流致振动的非线性时域模型，考虑磨损深度对流致振动的反作用，分析管束在湍流激振力、流体弹性力和非线性支承力联合作用下的振动响应。项目还将开展气水两相流中直管束和两相氟利昂中U型管束的流致振动试验，研究管束流致振动行为特性。结合理论和试验研究中积累的海量数据，通过数据驱动，构建关键参数到振动响应数据池，开展参数敏感性和不确定性分析。综合理论模型、试验研究和数据挖掘手段，本项目旨在阐明松支承U型管流致振动机理，为传热管束结构设计提供新的理论依据。

在前期两相流湍流激振和流弹失稳的研究基础上，以松支承下U型管束为对象，建立描述管束流致振动的非线性时域模型，考虑微动磨损与流致振动的相互作用，分析管束在湍流激振力、流体弹性力和非线性支承力联合作用下的振动响应。通过开展各种结构形式的管束流致振动试验，研究管束流致振动行为特性。结合理论和试验研究中积累的数据，构建关键参数到振动响应数据池，通过数据驱动开展参数敏感性和不确定性分析。综合理论模型、试验研究和数据挖掘手段分析了松支承U型管流致振动机理，为传热管束结构设计提供新的理论依据。