核电厂主蒸汽隔离阀疲劳寿命分析及监测技术研究

发布时间：2018-06-20 18:21

本文选题：主蒸汽隔离阀 + 振动疲劳　；参考：《哈尔滨工程大学》2014年硕士论文

【摘要】：主蒸汽隔离阀是压水堆核电站二回路关键设备之一,其主要功能是在主蒸汽管线发生破裂事故时进行主蒸汽隔离,防止事故进一步恶化。国内某核电厂主蒸汽隔离阀在正常运行中出现噪声和振动偏大的现象,而且在之后的大修期间,通过设备解体发现隔离阀闸板和安全阀阀内构件出现不同程度的损伤。主蒸汽隔离阀造成的振动和噪声偏大直接影响到主蒸汽管道、主蒸汽隔离阀以及主蒸汽安全阀的安全使用。因此,对主蒸汽隔离阀疲劳分析及寿命监测系统研究对保证核电厂安全具有十分重要的意义。本文基于ASME核电厂运行与维修规范(ASME OM-S/G 2000 PART3),提出了改进型的振动应力以及振动疲劳寿命评估方法,并对主蒸汽隔离阀管系进行振动应力评估以及振动疲劳寿命评估。分析结果表明,管系结构频率响应分析计算得到的振动交变应力大于规范中的允许值,进一步用频域法对振动疲劳寿命评估结果表明,管系振动疲劳寿命高于设计寿命,有一定的安全裕量。另一方面,本文利用有限元接触法对闸板和导向条进行非线性接触分析,计算得到闸板和导向条的接触压力和滑移量以及危险截面的应力以及应变值。本文提出采用临界面SWT法计算微动裂纹扩展方向以及预测微动疲劳寿命,计算及分析结果表明,微动疲劳裂纹萌生位置为闸板与导向条接触边缘位置。微动疲劳寿命预测结果表明在最大载荷下,对主蒸汽隔离阀运行留有较大安全裕量。基于LabVIEW虚拟仪器软件设计了主蒸汽隔离阀疲劳寿命监测系统,仿真分析表明该系统能够对主蒸汽隔离阀疲劳寿命进行实时和离线监测,并具有采样误差小、信噪比高的特点,可实现为运行人员提供直观准确的寿命状态显示和状态分析功能。本文的工作完善了核电厂主蒸汽隔离阀管系振动评估方法,对阀门闸板微动疲劳寿命预测提供了有效的方法。寿命监测系统能为设备提供更加准确的寿命数据,为核电厂设备的老化管理和延寿提供了数据支撑。
[Abstract]:The main steam isolating valve is one of the key equipments in the secondary circuit of PWR nuclear power station. Its main function is to isolate the main steam when the main steam pipeline ruptures to prevent the accident from getting worse. During the normal operation of the main steam isolating valve in a nuclear power plant in China, the phenomenon of noise and vibration is on the high side, and during the later overhaul, it is found that the isolating valve gate and the internal components of the safety valve are damaged to varying degrees through the disassembly of the equipment. The vibration and noise caused by the main steam isolation valve directly affect the safe use of the main steam pipe, the main steam isolation valve and the main steam safety valve. Therefore, it is very important to study the fatigue analysis and life monitoring system of the main steam isolating valve to ensure the safety of nuclear power plant. Based on the ASME OM-S / G 2000 PART3 code for the operation and maintenance of ASME nuclear power plant, this paper presents an improved method for evaluating vibration stress and vibration fatigue life, and evaluates the vibration stress and vibration fatigue life of the main steam isolation valve system. The analysis results show that the vibration alternating stress obtained by frequency response analysis of pipe system is greater than the allowable value in the code. Further, the frequency domain method is used to evaluate the vibration fatigue life. The results show that the vibration fatigue life of pipe system is higher than the design life. There is a certain safety margin. On the other hand, the finite element contact method is used to analyze the nonlinear contact between the sluice plate and the guide bar, and the contact pressure and slip of the gate and guide bar as well as the stress and strain values of the dangerous section are calculated. In this paper, the critical interface SWT method is used to calculate the direction of fretting crack propagation and to predict fretting fatigue life. The results of calculation and analysis show that the position of fretting fatigue crack initiation is the contact edge position between the gate and the guide strip. The prediction results of fretting fatigue life show that under the maximum load, a large safety margin is left for the operation of the main steam isolation valve. Based on LabVIEW virtual instrument software, the fatigue life monitoring system of main steam isolation valve is designed. The simulation results show that the system can monitor the fatigue life of main steam isolation valve in real time and offline, and has the characteristics of small sampling error and high signal-to-noise ratio. It can provide intuitive and accurate life state display and state analysis for operators. In this paper, the method of vibration evaluation of main steam isolating valve system in nuclear power plant is improved, which provides an effective method for predicting the fretting fatigue life of valve gate. Life monitoring system can provide more accurate life data for the equipment and provide data support for the aging management and life extension of nuclear power plant equipment.
【学位授予单位】：哈尔滨工程大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM623.4

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