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首页> 外文学位 >Mesure de la puissance d'usure d'un tube de generateur de vapeur de reacteur nucleaire en interaction avec une barre anti-vibration.
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Mesure de la puissance d'usure d'un tube de generateur de vapeur de reacteur nucleaire en interaction avec une barre anti-vibration.

机译：与抗振棒相互作用的核反应堆蒸汽发生器管的磨损功率的测量。

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摘要

Fretting-wear of steam generator tubes is an important issue in the nuclear power industry. The two-phase cross-flow induces vibration of the U-tubes and causing impacts against their supports. Anti-vibration bars (AVB) are designed to support the tubes in their U-bend section and to prevent high vibration amplitudes. The minimum clearances between the tubes and the AVBs are set to allow thermal expansion of the tubes and to prevent fretting wear damage. However, larger clearances are often observed in steam generators. They lead to increased impact forces and friction between the tubes and the AVBs. Fretting-wear often causes premature perforation of the tubes, which can result in complete shutdown of the nuclear reactor and high maintenance costs.;Fretting-wear work-rate is the parameter used to predict the service life of steam generator tubes. Fretting-wear depends on the tube and AVB materials, operating conditions within the steam generator and dynamic interaction between the tubes and the AVBs.;The objective of this project is to study experimentally the vibration behavior of a tube in interaction with an AVB. The vibration response and the fretting-wear work-rate are measured in terms of displacement of the tube and contact force with the AVB using a test rig that reproduces the tube/support configuration as encountered in steam generators. This experimental setup was previously designed as part of another research project, but requires full revision to improve the accuracy of the results.;This project is divided into four steps, which are: a) improvement of the experimental test rig and procedure, b) data acquisition of the tube mid-span displacement and the contact force between the tube and the AVB, c) development of a proper signal processing to compute the fretting-wear work-rate and d) analysis and interpretation of the results.;To simplify the model, a straight tube simply supported at both ends and an AVB located at tube mid-span are used. The experimental set-up is instrumented with force sensors and laser sensors that measure the contact force of the tube against the AVB and the displacement of the tube at mid-span. The tube is excited by electromagnets that simulate two-phase cross-flow induced forces using a random narrow band noise of various amplitudes and frequencies. The clearance or preload between the tube and the AVB is successively set at different values with an accuracy of 1mum. The preload configuration corresponds to the case where the tube is restricted at mid-span by the AVB, causing initial deflection of the tube.;Time signals of the mid-span displacement and of the contact force between the tube and the AVB are obtained as a function of clearance and preload. Time signals are then processed using a Matlab code with the proper signal processing including attenuation of aliasing and noise, and calculation of frequency spectra. The fretting-wear work-rate is finally computed by different approaches.;The vibration response analysis is done by inspecting time signals and spectra of the mid-span displacement and the contact force, for excitation forces around the first and the second mode of the tube. For excitation forces around the first mode when there is clearance between the tube and AVB, contact is a combination of sliding and impacts against the AVB. At high preloads, only sliding occurs because the tube mid-span displacement is restricted by the AVB. For excitation forces around the second mode when there is clearance higher than 10mum, there is no contact between the tube and the AVB. When a preload is applied, the contact force is however greater than for the first mode, although the mode shape has a node at the center of the tube. This study also showed similar curves of the fretting-wear work-rate as a function of clearance and preload for excitation forces around the first and the second mode of the tube. In both cases, the work-rate is low for all clearances and high when there is a preload between the tube and the AVB.;In this project, the effectiveness of an AVB on the vibration response and the fretting-wear work-rate of steam generator tubes were evaluated. Moreover, it was shown that proper signal processing must inevitably be done to accurately compute the fretting-wear work-late. Despite the many improvements of the setup and the experimental procedure, many variables such as contact lubrication, surrounding temperature and pressure, and span length, remain to be analyzed. Some recommendations are given to advance research in this field.
机译：蒸汽发生器管的微动磨损是核电工业中的重要问题。两相错流会引起U型管的振动并对其支撑产生冲击。防振杆（AVB）旨在在U形管段中支撑管子并防止高振幅。试管与AVB之间的最小间隙设置为允许试管热膨胀并防止微动磨损。但是，在蒸汽发生器中经常观察到较大的间隙。它们导致增加的冲击力和管与AVB之间的摩擦。微动磨损通常会导致管子过早穿孔，从而导致核反应堆完全停机并增加维护成本。微动磨损工作率是用于预测蒸汽发生器管的使用寿命的参数。微动磨损取决于管子和AVB的材料，蒸汽发生器内的工作条件以及管子和AVB之间的动态相互作用。;该项目的目的是通过实验研究与AVB相互作用的管子的振动行为。振动响应和微动磨损工作率是根据试管的位移和与AVB的接触力测量的，使用的测试装置可以再现在蒸汽发生器中遇到的试管/支撑结构。该实验装置以前曾被设计为另一个研究项目的一部分，但需要进行全面修订以提高结果的准确性。该项目分为四个步骤，分别是：a）改进实验测试装置和程序，b）管中跨位移和管与AVB之间的接触力的数据采集，c）开发适当的信号处理以计算微动磨损工作率，以及d）分析和解释结果。在该模型中，使用了仅在两端支撑的直管和位于管中跨的AVB。实验装置配备了力传感器和激光传感器，可以测量管子对AVB的接触力以及管子在中跨时的位移。该管由电磁体激发，该电磁体使用各种振幅和频率的随机窄带噪声模拟两相错流感应力。管与AVB之间的间隙或预紧力以1mum的精度连续设置为不同的值。预加载配置对应于AVB将管限制在中跨的情况下，从而引起管的初始偏转;获得中跨位移和管与AVB之间的接触力的时间信号为间隙和预紧力的函数。然后使用Matlab代码对时间信号进行适当的信号处理，包括混叠和噪声的衰减以及频谱的计算。最终通过不同的方法来计算微动磨损的工作速率。振动响应分析是通过检查时间跨度和中跨位移和接触力的频谱以及第一和第二模式的激励力来完成的。管。当管和AVB之间有间隙时，对于围绕第一模式的激振力，接触是滑动和冲击AVB的组合。在高预紧力下，由于管的中跨位移受AVB限制，因此仅会发生滑动。当间隙大于10μm时，对于第二模式周围的激励力，管和AVB之间没有接触。然而，当施加预载荷时，接触力比第一模式大，尽管模式形状在管子的中心有一个节点。这项研究还显示了微动磨损率的相似曲线，它是管的第一和第二模式周围的激振力与间隙和预载的函数。在这两种情况下，所有间隙的工作率都很低，而在管和AVB之间存在预载时，工作率很高;在本项目中，AVB对振动响应和微动磨损工作率的有效性对蒸汽发生器管进行了评估。此外，结果表明，不可避免地必须进行正确的信号处理才能准确计算微动磨损工作时间。尽管在设置和实验程序方面进行了许多改进，但仍有许多变量（例如接触润滑，周围温度和压力以及跨度）需要分析。提出了一些建议，以推进该领域的研究。

著录项

  • 作者

    Lalonde, Valerie.;

  • 作者单位

    Ecole Polytechnique, Montreal (Canada).;

  • 授予单位 Ecole Polytechnique, Montreal (Canada).;
  • 学科 Engineering Mechanical.
  • 学位 M.Sc.A.
  • 年度 2012
  • 页码 181 p.
  • 总页数 181
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类
  • 关键词

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