流致振动主导机理及减振措施的定量分析  

Quantitative Analysis of Fluid-induced Vibration Mechanism and Measures of Vibration Damping

作　　者：熊哲文 杨军[2] 龚迎莉[1] 唐卉[2] 杨海瑞[1] 张缦[1] XIONG Zhe-wen;YANG Jun;GONG Ying-li;TANG Hui;YANG Hai-rui;ZHANG Man(Department of Eenergy and Power Engineering,Tsinghua University,Beijing 100084,China;Harbin Boiler Company Limited,Harbin 150046,China)

机构地区：[1]清华大学能源与动力工程系,北京100084 [2]哈尔滨锅炉厂有限责任公司,哈尔滨150046

出　　处：《电力学报》2021年第5期411-420,共10页Journal of Electric Power

基　　金：国家重点研发计划(2019YFE0102100)。

摘　　要：近年来大型蒸汽轮机和锅炉在国内外火力发电厂得到了广泛的应用,随之的工程应对的方式是增大换热器的体积、增大平均管跨的距离,与此同时,为提高换热效率,换热器内流体流速同样有所增大,这些改变导致工厂的一些大型换热器经常出现大幅的管束振动,致使换热器的寿命缩短乃至发生破坏问题。基于实际工作经验,工程上往往通过加装固定板等方式减小振动,但该方式缺乏数据和理论的指导,难以高效地改良换热器、避免类似情况的发生。以换热器管束为计算对象,以国标GB/T 151—2014附录C为理论依据,对不同流体参数、换热器结构参数下导致换热器管束振动的各机理(卡门涡街、湍流抖振、流体弹性不稳定性)的相关参数进行导出,包括卡门涡街和湍流抖振的主频率以及发生共振时的振幅、各部位的流体横流速度及发生流体弹性不稳定时的临界横流速度、换热管的固有频率。基于振动参数对换热器中流致振动的主导机理进行定量分析,找到最易导致管束振动的机理。同时通过改变换热器管束的质量、弹性模量、管外径等导出相关振动参数,并分析了换热管结构参数对振动参数的影响,从而找到更高效的减振方案。壳程为液体流时三种机理几乎在相同条件下都会引发振动,其中,卡门旋涡的流体弹性不稳定危害性相对较大;壳程为气体流时卡门旋涡和湍流抖振更易引发振动,其中,卡门旋涡的流体弹性不稳定危害性相对较大。减振措施中改变换热管外径和支承排布对换热管振动特性影响较大。特别地,对工程上通过增加支承减振的经验做法进行了算例分析,发现增加固定件不一定能起到减振效果,反而可能导致管束振动加剧。对蒸汽过热器管流致振动的主导因素分析,及对不同减振措施的比较,为换热器工程设计提供了参考。In recent years,large steam turbine and boiler have been widely used in domestic and foreign power plants,corresponding to the increase of the heat exchanger volume,average pipe span distance,at the same time,in order to improve the heat exchange efficiency,the heat exchanger fluid flow speed also increased.These changes lead to some large heat exchanger plants often large bundle vibration,resulting in the heat exchanger life shortened and even damage.Engineering often reduces vibration based on practical working experience by add⁃ing fixed plates and so on,but in lack of data and theoretical guidance,it is difficult to efficiently improve the heat exchanger to avoid similar situations.Taking the heat exchanger tube bundle as the calculation object and taking the GB/T 151-2014 Appendix C as the theoretical basis,the relevant parameters of various mechanisms(Karmen vortex street,turbulent buf⁃feting and fluid elastic instability)leading to the vibration of the heat exchanger tube bundle under different fluid parameters and heat exchanger structural parameters are derived.It included the main frequency of Karman vor⁃tex street and turbulent buffeting,the amplitude at resonance,the fluid cross-flow velocity at various parts,the critical cross-flow velocity at fluid elastic instability and the natural frequency of the heat exchanger tube.Based on the vibration parameters,the dominant mechanism of flow induced vibration in heat exchanger was quantita⁃tively analyzed,and the mechanism most likely to cause tube bundle vibration was found.At the same time,by changing the mass,elastic modulus and outer diameter of the heat exchanger tube bundle,the relevant vibration parameters were derived,and the influence of the structural parameters of the heat exchange tube on the vibra⁃tion parameters was analyzed,so as to find a more efficient vibration reduction scheme.When the shell range was a liquid flow,the three mechanisms initiate vibrations under almost the same conditions,Karmen vortex and fluid elastic instabili

关 键 词：发电厂 换热器 管束 流致振动 减振 定量分析 主导机理 

分 类 号：TK172[动力工程及工程热物理—热能工程]