国产50MW(60MW)机组轴系异常振动的故障诊断及治理

通过对国产50 MW(60 MW)机组轴系中1#瓦、2#瓦、4#瓦轴承异常振动的机理研究与分析,提出了该机组汽轮机轴承异常振动的原因是由于油膜轴承存在半速涡动,它是自激振动,而发电机转子4#轴承振动是由于发电机转子存在较大的不平衡量,它是强迫振动,针对轴系中存在的两种不同性质的振动提出了处理解决的途径,实践证明本文的分析及处理方法是行之有效的.     

攀钢钒发电厂#1机#6轴承振动故障诊断

攀钢钒发电厂3×100MW机组1#机发电机#6轴承在2010年大修后发现振动偏大.根据现场测量的振动数据分析,初步决定对发电机进行彻底检查.对上次大修后的数据进行复查,并根据解体检查情况判断引起#6轴承振动偏人的主要、次要原因.采取相应的有效处理措施,并根据机组启动效果判断问题原因分析的正确性.给今后机组振动故障的诊断积累了宝贵经验.     

邹县电厂600MW汽轮发电机组异常振动分析及处理

邹县电厂6#机组为山东首台600MW汽轮发电机组,机组振动随运行时间及负荷的增加逐渐向上爬升,5#～7#轴瓦振动严重超标,发电机7Y轴振时常报警,当机组负荷在400～550MW时,5#～7#号轴瓦振动分别为73μm,95μm,81μm,7Y轴振达到了135 mm.本文详细分析了5#～7#号瓦振和7Y轴振的振动特征以及异常振动原因,提出了低压转子和低发对轮同时平衡处理方法,使机组振动达到了优良水平.     

某150MW汽轮机组轴瓦振动超标原因分析及处理

针对某公司150MW汽轮机组低压缸#3轴承振动大、不稳定且有逐渐增强趋势的问题,通过对该机组振动进行全面测试,找到了故障原因,确定了处理方案.处理过程中,在排除了信号故障后,实施了现场高速动平衡试验,振动故障得以消除,机组振动值达到优良范围.该机组的振动特征及处理过程具有代表性,本文给出了分析、诊断的思路和处理方法,可为类似故障的处理提供借鉴.     

基于TMD的风力发电机组降载设计方法

针对山西某风电场44#风电机组在水平垂直于传动链方向的突发性、间歇性振动而导致风电机组振动超限停机。设计了质量阻尼调谐装置(TMD)对风电机组进行减振,并对TMD减振装置的原理和设计流程进行了详细的介绍。同时,设计开发了TMD减振装置,成功应用于风电现场。应用结果表明:设计的质量阻尼调谐装置在机组满发工况下减振效果能达到40%以上,能够减轻风电机组机舱振动幅度,消除风电机组机舱振动故障,减少风电机组的故障停机时间。     

^#2汽轮机^#1瓦瓦振波动的分析及防范

通过对公司2号机组运行中#1瓦瓦振波动的情况进行分析,得出引起振动的原因并提出相应的处理方法。     

110MW汽轮发电机组轴系转子不平衡故障的诊断及治理技术

根据振型分离方法和模态理论的基本思想,对检修后的捷克110 MW汽轮发电机组转子不平衡故障进行了诊断.在工作转速下对轴系各轴承进行实测和分析诊断,得出发电机转子7#瓦振动超标的主要原因是转子存在较大的二阶不平衡分量的激振力,并且在转子激振力作用下发电机轴承座刚度降低,轴承座基础产生差别振动,导致7#瓦垂直振动和轴向振动超过振动标准数倍.这种诊断方法在故障诊断和轴系动平衡领域有着良好的工程应用前景.     

300MW机组振动分析与防范

我公司一期安装2×300MW国产引进型机组,经过增容改造为330MW机组,通过两台机组的试运调试,发现这两台机组都存在振动大的问题,突出表现为4、6、7瓦振动较大,甚至造成无法过临界,降速过临界振动加剧。在试运中通过不断地探索与总结,发现了该类型机组振动的一些原因,另据资料表明,国内同类型机组都存在类似问题,本文在收集有关资料并结合现场运行经验的基础上,对我厂及同类型机组振动情况、原因作了一些分析,提出了在工作中如何防范330MW汽轮机组振动的措施,供参考。     

百年电力3号机组异常振动分析处理

百年电力3号机组大修中进行了增容改造后,机组启动、定速和带负荷过程发生异常振动,严重威胁机组的安全运行.通过频谱分析、振动升降特性和机组带负荷的振动特点等特征对机组的振动故障进行了正确的诊断分析,确认了汽轮机中压缸内的动静摩擦和低压转子一阶和二阶不平衡量的存在是造成的机组异常振动的原因.通过调整2号轴承座的标高和低压转子的一次精确加重,成功消除了机组的振动故障,振动达到优良水平,保证了机组的安全投产运行.     

汽轮发电机组摩擦振动大的分析及对策

摩擦振动是汽轮发电机组的常见的振动故障之一,识别它的特点并及时采取正确的应对措施是非常必要的,本文结合海勃湾发电厂#5机组的摩擦振动大对该问题进行分析探讨。     

Vibration failure in admission pipe of a steam turbine due to flow instability

High vibrations in admission piping of a steam turbine were analyzed. Vibration failure was detected after piping modification as part of upgrading a 300 MW power turbine plant searching for 10% power increment. However, after 1 year operation a vibration malfunction was detected in control valve and fittings of income piping with risk of cracking for maximum output. A study of computational fluid dynamics (CFD) revealed large steam flow instabilities produced by recirculation and high velocity exceeding a critical point. Measurements of natural frequency piping system with the turbine stall and subsequent measurements of frequency and vibration analysis during turbine operation indicated that recirculating flow plays a main role in the vibration problem by resonance. The paper discusses CFD results obtained with a proposed pipe configuration that reduces turbulence effects. Combined pressure slide and diameter increment in piping lead to reduced vibration turbine operation.     

基于时频滤波的汽轮机半速涡动故障成分提取

汽轮机油膜涡动是滑动轴承失稳而产生的自激振动,其振动频率主要表征为转子转频的一半或略小。当油膜涡动频率等于转子一阶临界转速时会导致振动加剧,进而对汽轮机的稳定运行产生严重影响。Gabor变换是一种可逆的联合时频分布方法,其逆变换具有时域信号重构的能力。基于Gabor变换对850 MW汽轮机振动信号进行时频分析,显示反映轴系不稳定的半速涡动成分,进一步对该成分进行时频带通滤波,并基于Gabor逆变换予以时间重构,获取半速涡动成分的峰峰值量化指标,为汽轮机轴承油膜涡动故障提供诊断依据。     

600 MW超临界汽轮机延长混合阀运行时间对机组振动的影响

某电厂600 MW超临界汽轮机2号、3号、4号、5号、6号轴承振动偏大。为解决该问题,在机组运行中,通过对汽轮机带初负荷延长混合阀运行时间来改变汽轮机的进汽方式,使汽轮机充分膨胀,从而改善汽轮机高压缸胀差绝对值,同时也改变了轴承负载,达到降低轴承振动的目的,确保汽轮机振动达到最优状态。     

《汽轮给水泵振动分析》

汽轮给水机组是重要的汽轮辅机之一.本文针对某型汽轮给水机组在调试中出现的振动偏大现象,结合机组振动测试结果,对机组的振动性能进行了细致的分析,找出了主要的原因。本文结果对此类型机组的设计和调试有一定的借鉴意义。     

大型火电机组的振动故障诊断

章回顾癖结了国内外火电机组振动故障诊断的发展状况,指出了目前振动故障诊断研究存在的问题及确定故障诊断知识范围,进行机组一轴系统特性研究的重要, 对大型火电机组振动及性能远程诊断系统进行了介绍,最后指出了振动故障诊断的发方向。     

汽轮机间隙气流激振力分析

基于流体动力学,应用动量定理研究汽轮机直叶片、短扭叶片、长扭叶片以及汽轮机调节级由于间隙引起的气流激振力问题,综合考虑了叶片的各项设计参数并应用理论分析方法导出普遍适用的计算公式,解决了Alford公式中需人为选取效率系数的困难。数值实验的结果表明,所导出的计算公式是可靠的。     

In Situ Detection of Turbine Blade Vibration and Prevention

Turbine blades are the most critical components in any power plant. Failure in even one rogue blade out of hundreds of blades fixed on the rotor leads to colossal damage to the machine. Statistics have shown that low-pressure turbine blades in steam power plants are generally more susceptible to failure compared to high- or intermediate-pressure blades. The mechanism of failures is different in each case and is generally very complex. As a result, a large number of blade failures are not fully understood. Two primary forces acting on the blades are the steady centrifugal force due to rotation and the fluctuating steam bending force. In view of no direct access to monitor the health of the blades through vibration or other means, indirect method using non-contacting probes have been attempted and some are in use in special cases. Largely these methods are expensive and intrusive in nature. They involve placing of sensors in the narrow space inside the turbine casing, routing special signal cables with sealing arrangement and involves difficulties in analyzing shot duration signals from each rotating blades. Unless a diagnostic technique is made simple to implement and whose reliability is proven, power plants will not find it attractive to invest on upgrade for safe operation of the machine. This article is about an innovative method of detecting the presence of blade vibration in operating turbine through vibration signal analysis and prevention through process control. The method is based on vibration analysis of the turbine casing. The casing vibration includes signals associated with the blades of different stages called as blade passing frequency (BPF). When the rotating blades vibrate, the analysis of changes in the BPF is a novel way of diagnosing blade vibrations. Signals captured from operating plants have been analyzed and blade vibrations have been detected and verified with Campbell diagram. Laboratory experiments were carried out on a rotating fan to demonstrate robustness of the diagnostics tool for turbine blades.     

汽轮机非线性间隙气流激振力作用下含裂纹转子的振动特性研究

建立了在汽轮机非线性间隙气流激振力作用下裂纹转子-轴承系统的动力学分析模型,并采用数值积分方法研究此类裂纹转子系统的分岔与混沌特性。利用Poincare截面和分岔图的变化分析汽轮机非线性间隙气流激振力和裂纹深度对系统振动响应特性的影响。分析结果表明：汽轮机非线性间隙气流激振力会使得系统的周期性运动状态提前,且混沌区域发生明显的减小;在浅裂纹时,汽轮机非线性间隙气流激振力对系统的响应起主导作用,且在超临界转速区域出现周期8运动;随着裂纹深度的增加,系统运动的混沌区域逐渐减小几乎消失,在超临界转速区域的逆周期运动演变为较长的周期3运动。研究结果可以作为含裂纹转子在汽轮机非线性间隙气流激振力作用下耦合故障发生的典型特征,也可作为此类耦合故障诊断的依据。     

Failure of a steam turbine rotor due to circumferential crack growth influenced by temperature and steady torsion

High cycle fatigue as a final mechanism of failure in rotating systems, especially steam turbines, is a serious phenomenon. Incomplete information of its effective parameters could lead into catastrophic failure of the rotor. In high cycle fatigue, one of the most effective factors in crack growth is high temperature. In fact, a high-temperature change alters mechanical characteristics of material including their fracture mechanic. Therefore, the investigation of crack growth of fatigue and crack front development in various steam temperatures requires a careful consideration of the different parts of the rotor along the steam turbine rotor. This study investigated the propagation of a circumferential crack at three points of the turbine rotor in 24,149 and 260 ^∘ C under the influence of rotor weight loading. In addition, the study addressed torque as another important parameter in crack growth which is caused by steam pressure in the turbine. Through the obtained results, a crack front shape is achieved which can be used in rotor vibration analysis. Reviewing the related literature indicated that crack growth rate associated with alternative mode I loading in the presence of steady mode III loading is reduced. To investigation this phenomenon, the study considered roughness induced crack closure due to steady torsion and its corresponding equations by analytical method were derived. Finally, the study investigated the influence of roughness on crack growth rate in abovementioned three points of the rotor.     

振动监测系统的可调增益技术与实现

文章设计了一种具有可调增益功能的振动监测系统。首先从监测层和测量层两个方面提出了振动监测系统的整体框架,之后给出了硬件系统和软件系统的设计方法及软件实现代码,利用控制芯片和可调增益放大器,在监测系统中整合了一套可根据采集信号幅值大小调整增益的数据采集装置;利用模拟信号发生器对不加增益和设置可调增益之后的两种信号进行了对比分析,并在汽轮发电机组实际工况下进行了振动信号采集。结果表明,具备可调增益功能的振动监测系统可有效提高采集信号的信噪比,提高汽轮发电机组的振动监测能力。