常减压装置离心泵震动问题的解决

离心泵是石油化工装置中比较常见的设备，在离心泵的使用过程中，离心泵振动的现象是常见的故障问题，振动是评价泵运行的一个重要指标，本文主要对泵振动原因进行了分析，利用经济可行的改造，解决了常减压装置泵振动的问题，达到了预期效果。     

离心泵振动因素剖析及解决方法

纯梁采油厂采油一矿注水管理区管理着两座离心泵站,在离心泵的使用过程中,发现振动是造成缩短离心泵大修周期,增加能源浪费的主原因。为了提高离心泵的使用寿命,同时能使其高效率运行,以达到最佳工况运行状态,从离心泵的装配原因、运行过程中和其它三个方面对高压离心泵出现振动的因素和解决方法进行分析。     

离心泵常见故障分析与处理

离心泵在运转过程中，难免会出现漏水、压力低、不出水等各种各样的故障，对生产、生活的正常进行造成影响。因而，如何提高泵运转的可靠性、寿命及效率，以及对出现的故障如何进行及时准确的判断处理，是保证生产平稳运行的熏手段。作者通过对自己多年从事离心泵维修经验的总结，认真分析离心泵产生故障的原因，提出了自己的观点和处理方案，供同行业相关人员参考。     

机械振动异常分析与处理方法

汽轮机与离心泵发生的异常振动现象,是整个机械系统中非常常见的一类故障,同时也是众多机械故障中很难弄清产生原因的故障之一,汽轮机振动异常的现象预示着机械故障的产生同时也在很大程度上反映出系统运行的时候存在隐患和风险。在下面文中,笔者将从个人的实践工作经验及其有关的技术知识层面出发,详细对汽轮机以及离心泵的异常振动问题以及故障判断处理等几个方面进行分析和讨论。     

浅论离心泵振动原因与其处理

离心泵是工厂生产中常用的设备之一,在流体输送中发挥着重要作用,但是在离心泵的使用过程中经常会出现故障问题,严重影响工作效率,离心泵的振动是最为常见的故障之一,由于造成离心泵振动的原因较多,因此离心泵振动处理要全面了解振动原因,有针对性地制定处理策略。本文分析了离心泵振动的原因,并提出了相应的处理方法。     

基于补偿距离评估和一维卷积神经网络的离心泵故障快速智能识别方法

一维卷积神经网络可适用于振动等一维信号的识别与分类,但将其直接应用于机械故障诊断时小样本训练条件下的识别准确率与识别速度是其亟需解决的问题。针对上述问题,提出一种基于补偿距离评估和一维卷积神经网络的离心泵故障快速智能识别方法。基于离心泵振动分析与故障诊断理论,通过提取时域、频域、能量及熵特征来构造混合域全特征集,充分挖掘训练样本中的故障信息,提高单个训练样本的利用率,使故障识别模型具备小样本训练的能力;通过补偿距离评估方法对全特征集进行降维优化,在有效保留故障特征信息的同时显著降低特征维度,使特征构造及故障识别模型具备快速计算的能力;通过训练样本的降维后特征进行一维卷积神经网络的训练,进而构建故障智能识别模型,保存模型并将其用于离心泵故障分析。经某石化离心泵的抽空和滚动轴承损伤两个故障案例验证,该方法在小样本训练条件下识别准确率达到98%以上,单组数据识别时间小于3 s,可满足工程中离心泵故障实时智能识别的需求。     

风机不平衡与基础松动故障共存时的振动分析

本文阐述了Ｄ２８型化铁炉除尘风机，在机组故障振动时的监测和分析诊断过程，在排除了不平衡、不对中、转子弯曲等各种次要因素后，最终，缍找到逐步疏松着的基础是造成振动的主要因素，从根本上解决了问题，使机组恢复正常运行。     

离心泵常见故障分析与处理

离心泵运转过程中，难免会出现各种各样的故障。因而，如何提高泵运转的可靠性、寿命及效率，以及对发生的故障及时准确的判断处理，是保证生产平稳运行的重要手段。     

离心泵常见故障分析与处理

离心泵运转过程中，难免会出现各种各样的故障。因而，如何提高泵运转的可靠性、寿命及效率，以及对发生的故障及时准确的判断处理，是保证生产平稳运行的重要手段。     

多传感器数据下基于MFDFA-BP的离心泵空化致振故障分析EI北大核心CSCD

针对单传感器所测数据存在的不全面性及离心泵故障信号的非线性非平稳性等问题,提出多传感器数据下基于多重分形去趋势波动分析法(multi-fractal detrended fluctuation analysis,MFDFA)与BP(back propagation,BP)神经网络的离心泵空化致振故障分析方法。采用MFDFA法对离心泵5种不同工况下的8类实测信号进行分析,提取多重分形谱特征参数Δf、α_(0)、Δα、α_(min)及α_(max)作为故障特征向量,并结合BP神经网络进行单传感器信号故障诊断,优选识别率较佳的信号拼接构成多传感器特征向量,进而开展多传感器离心泵空化致振故障研究。结果表明:MFDFA法提取的多重分形谱特征参数能准确反映泵的运行状态,其中Δf、Δα以及α_(max)等参数对故障分类效果更好;泵振动、扭矩及电机振动等信号对故障本质的反映更准确;在此基础上形成的多传感器故障诊断模型准确率比单传感器提升了13%以上,为离心泵不同程度空化故障的状态识别提供了一种新的方法。     

叶轮空蚀状态下离心泵振动特性分析

空蚀是指空化过程中产生的空泡溃灭引起过流表面材料损坏的现象。为研究离心泵叶轮空蚀后的振动信号特征,选用IS-50-160-00单级单吸离心泵为试验对象,基于虚拟仪器技术搭建试验泵系统。测得离心泵空蚀条件下的振动信号,采用均方根(RMS)分析、峭度(K)分析两种统计方法对发生空蚀后的离心泵振动信号的平均能量、冲击波能量进行分析,采用短时傅里叶变换(STFT)分析了振动信号的时频域特性。分析结果表明:空蚀条件下整体来看基座方向和轴向方向振动幅值较大且都是无规则振动,而横向方向和纵向方向上的振动信号振幅相对较小;振动信号的能量随着流量的增大呈现先减小后平稳再增加的趋势,空蚀增加了振动信号的能量值;空蚀加剧了液体对离心泵的冲击使得振动信号峭度值增加,且基座方向峭度值大于3可作为空蚀故障的诊断参考标准;通过时频谱分析可知空蚀发生后流体可能对离心泵存在冲击波及冲击波导致的脉冲信号,且空蚀后产生了高频振动信号,高频带的振动信号可为离心泵空蚀故障诊断提供参考。研究叶轮空蚀后离心泵振动信号的特征有助于及时发现离心泵空蚀故障的发生,从而调整运行参数,以免造成严重后果。     

运行工况对离心泵振动影响的试验研究

船用设备的特点是多工况运行,为研究变工况对船用离心泵振动的影响,对离心泵组进行试验研究,从转速、流量等参数变化进行综合分析,试验结果验证转速-振动经验公式,并总结出离心泵振动水平与转速的4～9次幂成正比;流量变化对低、高频振动的影响比中频段的影响更为明显,在特征频率叶频处表现得尤为突出;在需要小流量工况时,应采用调节降低转速代替阀门调节等对离心泵低噪声运行的有利措施。     

Rotational torsion fatigue failure of an engine driven fuel pump coupling

Between 2005 and 2007 serious flight safety concerns arose when a small fleet of single engine basic trainer aircraft experienced five critical failures of engine driven fuel pump (EDFP) couplings, and a further instance of a cracked coupling. Consequent investigations showed that the coupling fractures were likely to have been caused by a combination of reverse torsional loading and bending. Engine ground runs were then carried out to evaluate linear and torsional engine vibration levels in the drive train affecting the fuel pumps. Analysis of the vibration data indicated that engines, which had caused pump‐coupling failures exhibited high‐amplitude torsional vibration at certain power settings. The excessive vibration level was eventually attributed to detuning of the crankshaft counterweight dampers. This investigation resulted in a change to the maintenance practises on the aircraft in question and no fuel pump failures have occurred since December 2008.     

"双时域四谱"法在振动信号分析中的应用

准确地提取各种典型故障的振动信号的时频域特征是进行机械故障诊断的关键．为了综合提高诊断能力,突出信号特征,本文介绍了一种信号分析与故障诊断新方法,该方法以“双时域四谱”综合诊断法为理论基础．具体应用双时域（原始时域和包络时域分析）和四频域（功率谱分析、细化谱分析、解调谱分析、倒频谱分析）的振动诊断方法,综合各自的诊断优势,对用特征振动信号进行诊断的问题进行了研究,并阐述了这些方法的特点和功能．     

离心泵流动诱发振动特性数值计算分析

建立了一种适用于离心泵等叶轮机械流动诱发振动工程计算的数值模型和方法流程。基于URANS方程求解泵内流场,在流场非定常计算过程中输出叶轮所受时域脉动压力,将脉动压力通过FFT转换到频谱并以之作为泵组结构的振动激励源,采用隐式有限元方法进行泵组结构振动响应的计算。计算方法通过测试得到验证,可以用于离心泵流动诱发振动特性的计算评估和低噪声设计。完成了原型和改进型船用海水泵在设计工况下流动诱发振动响应的计算,分析了两型泵流场、振动激励源和振动响应等特性。计算表明,泵的改型设计显著减小泵内压力脉动以及振动激励源,改型泵振动小于原泵。     

A Comparative Study on the Performance Characteristics of Centrifugal and Progressive Cavity Slurry Pumps with High Concentration Fly Ash Slurries

Slurry pumps are extensively used in the hydraulic transportation of fly ash slurries through pipes in thermal power plants. Today, a wide range of slurry pumps are available and the most commonly used pumps are broadly classified into two main categories, namely, positive displacement and centrifugal pumps. These two types of pumps differ considerably in construction as well as in operating principle compared to the conventional pumps. The aim of the present study is to compare the performance characteristics of these two different types of pumps operating with high concentration fly ash slurries. For each type, the performance characteristics have been experimentally evaluated at the rated speed with water as well as with fly ash slurries in the concentration range of 50 to 70% by weight. The pump total head, overall efficiency, and pump input power as a function of the flow rate have been measured. The results obtained from the centrifugal slurry pump performance show that at rated speed, the head and efficiency of the pump decrease with an increase in solid concentration and the effect is strongly dependent on slurry properties. The pump input power also increases monotonically with an increase in solid concentration. In the case of progressive cavity screw pump, pump performance characteristics and behavior were completely different compared to the centrifugal slurry pump. At rated speed, the head developed and the efficiency of the pump improved with an increase in solid concentration for progressive cavity screw pump.     

Sind Trockenläufer wirklich die Lösung aller Probleme?

With this article the author intents to generate the awareness, that dry pumps due to its pump principle, performance characteristic and physical limitations not always to be seen as the solution to all challenges in vacuum technology out there. Monitoring and protective measures are resulting in more sensitivity to failures and operational errors, higher operating and maintenance cost as well as a certain knowledge about safe operation of dry pumps for system manufacturers and users is required in comparison to the classical rotary vane pumps. The requirement for oil free process chambers and apparatus were the major push to develop and improve dry pump technology but despite this trend the rotary vane pumps is for certain applications the pump of choice will be still around for quite some time.     

Correction: Sind Trockenläufer wirklich die Lösung aller Probleme?

With this article the author intents to generate the awareness, that dry pumps due to its pump principle, performance characteristic and physical limitations not always to be seen as the solution to all challenges in vacuum technology out there. Monitoring and protective measures are resulting in more sensitivity to failures and operational errors, higher operating and maintenance cost as well as a certain knowledge about safe operation of dry pumps for system manufacturers and users is required in comparison to the classical rotary vane pumps. The requirement for oil free process chambers and apparatus were the major push to develop and improve dry pump technology but despite this trend the rotary vane pumps is for certain applications the pump of choice will be still around for quite some time.     

滑阀泵不平衡力的分析

滑阀真空泵是一种容积式真空泵,在工业领域中广泛应用。该泵的旋转活塞平衡长期以来无精确的计算方法,其旋转活塞产生的离心力引起泵的大振动。因此降低该泵的振动长期以来是各国设计者们追寻的目标。文章在分析滑阀泵旋转活塞惯性力的基础上,从理论上分析比较了H－150A,H－150型国产单缸泵及英国GENERAL公司的GKT－300AB型三缸结构滑阀泵的平衡效果。在滑阀泵动平衡的发展方向上提出了自己的看法。     

叶片泵振动机理特性分析及改进设计

机械设备振动和设备组成、工作机理、工作状态等息息相关,船用常见设备如水泵、风机等由于工作机理各不相同,其振动频率特性也各不相同。通过对旋转类设备振动特征进行对比分析,分析设备主要振源及其成因,提出设备改进方向,并进行针对性改进设计,试验结果表明,取得了良好的效果。