管道振动分析与减振对策

浙江科技学院本科毕业设计（论文）1浙江科技学院本科学生毕业设计（论文）题目管道振动分析与减振对策系别机械与汽车工程学院专业班级材料成型及控制工程A班姓名刘际灯学号10212057指导教师刘淑莲浙江科技学院本科毕业设计（论文）22006年6月6日浙江科技学院本科毕业设计（论文）3摘要在石油化工等工矿企业中，广泛使用管道输送流体。在一定压力和流速的流体作用下这些管道壁上均会产生流体动压力。非定常的管流会引起管道的振动也就是管流脉动。管流脉动是引起管道及附属设备的振动的主要原因，导致管道结构和管路附件产生疲劳破坏，甚至造成严重事故，是管路系统的主要故障。某炼化公司的甲胺泵管线振动强烈，已多次引起安全阀根部和导压板根部焊缝撕裂，连接法兰密封失效，高压高浓度的甲胺液外泄。本文对在单泵运行和双泵同时运行时的某炼化厂的高压甲胺泵管线振动分别进行了测试，通过对各个管路系统的不同测点的振动频谱分析，给出了振动的起因是压力脉动。当压力脉动的频率或者其倍数正好与管线的固有频率接近而导致共振时，管线就会发生强烈的振动。不发生共振时，管线振动就较小。因此提出了相应的减振措施：在现有支承架与管子的中间垫上防振橡胶垫，改变管线的固有频率，使压力脉动的频率及其倍频与管线的固有频率不相吻合。在泵的出口处加装蓄能器或者空气罐，用来吸收压力脉动，并根据条件设计了蓄能器。关键词：管流脉动振动甲胺泵管路浙江科技学院本科毕业设计（论文）4AbstractPipeswerewidelyusedtotransportliquidinmanypetrochemicalfactoriesandche-micalplant.Underthepressureoffluidwithcertainpressureandvelocity,thefluiddyna-micpressurepulsationwillbecreatedinthewallofthepipe.Whenthefluidflowsinun-unsteadyconditiontheunconstantflowwouldexcitepipeabnormalvibration-itwasalsocalledflowpulsation.Flowpulsation,themainreasonforthevibrationofpipeandattac-chedequipment,educedthefatiguefailureofpipeandattachedequipment,whichevenresultinfatalaccident.Inarefinery,theintensivevibrationofthemethylaminebumppipelinehadcausedmanyproblems,forexampletearingofweldinglineattherootofsafetyvalve,sealfailuresofconnectingflangewhichcausingleakageofmethylaminefluidwithhighpressureandconcentration.Inthispaper,thevibrationwastestedtoinvestigatethevibrationfaultonmethylaminebumppipelineinarefinerywhensinglepumpordoublepumpsworked.Byspectrumanalysisofdifferentmeasuringpoint,thecauseofstrongvibrationwasfoundout:pipewouldvibratestronglyifthefrequencyofthepressurepulsationormultipleofitamounttothenaturalfrequencyofthepipeline.Andinothercase,thevibrationwouldnotbestrong.Accordingtothis,thesolutionsweregiven:changingthenaturalfrequencyofthepipelinebyaddingvibrationproofcushion;addingenergystorageoraircontainertoabsorbthepressurepulsation.Finally,theenergystoragewasdesignedattheoutletofthepumpfordrinkingpressurefluctuationdown.Keyword:pipefluidpulsation,vibration,methylaminebumppipeline浙江科技学院本科毕业设计（论文）5目录摘要····································································································ⅠAbstract································································································Ⅱ1绪论··································································································11.1课题背景···················································································11.2研究现状···················································································11.2.1国外研究现状分析·······························································11.2.2国内研究现状分析·······························································21.3研究现状···················································································32管道振动理论······················································································42.1引起管道振动的原因····································································42.1.1动力平衡性差或基础设计不当引起的管道振动···························42.1.2管流脉动引起的管道振动······················································42.1.3共振·················································································42.2管流脉动机理·············································································42.3管道故障诊断的步骤····································································52.4管道减振技术·············································································52.4.1压力脉动的消减··································································63振动测试····························································································73.1振动测试试验·············································································73.1.1测试系统···········································································73.1.2气流脉动引起的管道振动······················································83.1.3共振·················································································83.2振动信号分析···········································································103.2.1系统固有频率的测量…………………………………………………103.2.2强迫振动频率的测量…………………………………………………113.2.3电机在正常工作下并在外界激励下的频谱图………………………123.2.4整周期采样的实现……………………………………………………134管线振动的测试和分析········································································164.1现场分析·················································································164.1.1现场状况·········································································164.1.2现场测试系统的组成··························································164.1.3振动测试方案···································································174.1.4管线固有频率的测试··························································174.2减振措施·················································································34浙江科技学院本科毕业设计（论文）64.3蓄能器的设计···········································································354.3.1蓄能器的选型···································································354.3.2皮囊式蓄能器的结构及工作原理···········································354.3.3蓄能器容积的设计··············