Design-Optimization-of-Shell-and-Tube-Heat-Exchang

ModernMechanicalEngineering,2011,1,6-11doi:10.4236/mme.2011.11002PublishedOnlineAugust2011()Copyright©2011SciRes.MMEDesignOptimizationofShellandTubeHeatExchangerbyVibrationAnalysisShravanH.Gawande1,AppasahebA.Keste1,LaxmanG.Navale1,MilindkumarR.Nandgaonkar1,VaishaliJ.Sonawane1,UmeshB.Ubarhande21DepartmentofMechanicalEngineering,ModernEducationSociety’sCollegeofEngineering,Pune,India2PEMDesign(R&D),AlfaLaval(India)Ltd.,Pune,IndiaE-mail:[e-mail]23,2011;revisedAugust7,2011;acceptedAugust15,2011AbstractInthispaperasimplifiedapproachtooptimizethedesignofShellTubeHeatExchanger[STHE]byflowinducedvibrationanalysis[FVA]ispresented.ThevibrationanalysisofSTHEhelpsinachievingoptimiza-tionindesignbypreventionoftubefailurecausedduetoflowinducedvibration.ThemainreasonfortubefailureduetoflowinducedvibrationisincreasedsizeofSTHE.ItisfoundthatincaseofincreasedsizeofSTHE,thesurfaceareaandnumberoftubesincreases,thustheunderstandingandanalysisofvibrationbe-comesaverydifficulttask.Againitisfoundthatflowinducedvibrationanalysisisconsideredasanintegralpartofmechanical&thermaldesignofSTHE.Thedetaileddesign,fabrication,testingandanalysisworkwascarriedoutatAlfaLaval(India),Ltd.,Pune-10.Keywords:HeatExchanger,Flow-InducedVibration,TEMA,HTRI1.IntroductionTheprincipalculpritinflowinducedvibrationoftubesofSTHEistheunsupportedtubelengthssubjectedtolargeflowratesonshellside.TheincreasedsizeofSTHEduetolargeflowratesisresponsibleforvibrationoftubes,whichfurtherleadstotubefailure.AlsothedesignofSTHEismadesaferbymodifyingshelltypeand/orbafflesstyleandbaffledesign.Thus,thevibrationanalysisisofutmostimportanceindesignofSTHE.So,theflowinducedvibrationanalysisisconsideredasanintegralpartofthermaldesign.Thecharacteristicsofvortexsheddingfromtubebankswithcloselymountedserratedfinwasinvestigatedin[1]wheretherelationshipbetweentheStrouhalnumberde-finedbytheequivalentdiameterasthecharacteristiclengthofafinnedtubeinthetubebanksandtheStrouhalnumbermapforbare-tubebankswasexamined.Whereasin[2]theauthorhaspresentedvariousoutletconditionsofashellandtubeheatexchangertheoreticallyandex-perimentallyinwhichitisobservedthatprimeparametergeometryofoutletaffectstheperformance,maintenanceandlifespanofaverticalshellandtubeevaporator.Theheattransferenhancementhasbeenachievedin[3],bymodifyingtheconfigurationofashell-and-tubeheatex-changer,throughtheinstallationofsealersintheshell-side.Thegapsbetweenthebaffleplatesandshellisblockedbythesealers,whicheffectivelydecreasestheshort-circuitflowintheshell-side.Theoriginalshort-circuitflowthenparticipatesinheattransfer,whichin-tensifiestheheattransferperformanceinsidetheheatexchanger.Theuseofanon-traditionaloptimizationtech-nique;calledParticleSwarmOptimization(PSO),fordesignoptimizationofshell-and-tubeheatexchangersfromeconomicviewpointisexploredin[4]inwhichminimizationoftotalannualcostisconsideredasanob-jectivefunction.Threedesignvariablessuchasshellinternaldiameter,outertubediameterandbafflespacingareconsideredforoptimization.Twotubelayoutsviz.triangleandsquarearealsoconsideredforoptimization.TheresultsofoptimizationusingPSOtechniquearecomparedwiththoseobtainedbyusingGeneticAlgo-rithm(GA).Alsotheoptimizationofthedesignofshell-and-tubeheatexchangersbyminimizationofthethermalsurfaceoftheequipment,forcertainminimumexcessareaandmaximumpressuredrops,consideringdiscretedecisionvariablesispresentedin[5].Theheattransfercoefficientandpressuredropontheshellsideofashell-and-tubeheatexchangerhasbeenobtainedexperi-mentallyin[6]forthreedifferenttypesofcoppertubes.S.H.GAWANDEETAL.Copyright©2011SciRes.MME7ThecomprehensiveexperimentalinvestigationontheaugmentationofheattransfercoefficientsandpressuredropduringcondensationofHFC-134ainahorizontaltubeatthepresenceofdifferenttwistedtapeinsertswascarriedoutin[7].Theexperimentswereperformedforaplaintubeandfourtubeswithtwistedtapesinsertsof6,9,12and15twistratios.Similarly,thenumericalandex-perimentalinvestigationstounderstandconvectiveheattransferfromasingleroundpipecoiledinrectangularpatternarepresentedin[8]wherethestudiedheatex-changerswerecomposedwithinnerandoutercoilssothattheexteriorflowisverysimilartoflowwithintube-bundles.Theinnerandoutercoilsoftheheatexchangersareinturncomposedofbendsandstraightportions.Theinvestigationoftheflowfieldandtheheattransferchar-acteristicsofashell-and-tubeheatexchangerforthecoolingofsyngaswerecarriedoutin[9]inwhichthefinitevolumemethodbasedonFLUENTsoftwareandtheturbulencemodelwasadoptedformodelingturbulentflow.Thepressuredrop,thetemperaturedistributionandthevariationoflocalheattransferwerestudiedundertheeffectsofthesyngascomponentsandtheoperatingpre-ssure,andtheeffectofthearrangementofthebafflesontheheattransferhasbeenstudied.Inthisproposedworkdesign,development&testingofSTHEiscarriedout.Alongwiththeparametercon-sideredin[1-8],vibrationanalysisisperformedtoopti-mizedunsupportedspanoftubebyusingHTRIsoftware.DetailoverviewonworkcarriedoutbyresearchersispresentedinSection1,Section2&3statesmechanicsofflow-induced