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1、Energy-EfficientFluidFlowIntroductionPumpsandfansmovefluidsinawidevarietyofapplications.Carefulanalysiscanimprovetheenergyefficiencyofmostpumpandfansystems.Thischapterdiscussesfundamentalsoffluidflowsystems,withanemphasisonenergy-efficientdesign,retrofitandopera
2、tion.Thischapterincludes:·Derivationofthefluidworkequation·Methodstocalculatepressurelossthroughpipesandfittings·Introductiontopipingandductsystemdesign·Keyprinciplesfordesigningandoperatinglow-energyfluidflowsystemsPrinciplesofEnergy-EfficientFluidFlowEnergyBal
3、anceApproachTheworkrequiredtomoveafluidthroughapipeorductcanbederivedfromanenergybalanceonthesystem.Theelectricalpowertoapump/fan,We,is:We=VDPtotal/[Effpump/fanxEffdrivexEffmotor]whereVisthevolumeflowrate,DPtotalisthetotalpressurerisecreatedbythepump/fanandEffpu
4、mp/fan,Effdrive,andEffmotoraretheefficienciesofthepump/fan,driveandelectricalmotor.Theenergybalanceequationshowsthatelectricalpowerisconvertedintofluidpowerintheformofavolumeflowrateoffluidraisedtoapressuregreatenoughtoovercomefrictionandinlet/outletrequirements
5、.Inaddition,someelectricalpowerisconvertedtoheatratherthanfluidworkduetoinefficienciesofthepump/fan,driveandmotor.Thus,theenergybalanceequationisalsoaguidetoimprovingtheenergy-efficiencyoffluidflowsystems:·Reducevolumeflowrate·Reducerequiredpump/fanheadoDPstatic
6、oDPvelocityoDPelevationoDPfriction·Increasepump/fan,driveandmotorefficiencyEnergy-EfficientFluidFlowSystems77OpportunitiesforImprovingTheEnergy-EfficiencyofFluidFlowSystemsTheseprinciplescanbeorganizedusingtheinside-outapproach,whichsequentiallyreducesend-useene
7、rgy,distributionenergy,andprimaryconversionenergy.Usingtheseprinciples,commonopportunitiestocost-effectivelyimprovetheenergyefficiencyoffluidflowsystemsinclude:·EndUseoDecreaseelevationheadoRunpumps/fansslowerandlonger·DistributionoIncreasepipe/ductdiameteroUses
8、mootherpipe/ductoUselowfrictionfittingsoReducepipe/ductlengthandturns·ConversionoReduceentrance/exitheadlossoForfixedflow,controlflowbytrimmingpumpimpellororslowingfa
