化工过程机械专业-研究生专业英语讲座课件

ProcessTechnologyChapter13UtilitySystemsZhengdongWang(王正东)Room333,Bldg.17,Tel.:64253513zdwang@1ProcessTechnologyChapter13ZhUtilitySystemsaroundYouPowersupplysystem(electricity)Tapwatersystem(runningwater)GassupplysystemTelephonelineInternetconnectionsystem(ISP,ADSL)CableTVsystemGlobalpositioningsystem(GPS)Utilitiesbillingsystem2UtilitySystemsaroundYouPoweObjectives–todescribeBasiccomponentsofasteamsystemarawwatersystemafirewatersystemacoolingwatersystemanairsystemanitrogensystemagassystemanelectricalsystemanindustrialsewersystemaprocessrefrigerationsystemareliefandflaresystem3Objectives–todescribeBasicUtilityBoiler(Wujing)4UtilityBoiler(Wujing)4Coalfiredboiler(Waigaoqiao)5Coalfiredboiler(Waigaoqiao)ProvancePowerPlant6ProvancePowerPlant6IntroductiontoProcessSystemsChemicalplantsandrefineriesincludeuniquecombinationsofequipmentandsystemsthatareusedtoseparatematerialsintopureorrelativelypureproducts.Examplesofprocesssystemsincludereactions,distillation,absorbing/stripping,adsorption/drying,crystallization,evaporation,extrusion,extraction,filtering,screening,andutilitysystems.Plantutilitysystemstypicallyinclude,steamgeneration,compressedairandgases,watertreatment,andcoolingtoweroperations.7IntroductiontoProcessSystemSteamGenerationSystemsBoiler(firetubeorwatertube)Steamheadersystem(low,mediumandhighpressure)Condensatereturnsystem(steamtraps,valves,piping,pumps)DeaeratorsystemSteamsystemscanincludesuperhighpressure(SHP)steamgenerationanddistribution,highpressure(HP)steam,mediumpressure(MP)steamandlowpressure(LP)steam

8SteamGenerationSystemsBoilerSteamGenerationSystemsSuperHighPressure(1000-1200psig)HighPressureSteamSystem(400-800psig)MediumPressureSteamSystem(180to200psig)

LowPressureSteam(50-60psig)*1psi=6895Pa=0.006895MPa=0.06895bar；1bar=14.50psi9SteamGenerationSystemsSuperCondensateRecoverySystem

Thecondensaterecoverysystemisseparatedintocleanandsuspect(dirty)condensatesections.Cleancondensateisroutedtothedeaerator.Suspectcondensateiscollectedfromsteamuserswheretheprocesssidepressureishigherthanthesteampressure.10CondensateRecoverySystemRawWaterandFireWaterSystemThenormalplantsupplyfortherawwater(RW;usedforallpurposesthroughouttheplant)andfirewater(FW;usedonlyinspecificunitssuchasboilers,andusuallymustbetreatedforpurity)systemscomesfromastoragereservoirthatissuppliedfrommunicipalsourcesorlocalriversandlakes.Rawwaterissuppliedtotheunitsintheplantbypumps.Allpumpscanberemotelystartedfromautility'sunitcontrolservice.11RawWaterandFireWaterSysteWaterSystems12WaterSystems12BoilerFeedWaterTreatmentBoilerfeedwatertreatmentistheprocessbywhichsuspendedanddissolvedsolidsareremovedfromthewasteusedinaplant.Cleancondensateanddemineralizedmakeupwateraredeaeratedinordertosupplyboilerfeedwater(BFW)tomultipleBFWpumps.Twoorthreepumpsareusedinthepump-aroundoperation.Theprimarypumptypicallyhasoneortwobackuppumpsthatareplacedinstandbymode.13BoilerFeedWaterTreatmentBoilerFeedWater14BoilerFeedWater14CoolingWaterSystem

Thecoolingwater(CW)systemisusedforcoolingthevariouspiecesofequipmentinthefacilityinaclosedcoolingsystem.Thecoolingwatersystemisdividedintotwocomplementarycircuits.Onecircuitoperatesonaonce-throughbasis;theotherallowsthereuseofwatertocoolasecondtrain,afteruseforcoolingthefirsttrain.15CoolingWaterSystemTheAirSystems

Utilityandinstrumentairarebothsuppliedfromcentrallylocatedaircompressors.Driversforthecompressorsarearrangedsothatthelossofpowerorsteamwillnotinterruptthesupplyofcriticalinstrumentair.Someplantshaveadditionaldieseldrivencompressorsincasethetwoutilitiesarenotavailableatthesametime.16AirSystemsUtilityandiNitrogenSystemsNitrogengasisusuallygeneratedintheplantorpurchasedfromasupplycompany.Ifpurchased,itisusuallydeliveredbyhigh-pressurepipeline.Pipelinepressuresrunfrom300to600psig.Thesuppliermayownandoperatethemeterstation,whichformsthebillingbasisforthepurchaseofnitrogen.17NitrogenSystemsNitrogenNaturalGasSystemMostindustrialmanufacturer'spurchasenaturalgas(NG)fromsuppliers.Ahigh-pressurepipelinegenerallydeliversgastotheplant.Apressureletdownstationlocatednearoneoftheplantentrancesmetersflowtotheplant.Theletdownstationconsistsofmultiplecontrolvalves,twoofwhicharenormallyinserviceforbackup.Additionalvalvesareprovidedforpeakloadssuchasunitstartups.Theletdown/metercontrolvalveisinoperationatalltimes.Asecondvalveopenswhentheflowrateishighandclonesatlowflowrates,therebymakingpossiblemoreaccuratemeteringofthegasflow.

18NaturalGasSystemMostElectricalSystemsThepowerreceivedfromelectricsupplycompaniesisgenerallyatvoltagelevelsof100to160kV.Atmanyplants,thisistransformeddownTo13.8kVfordistributionwithintheplant.Attheunits,the13.8kVissteppeddownto4160Vfor-useonlargemotors(200-10,000hp).The13.8kVisalsotransformedto480V,themostcommonvoltageinmanyplants,andfinallyto240Vand120Vforheating,lighting,andfractionalhorsepowermotors.19ElectricalSystemsThepoSteamSystems

SteamhasbeenusedasasourceofheatandaconveyorofenergysincetheIndustrialRevolution.Itisproducedbyboilingwateranditstemperatureorheatvaluecanbeeasilydeterminedbecauseitgenerallycorrespondstothepressureinthesystem.Steamcarrieslargeamountsofenergyinsmallmassflowrates;theenergyofsteamisreadilytransformedintomechanicalorheatenergyuponcondensation.20SteamSystemsSteamhasbSteamDistributionSystem21SteamDistributionSystem21IndustrialSewerSystemAplantsewersystemcollectsalldrains(waterandprocessfluids)fromtheprocessunits.Allwateriscollectedinaseriesofditchesandroutedtotheplantwastetreatmentarea.UnitsthathavehydrocarbonsthatwillremainintheliquidphaseatambienttemperatureshaveanAPIseparator,whichseparatestheoilphasefromthewaterphasebeforeroutingthewatertotheplantsewersystem.Removedoilisrerunorusedforfuel.Someplasticunitshaveonlyasimplesystemtoremoveoilandpelletsbeforesendingthesewerwatertotheplantsystem.22IndustrialSewerSystemARefrigerationSystem

Heatingandcoolingaretwoimportantaspectsinmodernprocesscontrol.Refrigerationsystems,suchasairconditioningareusedtoprovidecoolingtoindustrialapplications.Refrigerationunitsarecomposedofacompressor(high-pressurerefrigerationgas),aheatexchanger(coolingtower),areceiver,anexpansionvalve(low-pressurerefrigerationliquid),andanotherheatexchanger(evaporator—low-pressurerefrigerantgas).

23RefrigerationSystemHeatSimpleRefrigerationSystem24SimpleRefrigerationSystem24RefrigerationCycle25RefrigerationCycle25ReliefandFlareSystemFlaresystemsareusedtosafelyremoveexcesshydrocarbonsfromavarietyofplantprocesses.Flaresystemsarecomposedofacomplexnetworkofpipesandheadersconnectingtoaknockoutdrumandflare.Governmentallawsandregulationsrequiretheflaretobelocatedasafedistancefromtheoperatingunitsandpopulatedareas.26ReliefandFlareSystemFlaresFlareSystem27FlareSystem27StorageSystemsTanksofvarioustypesareusedforthestorageofrawmaterialsandfinishedproducts.Sincetheyrepr