Process safety 過程安全介紹

ProcessSafety字?jǐn)?shù)1847Processsafetyfocusesonpreventingfires,explosionsandaccidentalchemicalreleasesinchemicalprocessfacilitiesorotherfacilitiesdealingwithhazardousmaterialssuchasrefineries,andoilandgas(onshoreandoffshore)productioninstallations.Processsafetygenerallyreferstothepreventionofunintentionalreleasesofchemicals,energy,orotherpotentiallydangerousmaterials(includingsteam)duringthecourseofchemicalprocessesthatcanhaveaseriouseffecttotheplantandenvironment.Processsafetyinvolves,forexample,thepreventionofleaks,spills,equipmentmalfunction,over-pressures,over-temperatures,corrosion,metalfatigueandothersimilarconditions.Processsafetyprogramsfocusondesignandengineeringoffacilities,maintenanceofequipment,effectivealarms,effectivecontrolpoints,proceduresandtraining.Itissometimesusefultoconsiderprocesssafetyastheoutcomeorresultofawiderangeoftechnical,managementandoperationaldisciplinescomingtogetherinanorganizedway.Processsafetychemistswillexamineboth:Desiredchemicalreaction,usingareactioncalorimeter.Undesiredchemicalreaction,usingoneormoreof:Differentialscanningcalorimeter?Reactivescreeningdevice?AdiabaticcalorimeterTheseinstrumentsaretypicallyusedforexaminingcrudematerialsthatareplannedtobepurifiedbydistillation-theseresultswillallowthechemisttodecideonamaximumtemperaturelimitforaprocess,thatwillnotgiverisetoathermalrunaway.Classicalthermo-analyticalmicromethods(DTA,DSC)arestillveryusefulforprocesswork,butmediumscaleinstrumentsbasedonheatflowmeasurementareattaininganincreasinglyimportantroleinthisdomain.Theapplicationofheatflowcalorimetryintheprocessofindustrialproductionhasbeenintroduced.Somepapersgiveoverviewsontheprinciplesofheatflowcontrolandreviewthedevelopmentsofthefiftiesandsixties,whenthematchingofheatflowwithheatreleasebyreactionswasthegoal.Withtheadventoffastandpowerfullaptopcomputers,thefocushasshifted.Now,thedeductionoftrueheatreleaseratesfromsignalswhichmaybebadlydistorted,isthegoal.Itmaybepossibletobuildacalorimeterfrominexpensivecomponents,butthedevelopmenteffortwillbehigh.Inaddition,networkthinkingmethodologyandGreyRelationalAnalysisarepopular,suchastheapplicationofnetworkthinkingmethodologyandGreyRelationalAnalysisinthelogisticprocesssafety.Aproposedversionofanetworkthinkingmethodologyfortheuseofasafetyanalysisoflogisticprocessesrealization,unlikeanoriginalProbstandUrlichconcept,onlyusesitsmodifiedstages.Asignificantelementwhichdifferentiatesasolutionistheuseofoneofgreysystemstheory’smethodssocalledGreyRelationalAnalysisinordertoquantitativelyformulateacommonexperts7opinionconcerninganimpactmutualforceofidentifiedfactors.Thesolutionwillbetestedwithreferencetorealdataforabuyingdecisionprocessinacompanyofachemicalbranchusingacomputersupportthatsimplifiescomputationprocesses.Inaresultofthisanalysis,ateamthatincludesfiveexpertswasformed.Theteamdeterminedgroupsofstakeholdersinadescribedprocessandtheirrequirementsconnectedwithasafetyofabuyerdecisionprocess.Onthebasisofstakeholders’requirements,theexpertsdetermined19factorsinfluencingalogisticprocesssafetyinsignificantway.Havingfactorsselected,theexpertsdevelopedanetworkinwhichdirectionsoffactors’interactionsandakindofinteractionweredetermined.Informationandcommunicationtechnologyprocessacertainroleinpromotingsafety.ICTcanreducetherateoferrorsbypreventingerrorsandadverseevents,facilitatingamorerapidresponseafteranadverseeventhasoccurred,andtrackingandprovidingfeedbackaboutadverseevents.Computerizingexistingprocesssafetytechniqueswillfacilitateeffectivenessinanalysisandidentificationriskfactors.ICTpotentialsincludeelectroniccommunication,synchronizationofworkflow,automationofactivitiesandreal-timeaccess/updateofdataorinformationthatcanimpactdecisionmakingandmanagementofprocesssafety.ICTimprovesprocesssafetythroughautomationandintegrationofprocesssafetyactivitiesandinformationforpromotionofsafetyandpreventionofdisaster.Processsafetymanagementisananalyticaltoolfocusedonpreventingreleasesofanysubstancedefinedasa"highlyhazardouschemicals"bytheEPAorOSHA.ProcessSafetyManagement(PSM)referstoasetofinter-relatedapproachestomanagehazardsassociatedwiththeprocessindustriesandisintendedtoreducethefrequencyandseverityofincidentsresultingfromreleasesofchemicalsandotherenergysources(USOSHA1993).Thesestandardsarecomposedoforganizationalandoperationalprocedures,designguidance,auditprograms,andahostofothermethods.ThereismanydecadeshavebeenspentsolelyinPSMpractice.TheheartandsoulofPSMinclude:ProcessSafetyInformation(PSI)PSIgenerallycomprisesmuchofthekeytechnicalandengineeringknowledgerelativetoprocesschemicals,technology,andequipment.ProcessHazardAnalysis(PHA)areintendedtoprovideacomprehensive,structuredreviewofrelevantPSIandproceduresinordertopostulateandrecommendmeansforaddressingsignificantlossofcontainmentscenarioshavingthepotentialtoimpactpeople,theenvironment,orinsomecases,thebusiness.OperatingProcedures(OP)especiallyformatureandwelldevelopedPSMprograms,MOCandPSSRareoftenviewedastwoofthemostcriticalPSMelements.ManagementofChangeMechanicalIntegrity(MI)closelytiedtotheconceptofmechanicalreliability,isuniversallyrecognizedasoneofthemostimpactfulelementsofafacility’sPSMprogram.ManagementSystemsAnydiscussionofauditsshouldencompassmorethanjusttheregulatoryrequiredtriennialPSMcomplianceaudits.Aneffectiveprocesssafetycultureisessentialtoaneffectiveprocesssafetymanagement(PSM)program.AgoodsafetycultureisthedifferencebetweendoingaPSMactivity,anddoingitwell.Withoutagoodculture,anorganizationcancheckofftheboxesindicatingthatvariousPSMactivitieshavebeendone,buttheproductofthoseactivitiesmayhavelittlevaluablecontent,andthePSMprogrammaynotbeeffective.Someintangiblefactorscanalsoaffecttheprocesssafety.Weknowhowtoimproveprocesssafetyperformance.Ourbiggestchallengeisnottechnical,itiscultural.Weneedtoactuallydowhatwealreadyknowhowtodo,weneedtodoitwell,andweneedtodoiteverywhereandallofthetime.Todothat,everybodyintheorganization,fromtheCEOtothenewesthourlyworkerintheplantneedstounder-standhisorherroleinPSM,andbelievethattheseactivitiesarevaluable,essential,andtheonlywaytowork.ProcessSafetyincreasinglyimportantinproductionandliving,soitisaverygooddevelopmentprospects.aDRmanagementmodel(DRmodel)isproposedbasedontheoriginalIBISmethod.ThisDRmodelcanrepresenttherelationshipbetweenthedesignintent,thethinkingprocessandthedesignresult(processinformation).Furthermore,asimplifiedsearchsystemisproposedasapartofthesafetymanagementsystem.ThissystemcangiveusefulinformationforthesafetybytheeasyquestionthroughtheProloginferenceengine.ProcessSafetywillbeaccompaniedaseriesofnewmanagementmodel.ThereareprobablyseveralreasonsforthatPSMcansometimesbecomequitefrustrating,wemustworktodevelop,implement,andmaintaineffective,functionalsystemsthatarenotanymorecomplicatedthantheyneedtobetogetthejobdone.Wemustneverallowourselvestobesatisfiedwithanythinglessthanthefullandproperexecutionofthesesystemsandactivities.Advancingprocesssafetyrequiresrethinkingtechnologiesnecessarytoensureadherencetoproceduresandeffectivelymonitoringofcompliance.Withtheadventofmobility,cloudandbigdataanalytics,newtoolsareavailabletodirectlyimpactprocesssafetyanditsimplementation.Keytosuccessfulimplementationistheabilitytocaptureandmonitoractivitiesatthemostgranularlevelofproceduraldetail-knowledge"onestepatatime."Generally,processsafetyautomationhasbeenconsideredtobetheresponsibilityofaspecializedsafetysystemandthatremainstrueforSafetyIntegrityLevelsafetyautomationrequirements.But,whatifthebasicautomationoftheprocesscouldbeconstructedinsuchawaythatitsignificantlyimprovedtheabilitytomaintaintheprocesswithinacceptableoperatinglimitsandnotreachtheconditionsthatwouldtriggeraresponsefromthesafetysystem?Allprocessesoperatebasedonprocedures,usuallywritten.Batch-basedprocessesmoreandmorerunonautomatedprocedures.But,evencontinuousprocessesconstantlyuseprocedures.Amongtheseareequipmentandunitstartupandshutdownprocedures,productorgradechangeprocedures,spareequipmentinandoutofserviceprocedures,qualitycontrolprocedures,alarmresponseprocedures,andmanymore.Frequently,therecanbesignificantbenefitstoautomatingahighpercentageoftheseprocedures.Safetyisoneofthosebenefitsandcanbederivedfromopportunitiesrangingfromconsistentandmistakeproofoperationstosimplyremovingtheneedforanoperatortobeexposedtopotentialprocessorphysicalhazards.Additionally,significantimpactscanberealizedonalarmmanagementbasedonproceduralcontrol.Pursuingprocesssafetyinaworldofcontinuouslyincreasingrequirementsisnotasimplematter.Keepingbalancebetweenproducingqualityandvolumeunderbudgetconstraintswhilemaintaininganadequatesafetylevelprovestimeandtimeagainadifficulttaskgiventhatevidentlymajoraccidentscannotbeavoided.Lackofresiliencefromanorganizationalpointofviewtoabsorbunwantedandunforeseendisturbanceshasinrecentyearsbeenputforwardasamajorcause,whileorganizationalerosivedriftisshowntoberesponsibleforcomplacencyanddegradationofsafetyattitude.Asystemsapproachtosafetyprovidesanewparadigmwiththepromiseofnewcomprehensivetools.Atthesametime,onerealizesthatriskassessmentwillfallshortofidentifyingandquantifyingallpossiblescenarios.First,humanerrorisinmostassessmentsnotincluded.Itisevenarguedthatdetermininghumanfailureprobabilitybydecomposingittobasicelementsoferrorisnotpossible.Second,thecruxofthesystemicapproachisthatsafetyisanemergentproperty,whichmeansthesameholdsforthetechnologicalaspect:riskisnotfullypredictablefromfailureofcomponents.Bysurveying