大罐吹掃、干燥、預(yù)冷方案

靖邊西藍(lán)自然氣綜合利用工程10000靖邊西藍(lán)自然氣綜合利用工程10000M3LNG儲罐安裝工程靖邊西藍(lán)自然氣綜合利用工程10000M3LNG張家港中集圣達(dá)因低溫裝備202393日目錄1、SCOPE范圍CRITERIAOFPURGINGANDDRYING枯燥和吹掃標(biāo)準(zhǔn)3、PRELIMINARYCHECKSANDSET-UP初步的檢查和組織安排4、QUALITYOFNITROGENGAS氮氣質(zhì)量5、NITROGENPURGEANDDRYOUT氮氣吹掃和枯燥5.1、PurgeanddryoutinnertankZoneA(Step1)內(nèi)罐區(qū)域A吹掃和枯燥〔步驟1〕5.2、PurgeanddryoutzoneB(step2) 區(qū)域B吹掃和枯燥〔步驟2〕5.3、Purgeanddryoutbottom(step3) 底部吹掃和枯燥〔步驟3〕5.4、PurgeanddryoutofnozzlesandzoneB(step4)B吹掃與枯燥〔4〕6、PRODUCTGASPURGE產(chǎn)品氣體吹掃、Initialconditions初始條件、ProductGaspurgeZoneA(step5) 產(chǎn)品氣體吹掃區(qū)域A〔步驟5〕6.3、ProductgasPurge,ZoneB(step6) 產(chǎn)品氣體吹掃區(qū)域B〔步驟6〕6.4、‘Productgas’purgeofnozzles(Step7) 產(chǎn)品氣體吹掃管道〔步驟7〕7、COOL-DOWN冷卻、Initialconditions(step8) 初始條件〔步驟8〕、Cool-downprocess(step9) 冷卻過程〔步驟9〕8、AppendixA–ToolsandInstrumentsA-工具和儀表SCOPE 范圍Thisspecificationcoverstheprocedureforpurging,dryoutandcooldownofone10000capacity,singleintegrity,refrigeratedstoragetank,storingLNGat-163C.說明文件描述容積為一萬方、構(gòu)造完整、低溫儲罐、儲存LNG溫度為-163°C的儲罐，內(nèi)容為吹掃、枯燥以及冷卻程序Note:‘Product’statedinthisprocedurereferstoLNGAT-163°C.‘Productgas’statedinthisprocedurereferstowarm(ambienttemperature)LNGvapour.留意：所規(guī)定的“產(chǎn)品”指-163°CLNG，所規(guī)定的“產(chǎn)品氣體”指環(huán)境溫度下的LNG蒸汽。CRITERIAOFPURGINGANDDRYING 吹掃和枯燥標(biāo)準(zhǔn)ZONE區(qū)域A:INNERTANKANDDOMESPACE內(nèi)罐和頂部空間O2CONCENTRATION(VOL%)氧氣濃度<8%ZONE區(qū)域A:INNERTANKANDDOMESPACE內(nèi)罐和頂部空間O2CONCENTRATION(VOL%)氧氣濃度<8%DEWPOINT露點(ATATMOSPHERICPRESSURE)在大氣壓力下BELOW–20C低于-20°CB:ANNULARSPACE夾層<8%BELOW–20°C*NOTECriteriaofNitrogenpurgingusing‘Productgas’shallbeasfollows:ZONE區(qū)域ZONE區(qū)域N2CONCENTRATION(VOL氮氣濃度A:INNERTANKANDDOMESPACE內(nèi)罐和頂部空間<8%DEWPOINT露點(ATATMOSPHERICPRESSURE)在大氣壓力下BELOW–20C低于-20°CB:ANNULARSPACE夾層<8%BELOW–20°C*NOTE低于-20°C*注釋

體吹掃和*Note:-20°CofthedewpointinzoneBisspecifiedasatargetvalue.IfthedewpointinzoneBhasnotreacheditstargetvaluebuthasexceeded–10°Cafterthescheduleddryingandpurgingthentheoperationmayproceedtothenextstep. *注釋：區(qū)域B中的露點-20°C是規(guī)定的目標(biāo)值。假設(shè)區(qū)域B10C，那么操作可以進入下一步驟。PRELIMINARYCHECKSANDSET-UP 初步檢查和組織安排Allspecifiedtestingandinspectionworksshallhavebeencompletedandacceptedpriortocommencementofthedryingandpurgingoperation.全部測試和檢查工作應(yīng)當(dāng)在吹掃和枯燥程序開頭之前全部完成以及被確認(rèn)。Alltemporaryandpermanentinstrumentationandprotectiondevicessuchasreliefvalvesandvacuumbreakervalvesshallhavebeeninstalled,checkedforoperationandcalibrated.全部臨時的和永久的儀表以及安全設(shè)備，例如安全閥、真空斷路閥，都應(yīng)安裝好，以檢查動作調(diào)整狀況。Thetankinsulationworkshallhavebeencompleted.儲罐絕熱工作已經(jīng)完成。Priortofinalclosingup,thetankshouldbevisuallyinspectedtoensurethatitiscleanandfreefromanyforeignmatterandthatallthefittingsandinstrumentsarecorrectlyinstalledandcheckedforproperoperation.配件和儀表是否正確安裝EnsureNitrogengasfacilityhasbeenprovidedtoallowNitrogengastobesuppliedtopurgeinputnozzlesN15andN4.確保氮氣設(shè)備供給的氮氣能夠供給置換輸入管口N15和N4Downwardbentpipesorpropercanopiesshallbeprovidedatallventnozzlestopreventwaterinvasion.向下的彎頭或者適宜的罩子應(yīng)安裝在全部的管口上以避開水的進入AnylocationwherethereisdangerofsuffocationcausedbyventedNitrogen/‘Productgas’shouldbeclearlymarkedwithdangersignsandbarriers.Portablegasdetectorsandbreathingapparatusshallbelocatedattheseareas.任何有窒息危急的位置〔因排放氮氣/產(chǎn)品氣體而導(dǎo)致窒息〕應(yīng)當(dāng)清楚地以危急符號和柵欄為標(biāo)記，便攜式氣體檢測器和通氣供氧設(shè)備應(yīng)放在這些位置區(qū)域Duringpurginganddryingthetank,pressureshouldbecontrolledtomaintainapressureofaround300-600mmH2O.在吹掃和枯燥儲罐的過程中，壓力應(yīng)被掌握在300-600mmH2O左右Atemporarymanometershouldbeinstalledtomonitortheoperatingpressure.安裝一臺U管壓力計用來監(jiān)測運行時的壓力QUALITYOFNITROGENGAS 氮氣質(zhì)量Thetankshouldbepre-driedwithdryairpriortopurgingwithNitrogengas.儲罐應(yīng)用枯燥空氣在用氮氣吹掃前進展預(yù)枯燥AirandanyremainingmoistureinsidethetankshallbepurgedwithdryNitrogengas.儲罐內(nèi)空氣和任何剩余水分應(yīng)用枯燥氮氣吹掃TheNitrogengastobeusedforOxygenpurginganddryingshallbesuppliedaccordingtothefollowingspecification:用于吹掃和枯燥氧氣的氮氣應(yīng)按以下的技術(shù)要求來供給：PurityPurity純度Dewpoint露點Flowrate流量>98%<-60°C300-600nmchnmch=normalisedmetre3perhourNITROGENPURGEANDDRYOUT 氮氣吹掃和枯燥PurgeanddryoutinnertankZoneA(Step1)A吹掃和枯燥〔1〕Monitorthetankpressureduringpurgeanddryout.在吹掃和枯燥過程中監(jiān)測儲罐壓力EnsureNitrogenbottompurgevalveN4,annuluspurgevalveN16andBottompurgevalvesN23A&Bareclosedduringpurgeofinnertank.確保底部進氣閥N4、夾層排氣閥N16、底部排氣閥N23A&B在吹掃內(nèi)罐的過程中是關(guān)閉的。Openvalveonpurgeinletnozzle(N15)andintroduceNitrogengasintotheinnertank.翻開N15管口上的閥門，吹掃氮氣通過此管口進入內(nèi)罐。Whentheinnertankpressurereaches400m2Hopenthevalveonpurgeventnozzle(N17)anddischargethepurgegastoatmosphere.400mmHO時，翻開吹掃排放管口N17上的閥門，吹掃氣體從今管2口排放出去。EnsurethattheNitrogengasissuppliedataratebetween300to600hr.Startpurgeatthelowerrateandgraduallyincreaseafter4hours.300600Nm3/hr之間，在較低比率時開頭吹掃，在4小時后漸漸上升。MonitortheO2concentrationandthedewpointoftheventedNitrogengasatN17.WhentheO2concentrationanddewpointoftheventedNitrogengasatN17isapproachingtherequiredlevelsasdefinedinsection2abovethenproceedtothenextsection(step2).監(jiān)測N172局部定義的要求時，然后進入下一步驟〔步驟2。PurgeanddryoutzoneB(step2)B吹掃和枯燥〔2〕WhentheOxygenconcentrationatN17islessthan8%duringpurgeoftheinnertankandroofspaceasdescribedaboveopenthevalveN16tocommencepurgingofzoneB.當(dāng)在N17位置在內(nèi)罐和頂部空間吹掃過程中如上表達(dá)氧氣濃度低于8%時，翻開N16閥門開頭吹掃區(qū)域BWARNING,ENSUREALLPRECAUTIONSAREINPLACETOENSUREALLPERSONNELAREPROTECTEDFROMSUFFOIONFROMNITROGENDURINGTHEPURGEOPERATION.警告，確保全部預(yù)防措施到位以保證全部人員受到防護，避開在吹掃過程中因氮氣導(dǎo)致窒息。MonitortheO2concentrationandthedewpointoftheventedNitrogengasatN17.監(jiān)視N17排放出氮氣中的氧氣濃度和露點WhentheventedgasanddewpointoftheventedNitrogengasatN17arebelowtherequiredlevelsasdefinedinsection2abovereducethesupplyrateofNitrogenandthenclosenozzleN17.ThesupplyrateoftheNitrogenshouldbeadjustedtoavoidoverpressurisingtheoutertank.Itisimportanttopurgetheannularspaceslowlytoavoidthepurgegastunnellingthroughtheresilientblanketalone.當(dāng)排放氣體和N17位置排放氮氣的露點低于在第2量然后關(guān)閉管口N17。氮氣供氣量應(yīng)調(diào)整以避開對外罐施加過多的壓力。緩慢置換夾層是很重要的，要避開產(chǎn)生隧道效應(yīng)〔吹掃氣體只單獨穿過彈性毯〕Proceedtothenextsection(step3). 進入下一步驟〔3〕Purgeanddryoutbottom(step3)底部吹掃和枯燥〔步驟3〕WhentheOxygenconcentrationatN16islessthan10%duringpurgeoftheannularspaceasdescribedaboveopenvalvesN4,N23A&Btocommencepurgingofthebottominsulation.當(dāng)吹掃夾層過程中如上所述N1610%時，翻開N4、N23A&B閥門開頭吹掃底部絕熱層。WARNING,ENSUREALLPRECAUTIONSAREINPLACETOENSUREALLPERSONNELAREPROTECTEDFROMSUFFOIONFROMNITROGENDURINGTHEPURGEOPERATION.警告，確保全部預(yù)防措施到位以保證全部人員受到防護，避開在吹掃過程中因氮氣導(dǎo)致窒息。MonitortheO2concentrationandthedewpointoftheventedNitrogengasatN23A&B.監(jiān)測N23A&B排放氮氣中氧氣濃度和露點WhentheconcentrationanddewpointoftheventedNitrogengasatN23A&Bisbelowtherequiredlevelsasdefinedinsection2abovethenclosenozzlesN4,N23A&BandreducethesupplyrateofNitrogen.ThesupplyrateoftheNitrogenshouldbeadjustedtoavoidoverpressurisingtheoutertank.當(dāng)N23A&B排放氮氣的濃度和露點低于如上所述其次局部中定義的要求時，關(guān)閉管口N4、N23A&B，以及降低氮氣供氣量。氮氣供氣量應(yīng)被調(diào)整以避開對外罐施加過多的壓力Proceedtothenextsection(step4). 進入下一步驟〔4〕PurgeanddryoutofnozzlesandzoneB(step4)B吹掃與枯燥〔4〕DuringthepurgingofzoneBpurgeoutallnozzlesandrooftoppiping.Openeachvalveonallnozzles,pipingandappurtenancestopurgeanyentrappedair.在吹掃區(qū)域B時，吹掃全部管口和頂部管道，翻開全部管口、管道、附件的閥門進展吹掃任何位置夾帶的空氣。MonitortheO2concentrationandthedewpointoftheventedNitrogengasateachpoint.在每一位置監(jiān)測排放氮氣的氧氣濃度和露點。WhentheventedgasanddewpointoftheventedNitrogengasateachpurgepointisbelowtherequiredlevelsasdefinedinsection2abovethenclosetherelevantvalve.2局部所定義的要求時，關(guān)閉相關(guān)閥門。Closeallvalvesonallnozzles,pipingandappurtenances.關(guān)閉全部管口、管道、附件的閥門。ClosethepurgesupplyvalveN15.關(guān)閉吹掃氣體供給閥N15。ClosetheannularpurgevalveN16. 關(guān)閉夾層放氣閥N16PRODUCTGASPURGE 產(chǎn)品氣體吹掃Initialconditions 初始條件Ensureallpermanentpressureandvacuumreliefvalvesareoperational.確保全部的固定壓力和真空解除閥是可使用的。Disconnectalltemporarypiping,ifany,associatedwithNitrogenpurginganddryout.假設(shè)有與氮氣吹掃和枯燥相關(guān)的臨時性管道，全部撤除。Ensurethatallinstruments,suchasthefollowingareinoperationalcondition.確保全部儀表是可使用的，例如如下幾種：Temperaturesensors. 溫度傳感器Thetankgaugingsystems. 儲罐度量系統(tǒng)Pressuresensors. 壓力傳感器ProductGaspurgeZoneA(step5)A〔5〕EnsureannuluspurgevalveN16isclosedafterNitrogenpurgeofinnertank.確保在內(nèi)罐氮氣吹掃之后夾層放氣閥N16是關(guān)閉的。Ensurewarm(ambienttemperature)‘Productgas’isconnectedandavailabletotheproductsupplylineeitherviatheprocessorviatheinjectionpointonthepiperack.確保環(huán)境溫度下“產(chǎn)品氣體”已經(jīng)通過管線輸送到儲罐，并能滿足吹掃需要量。OpenthevalveontheboiloffgasoutletnozzleN6toventtheNitrogengasinthetank,replacingitwithwarm(ambienttemperature)‘Productgas’.翻開管口N6的BOG閥門以排放儲罐內(nèi)的氮氣，用環(huán)境溫度下的“產(chǎn)品氣體”置換罐內(nèi)的氮氣。OpenthebottomproductinletvalveN2andintroduce‘Productgas’intothetank.翻開底部進液閥N2引導(dǎo)產(chǎn)品氣體進入儲罐。Warning:ensurethatonlywarmproductgasisallowedintothetankatthisstage.Onnoaccountshouldcoldproductbeintroducedintothelin.e確保在這階段中進入儲罐的是環(huán)境溫度下的產(chǎn)品氣體，切莫使冷的產(chǎn)品氣體進入供給線。Monitortheconcentrationof‘Productgas’intheboiloffgasline.監(jiān)測BOG管線上“產(chǎn)品氣體”的濃度。Whenthe‘Productgas’concentrationreaches92%openN17topurgethedomespaceofNitrogen.當(dāng)“產(chǎn)品氣體”的濃度到達(dá)92%，翻開N17以吹掃頂部空間的氮氣ProductgasPurge,ZoneB(step6)B〔6〕WhentheNitrogenconcentrationatN17islessthan8%duringpurgeoftheinnertankandroofspaceasdescribedabove,openthevalveN16tocommencepurgingofzoneB.當(dāng)內(nèi)罐和頂部空間吹掃過程中N178%，翻開N16閥門開頭吹掃區(qū)域BMonitortheN2concentrationandthedewpointoftheventedNitrogengasatN16.監(jiān)測N16位置排放氮氣的氮氣濃度和露點WhentheventedgasanddewpointoftheventedNitrogenatN16isbelowtherequiredlevelsasdefinedinsection2abovethenclosenozzleN17andreducethesupplyrateof‘Productgas’.Thesupplyrateofthe‘Productgas’shouldbetoavoidpressurisingtheoutertank.Itisimportanttopurgetheannularspaceslowlytoavoidthepurgegastunnellingthroughtheresilientblanketalone.當(dāng)排放氣體以及N162局部所定義的要求時，關(guān)閉管口N17和降低“產(chǎn)品氣體”的供給量過多的壓力，緩慢置換夾層是很重要的，要避開產(chǎn)生隧道效應(yīng)。‘Productgas’purgeofnozzles(Step7)產(chǎn)品氣體吹掃管口〔7〕AfterclosingnozzleN17,purgeoutthenozzlesandrooftoppiping.Openeachvalveonallnozzles,pipingandappurtenancestopurgeanyentrappedNitrogen.在關(guān)閉管口N17之后吹掃管口和頂部管道，翻開全部管口、管道、附件的閥門以吹掃任何夾帶氮氣。MonitortheN2concentrationandthedewpointoftheventedNitrogengasatN16.監(jiān)測N16位置排放氮氣的氮氣濃度和露點。WhentheventedgasanddewpointoftheventedNitrogengasateachpurgepointisbelowtherequiredlevelsasdefinedinsection2abovethenclosetherelevantvalve.當(dāng)各位置排放氣體和排放氮氣的露點低于第2局部所定義的要求時，關(guān)閉相關(guān)閥門Closeallvalvesonallnozzles,pumpcolumns,pipingandappurtenances.關(guān)閉全部管口、泵柱、管道和附件處的閥門。ClosetheProductsupplyvalveN2. 關(guān)閉產(chǎn)品氣體供給閥N2。ClosethePurgevalveN16. 關(guān)閉放氣閥N16。ClosetheBoiloffgasvalveN6. BOG閥門N6。Re-installblankingflangesforinservicearrangementofnozzleswhereappropriate.相關(guān)的吹掃管口重安裝盲法蘭以實現(xiàn)使用中對管口的要求。COOL-DOWN冷卻Initialconditions(step8) 初始條件〔8〕Thetankshallbecooleddownatacontrolledratetopreventthermalstressingoftheinnertank.儲罐冷卻應(yīng)受到掌握，以預(yù)防內(nèi)罐熱應(yīng)力收縮太大。Thefollowingparametersgoverntheoperation. 以下因素掌握操作要求。Innertankcoolingshallbecontrolledat3perhour.Maximumpermissiblecoolingmeasuredatanythermocoupleshallnotexceed°perhour.內(nèi)罐冷卻掌握在每小時3°C5°CThemaximumdifferentialtemperaturesbetweenadjacentthermocouplesshallnotbegreaterthan20C.20°CThemaximumdifferentialtemperaturesacrossallthermocouplesshallnotbegreaterthan50C.50°CThetankpressureshallnotexceedtheoperatingpressure.儲罐壓力不應(yīng)超過工作壓力。RecommendedCooldownusingproduct. 推舉用產(chǎn)品冷卻Assumedstarttemperature假設(shè)開頭溫度 35°CFlowrateforcooldownspraynozzle凝噴嘴流量 32l/minat3bare凝噴嘴流量 42l/minat5barEstimatedtimeforcooldown卻估量時間 228hoursEstimatedquantityofLNGrequiredforcooldown 185tonnesLNG估量需求量罐底液體根部 300mm147m3EstimatedquantityofLNGforliquidheel 62tonnesLNG液體根部估量數(shù)量TotalquantityofLNGLNG總量(cooldown+liquidheel)〔冷卻用+液體根部〕 247tonnesTankavailablefortheintroductionofproduct `LNGLNGCooldown185tonnesofLNGrequired32lpm3bar41.9lpm5b