Flowcharacteristicsofcontrolvalves調(diào)節(jié)閥的流量特性落版在此謝聰XieCong主講教師Teacher調(diào)節(jié)閥的流量特性Flowcharacteristicsofcontrolvalves調(diào)節(jié)閥的流量特性Flowcharacteristicsofcontrolvalves關(guān)鍵部件Keycomponents調(diào)節(jié)閥的流量特性Flowcharacteristicsofcontrolvalves流量特性的理解和掌握，對于確保整個系統(tǒng)的穩(wěn)定運行和高效控制，具有至關(guān)重要的意義。

Understandingandmasteringflowcharacteristicsareofcrucialimportanceforensuringthestableoperationandefficientcontroloftheentiresystem.Flowcharacteristicsofcontrolvalves調(diào)節(jié)閥的流量特性當你擰開浴室的淋浴噴頭，為什么輕輕轉(zhuǎn)動旋鈕，水流會從涓涓細流突然變成噴涌的水柱？Whenyouturnontheshowerheadinthebathroom,whydoesagentleturnoftheknobsuddenlychangethewaterflowfromatrickletoagushingcolumn?調(diào)節(jié)閥就像“流體的指揮家”一樣，精準控制著工業(yè)生產(chǎn)和日常生活中的介質(zhì)流動。Controlvalvespreciselycontroltheflowofmediainindustrialproductionanddailylife,actinglike"conductorsoffluids".Flowcharacteristicsofcontrolvalves調(diào)節(jié)閥的流量特性當調(diào)節(jié)閥的閥芯移動時，流量是如何變化的？Whenthevalveplugofacontrolvalvemoves,howdoestheflowratechange?調(diào)節(jié)閥閥芯位移與流量之間的關(guān)系，對控制系統(tǒng)的控制品質(zhì)有很大影響。Therelationshipbetweenthedisplacementofthecontrolvalveplugandtheflowratehasasignificantimpactonthecontrolqualityofthecontrolsystem.Definitionofcontrolvalveflowcharacteristics調(diào)節(jié)閥流量特性的定義Definitionofcontrolvalveflowcharacteristics調(diào)節(jié)閥流量特性的定義被控介質(zhì)流過閥門的相對流量Q/Qmax與閥門的相對開度（相對位移）l/L之間的關(guān)系稱為調(diào)節(jié)閥的流量特性。TherelationshipbetweentherelativeflowrateQ/Qmax

ofthecontrolledmediumflowingthroughthevalveandtherelativeopening(relativedisplacement)l/Lofthevalveiscalledtheflowcharacteristicsofthecontrolvalve.

Q/Qmax

——相對流量Q/Qmax

——Relativeflowratel/L——相對開度l/L——Relativeopening下面分二種情況進行討論：Thiswillbediscussedintwocasesbelow：調(diào)節(jié)閥流量特性不僅與閥門結(jié)構(gòu)和開度有關(guān)，還與閥前后的壓差有關(guān)。Theflowcharacteristicsofacontrolvalveisnotonlyrelatedtothevalvestructureandopeningbutalsotothepressuredifferentialbeforeandafterthevalve.Definitionofcontrolvalveflowcharacteristics調(diào)節(jié)閥流量特性的定義Definitionofcontrolvalveflowcharacteristics調(diào)節(jié)閥流量特性的定義為了工程上分析方便Fortheconvenienceofengineeringanalysis先在閥前后壓差固定情況下，確定調(diào)節(jié)閥的固有流量特性。First,determinetheinherentflowcharacteristicsofthecontrolvalvewhenthepressuredifferentialbeforeandafterthevalveisfixed;再延伸到閥前后壓差變化的實際工況，確定調(diào)節(jié)閥工作流量特性。Extendittotheactualworkingconditionswherethepressuredifferentialbeforeandafterthevalvechangestodeterminetheworkingflowcharacteristicsofthecontrolvalve.調(diào)節(jié)閥固有（理想）流量特性Inherent(ideal)flowcharacteristicsofcontrolvalves常用流量特性Commonflowcharacteristics直線特性Linearcharacteristics等百分比特性Equalpercentagecharacteristics快開特性Quick-openingcharacteristics在將控制閥前后壓差固定時得到的流量特性稱為固有流量特性，它取決于閥芯的形狀。Theflowcharacteristicsobtainedwhenthepressuredifferentialbeforeandafterthecontrolvalveisfixedis

calledtheinherentflowcharacteristics,whichdependsontheshapeofthevalveplug.Definitionofcontrolvalveflowcharacteristics調(diào)節(jié)閥流量特性的定義調(diào)節(jié)閥固有（理想）流量特性Inherent(ideal)flowcharacteristicsofcontrolvalves常用流量特性Commonflowcharacteristics直線特性Linearcharacteristics等百分比特性Equalpercentagecharacteristics快開特性Quick-openingcharacteristicsDefinitionofcontrolvalveflowcharacteristics調(diào)節(jié)閥流量特性的定義Classificationofcontrolvalveflow調(diào)節(jié)閥流量的分類Classificationofcontrolvalveflow調(diào)節(jié)閥流量的分類調(diào)節(jié)閥的相對流量Q/Qmax與相對開度l/L成直線關(guān)系，即單位位移變化所引起的流量變化是常數(shù)。TherelativeflowrateQ/Qmax

ofthecontrolvalveisinalinearrelationshipwiththerelativeopeningl/L.Thatis,thechangeinflowratecausedbyaunitdisplacementchangeisaconstant.用數(shù)學(xué)式表示為：Itcanbeexpressedmathematicallyas:

R——調(diào)節(jié)閥可調(diào)比R——rangeabilityofthecontrolvalve直線流量特性Linearflowcharacteristics可調(diào)比R為調(diào)節(jié)閥所能控制的最大流量與最小流量的比值TherangeabilityRistheratioofthemaximumflowratethatthecontrolvalvecancontroltotheminimumflowrate.

指閥門全關(guān)時的泄漏量Refertotheleakageratewhenthevalveisfullyclosed閥門按照流量特性能進行連續(xù)平穩(wěn)控制的最小流量Theminimumflowrateatwhichthevalvecanperformcontinuousandstablecontrolaccordingtotheflowcharacteristics一般約為最大流量Qmax的2~4%，國產(chǎn)閥門的可調(diào)比一般為R=30。Itisgenerallyabout2-4%ofthemaximumflowrateQmax.TherangeabilityofdomesticvalvesisgenerallyR=30.直線流量特性LinearflowcharacteristicsClassificationofcontrolvalveflow調(diào)節(jié)閥流量的分類直線閥的流量放大系數(shù)在任何一點上都是相同的，但其對流量的控制力卻是不同的。Theflowamplificationcoefficientofalinearvalveisthesameatanypoint,butitscontrolforceovertheflowrateisdifferent.控制力指閥門開度改變時，相對流量的改變比值（%）。Controlforcereferstotheratio(%)ofthechangeintherelativeflowratewhenthevalveopeningischanged.直線流量特性LinearflowcharacteristicsClassificationofcontrolvalveflow調(diào)節(jié)閥流量的分類Q/Q100L/LmaxS=1S=1開度10％時：Atanopeningof10％:開度50％時：Atanopeningof50%:開度80％時：Atanopeningof80%:[(20-10)/10]×100%=100%[(60-50)/50]×100%=20%[(90-80)/80]×100%=12.5%直線流量特性Linearflowcharacteristics以直線閥為例TakingalinearvalveasanexampleClassificationofcontrolvalveflow調(diào)節(jié)閥流量的分類Q/Q100L/LmaxS=1S=1開度10％時：Atanopeningof10％:開度50％時：Atanopeningof50%:開度80％時：Atanopeningof80%:較小的開度變化能引發(fā)流量大幅改變，控制靈敏度高。Asmallchangeinopeningcancausealargechangeinflowrate,withhighcontrolsensitivity.相同開度變化對流量的影響減弱，控制效果趨于平緩。Theinfluenceofthesameopeningchangeontheflowrateweakens,andthecontroleffecttendstobegentle.[(20-10)/10]×100%=100%[(60-50)/50]×100%=20%[(90-80)/80]×100%=12.5%直線流量特性Linearflowcharacteristics以直線閥為例TakingalinearvalveasanexampleClassificationofcontrolvalveflow調(diào)節(jié)閥流量的分類單位相對行程變化l/L所引起的相對流量變化Q/Qmax與此點的相對流量成正比關(guān)系。TherelativeflowratechangeQ/Qmax

causedbyaunitrelativestrokechangel/Lisproportionaltotherelativeflowrateatthispoint。等百分比（對數(shù)）流量特性Equalpercentage(logarithmic)flowcharacteristics

Classificationofcontrolvalveflow調(diào)節(jié)閥流量的分類曲線斜率（放大系數(shù)）隨行程的增大而增大Theslopeofthecurve(amplificationcoefficient)increaseswiththeincreaseofthestroke.流量小時，流量變化?。籛hentheflowrateissmall,theflowratechangeissmall;流量大時，流量變化大。Whentheflowrateislarge,theflowratechangeislarge.Classificationofcontrolvalveflow調(diào)節(jié)閥流量的分類等百分比（對數(shù)）流量特性Equalpercentage(logarithmic)flowcharacteristics等百分比流量特性的調(diào)節(jié)閥在小開度時，對流量的調(diào)節(jié)較為平緩，不會因為微小的開度變化就導(dǎo)致流量大幅波動，有利于在低流量區(qū)域進行精確、穩(wěn)定的控制。Foracontrolvalvewithequalpercentageflowcharacteristics,whenitisatasmallopening,theadjustmentoftheflowrateisrelativelygentle,anditwillnotcauselargefluctuationsintheflowrateduetosmallopeningchanges,whichisconducivetopreciseandstablecontrolinthelowflowratearea.Classificationofcontrolvalveflow調(diào)節(jié)閥流量的分類等百分比（對數(shù)）流量特性Equalpercentage(logarithmic)flowcharacteristics例如：Forexample:在一些需要精細調(diào)節(jié)小流量的化工反應(yīng)過程中，能避免流量突變影響反應(yīng)進程。Insomechemicalreactionprocessesthatrequirefineadjustmentofsmallflowrates,itcanavoidsuddenchangesintheflowratefromaffectingthereactionprogress.在大開度時：隨著開度增加，流量變化逐漸增大，能夠快速響應(yīng)并調(diào)節(jié)大流量，滿足生產(chǎn)過程中對大流量快速調(diào)整的需求。Atalargeopening:Astheopeningincreases,thechangeintheflowrategraduallyincreases,enablingarapidresponseandadjustmentoflargeflowratestomeettheneedsforrapidadjustmentoflargeflowratesintheproductionprocess.Classificationofcontrolvalveflow調(diào)節(jié)閥流量的分類等百分比（對數(shù)）流量特性Equalpercentage(logarithmic)flowcharacteristics等百分比閥在各流量點的放大系數(shù)不同，但對流量的控制力卻是相同的。Theamplificationcoefficientsofanequalpercentagevalveatdifferentflowratepointsaredifferent,butitscontrolforceovertheflowrateisthesame.Q/Q100L/LmaxS=1S=1開度10％時：Atanopeningof10％:開度50％時：Atanopeningof50%:開度80％時：Atanopeningof80%:分別增加10%開度，計算相對流量變化比值。Iftheopeningisincreasedby10%respectively,calculatetheratiooftherelativeflowratechange.Classificationofcontrolvalveflow調(diào)節(jié)閥流量的分類等百分比閥在各流量點的放大系數(shù)不同，但對流量的控制力卻是相同的。Theamplificationcoefficientsofanequalpercentagevalveatdifferentflowratepointsaredifferent,butitscontrolforceovertheflowrateisthesame.Q/Q100L/LmaxS=1S=1開度10％時：Atanopeningof10％:開度50％時：Atanopeningof50%:開度80％時：Atanopeningof80%:（6.58%-4.68%）/4.68%≈41%（25.7%-18.2%）/18.2%≈41%（71.2%-50.6%）/50.6%≈41%Classificationofcontrolvalveflow調(diào)節(jié)閥流量的分類Q/Q100L/LmaxS=1S=1百分比閥在控制流量時，能夠在不同的流量范圍內(nèi)都保持相對穩(wěn)定的調(diào)節(jié)精度。Whencontrollingtheflowrate,apercentagevalvecanmaintainrelativelystableadjustmentaccuracyindifferentflowrateranges.對于負荷變化較大的控制系統(tǒng)具有很好的適應(yīng)性，能夠在小流量和大流量情況下都能實現(xiàn)較為精準的流量控制。Andhasgoodadaptabilitytocontrolsystemswithlargeloadchanges,achievingrelativelypreciseflowratecontrolinbothsmallandlargeflowratesituations.Classificationofcontrolvalveflow調(diào)節(jié)閥流量的分類開度較小時，隨開度的增大，流量迅速增大，很快就達到最大，故稱為快開特性。適用于迅速啟閉的切斷閥或雙位控制系統(tǒng)。Whentheopeningissmall,astheopeningincreases,theflowrateincreasesrapidlyandsoonreachesthemaximum,soitiscalledthequick-openingcharacteristics.Itissuitableforshut-offvalvesortwo-positioncontrolsystemsthatrequirerapidopeningandclosing.Classificationofcontrolvalveflow調(diào)節(jié)閥流量的分類快開特性Quick-openingcharacteristics其它針對特殊需求的流量特性，如拋物線特性（圖中藍色虛線），介于直線和對數(shù)曲線之間，實際工程使用較少（只在特殊情況下使用）。Otherflowcharacteristicsforspecialneeds,suchastheparaboliccharacteristiccurve(thebluedotted