重型卡車SCR排放系統(tǒng)中英文版 201510

EngineApplicationDepartmentofC&CTrucksCo.,Ltd.ResearchInstitute

陶兵文2015年10月

TaoBingwenOctober,20150排氣后處理系統(tǒng)簡介ExhaustSolutionSystemIntroduction

第一部分概述Chapter1Overview第二部分系統(tǒng)構(gòu)造與原理Chapter2SystemConstruction&OperatingPrinciple第三部分主要部件功用及工作原理Chapter3FunctionsandOperatingPrincipleofMainComponents第四部分使用注意事項Chapter4Useattention第五部分故障診斷及排除Chapter5FaultDiagnosisAndTroubleshooting1目錄Contents1、排氣后處理系統(tǒng)的功用：FunctionsofExhaustSolutionSystem:①保證發(fā)動機最佳性能的同時，把發(fā)動機所有燃燒廢氣安全地運離發(fā)動機；①Toensurethebestperformanceoftheengine，combustionexhaustgasdeliveredtotheenginesafelyatthesametime；②消減發(fā)動機產(chǎn)生的排氣噪聲以滿足法規(guī)和客戶對噪音要求；②Reduceexhaustnoisegeneratedbytheenginetomeettherequirementsofregulationsandcustomers③降低或消除發(fā)動機燃燒產(chǎn)生的污染物以滿足法規(guī)和客戶要求；③Reduceoreliminatethepollutantsgeneratedbyenginecombustioninordertomeetregulationsandcustomerrequirements;2、排氣后處理系統(tǒng)的技術(shù)類型：TypesofExhaustSolutionSystem:①選擇催化還原技術(shù)簡介：選擇性催化還原是一項針對柴油發(fā)動機排氣的NOx控制技術(shù)。這個反應(yīng)需要在一個催化器里向排氣中噴入尿素（一種易于分解為氨的氮化合物）。尿素被加熱后產(chǎn)生的氨與NOx發(fā)生發(fā)應(yīng)，生成無害的氮氣(N2)和水(H20)。①SCR：Selective

Catalytic

ReductionIntroduction:SelectivecatalyticreductionisaNOxcontroltechniquefordieselengineexhaust.TheprocessinvolvestheinjectionofUrea(anitrogenouscompoundwhichreadilydecomposesintoammonia)intotheexhaustoveracatalystconvertor.TheammoniareactswithNOxandproducesharmlessnitrogen(N2)andwater(H20).2一、概述Chapter1Overview注意：這里所說的添藍就是指：“尿素”Note:

TheAdbluesaidhereis:"urea"3、排氣后處理系統(tǒng)的組成：ComponentsofExhaustSolutionSystem:①添藍供給裝置：如添藍罐、添藍溶液傳感器、添藍管路、添藍噴射泵等①Adbluesupplydevice:suchasadbluetank、adbluesensor、adbluehose②空氣供給裝置：如儲氣罐、油氣分離器、尼龍管等②Airsupplydevice:suchasairtank、oil&airfilter、PAhose③系統(tǒng)加熱裝置：如防凍液電磁閥、EPDM管路、添藍溶液傳感器等③Systemheatingdevice:suchascoolantcontrolvalve、EPDMhoseandadbluesensor④

排氣催化還原裝置：如催化消聲器、排氣管等④Exhaustcatalyticreductiondevice:suchasexhasutgasprocessor、exhaustpipe⑤系統(tǒng)控制裝置：如DCU、NOx傳感器、前溫度傳感器、后溫度傳感器等⑤Systemcontroldevice:suchasDCU、NOxsensor、catalystinputtemperaturesensor、catalystoutputtemperaturesensor3一、概述Chapter1Overview4、SCR后處理系統(tǒng)關(guān)鍵總成件：KeyassemblyofSCRsystem:催化消聲器Exhaustgasprocessor添藍噴嘴Ureainjectornozzle噴嘴扣壓螺母Nozzlenut添藍噴射泵UreadoserUnit防凍液電磁閥Coolantcontrolvalve油氣分離器Oil&airfilter排氣管Exhaustpipe添藍罐帶添藍溶液傳感器Ureatankwhitureasensor添藍管路Ureahoses氮氧傳感器NOxsensorSCR控制模塊Dosingcontrolunit前溫度傳感器CatalystinputT-sensor后溫度傳感器CatalystoutputT-sensor

第一部分概述Chapter1Overview第二部分系統(tǒng)構(gòu)造與原理Chapter2SystemConstruction&OperatingPrinciple第三部分主要部件功用及工作原理Chapter3FunctionsandOperatingPrincipleofMainComponents第四部分使用注意事項Chapter4Useattention第五部分故障診斷及排除Chapter5FaultDiagnosisAndTroubleshooting4目錄Contents二、排氣后處理系統(tǒng)—構(gòu)造Chapter2、ExhaustSolutionSystem—construction添藍供給裝置Adbluesupplydevice空氣供給裝置Airsupplydevice系統(tǒng)控制裝置Systemcontroldevice排氣裝置Exhaustcatalyticreductiondevice系統(tǒng)加熱裝置systemheatingdevice發(fā)動機Engine電源線Powerlines信號線signallines加熱管Heatlines添藍管Adbluelines空氣管AirlinesCAN線CANlines8車輛儲氣罐9油氣分離器10進氣管11出氣管22NOx傳感器催化器Catalyticconverter17排氣管18催化消聲器（EGP）發(fā)動機廢氣流向箭頭Exhaustflowarrow19排氣尾管1.Ureatank2.UreadoserUnit3.Ureainjectornozzle4.Ureasupplyhose5.Ureareturnhose6.Ureapressurehose7.Ureasensor添藍供給裝置Adbluesupplydevice26蓄電池?＋－?空氣供給裝置Airupplydevice8.Airtank9.Oil&airfilter10.Airinhose11.Airouthose化冰解凍裝置Icethawingdevice12.Engine13.Coolantcontrolvalve14.Coolantinhose15.Coolantouthose16.Coolantreturnhose7.Ureasensor排氣催化還原裝置ExhaustCatalyticreductiondevice17.Exhaustpipe18.ExhaustGasprocessor19.Exhausttailpipe系統(tǒng)控制裝置Systemcontroldevice20.CatalystinputT-sensor21.CatalystoutputT-sensor22.NOxsensor23.Dosingcontrolunit24.Enginecontrolunit25.Heatingrelay26.Battery27.Ignitionswitch23DCU24ECU21后溫傳感器20前溫傳感器3添藍噴嘴1添藍罐2添藍噴射泵4進液管5回液管6噴射管7添藍傳感器14進水管15出水管12發(fā)動機13防凍液電磁閥16加熱回水管25加熱繼電器27.點火開關(guān)二、排氣后處理系統(tǒng)—構(gòu)造Chapter2、ExhaustSolutionSystem—construction系統(tǒng)工作原理：簡單地說，系統(tǒng)的工作原理如下：

AdBlue存放在一個安裝在底盤上的罐中。此罐向計量泵(DU)供應(yīng)溶液，后者也安裝在底盤上。DU由SCR控制模塊（DCU），DCU和發(fā)動機控制模塊(ECM)關(guān)聯(lián)通訊。DU使用來自車輛系統(tǒng)的壓縮空氣使AdBlue霧化，并通過非常精確的計量和泵送系統(tǒng)輸送到發(fā)動機排氣系統(tǒng)內(nèi)的噴嘴。DCU控制著噴入排氣中的AdBlue數(shù)量，在任何指定轉(zhuǎn)速和負載條件下，將其與發(fā)動機的NOx排放量相匹配。與熾熱的排氣一接觸，水就迅速蒸發(fā)，尿素變成氨。氨與NOx在催化轉(zhuǎn)換器內(nèi)發(fā)生發(fā)應(yīng)，這一過程的結(jié)果就是從排氣管中排放出無害的氮氣(N2)和水(H20)。Systemwork

principle：Brieflydescribed,thesystemfunctionsasfollows:TheAdBlueisstoredinachassismountedtank.ThetanksuppliesthesolutiontoaDosingUnit(DU)whichisalsochassismounted.TheDUiselectronicallycontrolledbytheUosingcontrolunit（DCU）whichrelatestotheenginecontrolmodule(ECM).TheDUusescompressedairsuppliedfromthevehiclesystemtoatomizetheAdBlueandbymeansofaveryaccuratepumpingandmeteringsystem,suppliesaspraynozzleintheengine’sexhaustsystem.TheamountofAdBlueinjectedintotheexhaustiscontrolledbytheDCUandmatchedtotheNOxoutputoftheengineatanygivenspeedandloadcondition.Waterevaporatesquicklyandtheureaturnsintoammoniawhenincontactwithhotexhaustgases.TheammoniareactswithNOxoverthecatalystconvertorandtheresultanttailpipeemissionfromthisprocessisharmlessnitrogen(N2)andwater(H20).二、排氣后處理系統(tǒng)—構(gòu)造Chapter2、ExhaustSolutionSystem—construction二、排氣后處理系統(tǒng)原理&構(gòu)造—添藍供給裝置Chapter2、Principle&construction—Adbluesupplydevice添藍罐Adbluetank添藍溶液傳感器Adbluesensor添藍進液管Adbluesupplyhose添藍回液管Adbluereturnhose添藍噴射管AdbluePressurehose添藍噴射泵AdbluedoserUnit原理圖Principlefigure3添藍噴嘴1添藍罐2添藍噴射泵4進液管5回液管6噴射管7添藍傳感器1.Ureatank2.Ureadoserunit3.Ureainjectornozzle4.Ureasupplyhose5.Ureareturnhose6.Ureapressurehose7.Ureasensor添藍供給裝置Adbluesupplydevice車輛布置圖Vehiclelayoutfigure工作原理：添藍罐中的添藍溶液通過添藍溶液傳感器，由進液管輸送給添藍噴射泵，然后通過噴射管送給噴嘴噴霧到排氣管中，與發(fā)動機廢氣混合；為防止泵的壓力過高，多余的添藍溶液通過回液管返回至添藍罐；Work

principle:Theureasolutioninureatankistransferredfromureasupplyhosetoureadoserunitbyureasolutionsensor，andthenthroughureapressurehosetotheexhaustpipe,wheremixwiththeengineexhaustgas;Theexcessureasolutionreturntoureatankbyreturnhose，topreventthepumppressureofureadoserunitistoohigh。8車輛儲氣罐9油氣分離器10進氣管11出氣管空氣供給裝置Airupplydevice8.Airtank9.Oil&airfilter10.Airinhose11.Airouthose工作原理：儲氣罐中的高壓空氣通過進氣管進入油氣分離器，然后輸送給添藍噴射泵，與噴射泵中的尿素溶液混合，作為尿素噴射的主要動力源。Work

principle:Thehighpressureairintheairstoragetankisusedtoentertheoil&airfilterthroughairinhose，andthentransporttoureadoserunit；Theairmixwithureainureadoserunit，whichisusedasmainpowersourceforureainjection.儲氣罐Airtank進氣管Airinhose出氣管Airouthose油氣分離器Oil&airfilter原理圖Principlefigure車輛布置圖Vehiclelayoutfigure二、排氣后處理系統(tǒng)原理&構(gòu)造—空氣供給裝置Chapter2、Principle&construction—Airsupplydevice工作原理：當系統(tǒng)檢測添藍溶液溫度低于0℃時，系統(tǒng)加熱功能啟動，直至添藍溶液溫度達到3℃才停止加熱。Work

principle:Theureasolutiontemperaturewillbemonitoredandifthetemperatureislessthan0degreestheheaterwillbeengaged.Theheaterwillremainonuntilthetemperatureincreasesto3degrees.發(fā)動機Engine防凍液電磁閥Engine電磁閥進水管Coolantinhose電磁閥出水管Coolantouthose加熱系統(tǒng)回水管Coolantreturnhose添藍溶液傳感器Ureasensor原理圖Principlefigure車輛布置圖Vehiclelayoutfigure12發(fā)動機1添藍罐2添藍噴射泵4進液管5回液管7添藍傳感器14進水管15出水管13防凍液電磁閥16加熱回水管＋－化冰解凍裝置Icethawingdevice12.Engine13.Coolantcontrolvalve14.Coolantinhose15.Coolantouthose16.Coolantreturnhose7.Ureasensor2.UreadoserUnit4.Ureasupplyhose5.Ureareturnhose二、排氣后處理系統(tǒng)原理&構(gòu)造—系統(tǒng)加熱裝置Chapter2、Principle&construction—Systemheatingdevice工作原理：當添藍溶液傳感器探測到尿素溶液溫度低于0℃時，防凍液電磁閥閥門開啟，熱的發(fā)動機防凍液通過電磁閥進水管流經(jīng)防凍液電磁閥，然后通過電磁閥出水管進入到尿素傳感器加熱螺旋管，給添藍罐中的尿素溶液加熱，最后通過加熱系統(tǒng)回水管返回至發(fā)動機參與冷卻循環(huán)，如此周而復始的循環(huán)加熱尿素溶液，防止尿素溶液結(jié)冰，保證SCR系統(tǒng)尿素溶液的正常供給。Work

principle:Whentheureasolutionsensordetectureatemperatureoflessthan0degrees,

thecoolantcontrolvalveisopened,hotenginecoolantflowfromcoolantinhosetothecoolantcontrolvalve,andthenthroughthecoolantouthoseintoureasolutionsensorheatingspiraltube,soureaintankisheated，throughcoolantreturnhoseofheatingsystemtotheengineincirculatingcoolingfinally,sogoroundandbeginagain,topreventureasolutionfreeze,andensurethenormalsupplyofureasolutionforSCR.發(fā)動機Engine防凍液電磁閥Engine電磁閥進水管Coolantinhose電磁閥出水管Coolantouthose加熱系統(tǒng)回水管Coolantreturnhose添藍溶液傳感器Ureasensor原理圖Principlefigure車輛布置圖Vehiclelayoutfigure12發(fā)動機1添藍罐2添藍噴射泵4進液管5回液管7添藍傳感器14進水管15出水管13防凍液電磁閥16加熱回水管＋－化冰解凍裝置Icethawingdevice12.Engine13.Coolantcontrolvalve14.Coolantinhose15.Coolantouthose16.Coolantreturnhose7.Ureasensor4.Ureasupplyhose5.Ureareturnhose二、排氣后處理系統(tǒng)原理&構(gòu)造—系統(tǒng)加熱裝置Chapter2、Principle&construction—Systemheatingdevice工作原理：添藍溶液加熱器集成在添藍溶液傳感器中，為螺旋結(jié)構(gòu)，增大了加熱器與尿素溶液的接觸面積，提高了解凍效率。Work

principle:Inordertoimprovetheefficiencyoftheheatingprocess,ureasolutionheaterisintegratedintheureasolutionsensor,whichisaspiralstructureforincreasingthecontactareabetweentheheaterandtheureasolution.發(fā)動機Engine防凍液電磁閥Engine電磁閥進水管Coolantinhose電磁閥出水管Coolantouthose加熱系統(tǒng)回水管Coolantreturnhose添藍溶液傳感器Ureasensor原理圖Principlefigure車輛布置圖Vehiclelayoutfigure12發(fā)動機1添藍罐2添藍噴射泵4進液管5回液管7添藍傳感器14進水管15出水管13防凍液電磁閥16加熱回水管＋－化冰解凍裝置Icethawingdevice12.Engine13.Coolantcontrolvalve14.Coolantinhose15.Coolantouthose16.Coolantreturnhose7.Ureasensor4.Ureasupplyhose5.Ureareturnhose二、排氣后處理系統(tǒng)原理&構(gòu)造—系統(tǒng)加熱裝置Chapter2、Principle&construction—Systemheatingdevice工作原理：添藍罐中的尿素溶液被加熱的同時，添藍進液管和回液管也同時啟動電加熱功能，以保證尿素管路因結(jié)冰堵塞。添藍噴射泵自帶加熱解凍功能。Work

principle:

Theureasolutionhasbeenheatedinureasupplyhoseandureareturnhosebytheelectricheatingfunctionwhenureasolutionintankisheatedatthesametime.Theureadoserunithasaselfcontrolledheatingelementasstandard.發(fā)動機Engine防凍液電磁閥Engine電磁閥進水管Coolantinhose電磁閥出水管Coolantouthose加熱系統(tǒng)回水管Coolantreturnhose添藍溶液傳感器Ureasensor原理圖Principlefigure車輛布置圖Vehiclelayoutfigure12發(fā)動機1添藍罐2添藍噴射泵4進液管5回液管7添藍傳感器14進水管15出水管13防凍液電磁閥16加熱回水管＋－化冰解凍裝置Icethawingdevice12.Engine13.Coolantcontrolvalve14.Coolantinhose15.Coolantouthose16.Coolantreturnhose7.Ureasensor2.UreadoserUnit4.Ureasupplyhose5.Ureareturnhose二、排氣后處理系統(tǒng)原理&構(gòu)造—系統(tǒng)加熱裝置Chapter2、Principle&construction—Systemheatingdevice二、排氣后處理系統(tǒng)原理&構(gòu)造—排氣催化還原裝置Chapter2、Principle&construction—Exhaustcatalyticreductiondevice催化器Catalyticconverter17排氣管18催化消聲器（EGP）發(fā)動機廢氣流向箭頭Exhaustflowarrow19排氣尾管12發(fā)動機排氣催化還原裝置ExhaustCatalyticreductiondevice17.Exhaustpipe18.Exhaustgasprocessor19.Exhausttailpipe12.Engine原理圖Principlefigure車輛布置圖Vehiclelayoutfigure催化消聲器Exhaustgasprocessor排氣管Exhaustpipe排氣管尾管Exhausttailpipe發(fā)動機Engine尿素NH2CONH2加H2O后在高溫下分解成NH3和CO2過程：

蒸發(fā)：1）NH2CONH2（水溶液）->NH2-CO-NH2（融化的液態(tài)）+H2O（gas）熱分解：2）NH2-CO-NH2（融化的液態(tài)）->NH3（gas）+HNCO（gas）水解：3）NH2CONH2

（gas）+H2O（gas）->2NH3（gas）+CO2（gas）TheprocessofNH2CONH2andCO2beingdecomposedintoNH3andCO2athightemperature:Evaporation:1）NH2CONH2（Aqueoussolution）->NH2-CO-NH2（Meltedliquid）+H2O（gas）Thermaldecompositio:2）NH2-CO-NH2（Meltedliquid）->NH3（gas）+HNCO（gas）Hydrolysis:3）NH2CONH2

（gas）+H2O（gas）->2NH3（gas）+CO2（gas）二、排氣后處理系統(tǒng)原理&構(gòu)造—排氣催化還原裝置Chapter2、Principle&construction—Exhaustcatalyticreductiondevice催化器Catalyticconverter17排氣管18催化消聲器（EGP）發(fā)動機廢氣流向箭頭Exhaustflowarrow19排氣尾管12發(fā)動機原理圖Principlefigure車輛布置圖Vehiclelayoutfigure催化消聲器Exhaustgasprocessor排氣管Exhaustpipe排氣管尾管Exhausttailpipe發(fā)動機EngineNH3和排氣中的NO和NO2反應(yīng)產(chǎn)生氮氣和水：4）NO+NO2+2NH3->2N2+3H2O5）4NO+O2+4NH3->4N2+6H2O6）2NO2+O2+4NH3->3N2+6H2ONH3reactwithNOxinexhaustgastoproducenitrogenandwater:4）NO+NO2+2NH3->2N2+3H2O5）4NO+O2+4NH3->4N2+6H2O6）2NO2+O2+4NH3->3N2+6H2O系統(tǒng)控制裝置Systemcontroldevice20.CatalystinputT-sensor21.CatalystoutputT-sensor22.NOxsensor23.Dosingcontrolunit24.Enginecontrolunit25.Heatingrelay催化器Catalyticconverter18催化消聲器（EGP）1添藍罐2添藍噴射泵7添藍傳感器13防凍液電磁閥23DCU24ECU21后溫傳感器20前溫傳感器＋－22NOx傳感器25加熱繼電器工作原理：DCU檢測發(fā)動機和排氣后處理系統(tǒng)的工作狀況，當達到相應(yīng)工況條件后，SCR系統(tǒng)開始噴射尿素，SCR系統(tǒng)進入正式催化還原工作狀態(tài)，達到降低排放污染物的要求。Workprinciple:DCUdetectstheworkconditionofengineandexhaustsolutionsystem,theSCRsystembegantosprayureasolutionwhenreachingthespecificallyconditions.theSCRsystemturnintotheformalcatalyticreductionoftheworkingstateforreducingthepollutantsofexhaustgas.原理圖Principlefigure車輛布置圖Vehiclelayoutfigure控制模塊Dosingcontrolunit防凍液電磁閥Coolantcontrolvalve前溫度傳感器CatalystinputT-sensor添藍溶液傳感器Ureasensor前溫度傳感器CatalystoutputT-sensorNOx傳感器NOxsensor二、排氣后處理系統(tǒng)原理&構(gòu)造—系統(tǒng)控制裝置Chapter2、Principle&construction—Systemcontroldevice系統(tǒng)控制裝置Systemcontroldevice20.CatalystinputT-sensor21.CatalystoutputT-sensor22.NOxsensor23.Dosingcontrolunit24.Enginecontrolunit25.Heatingrelay催化器Catalyticconverter18催化消聲器（EGP）1添藍罐2添藍噴射泵7添藍傳感器13防凍液電磁閥23DCU24ECU21后溫傳感器20前溫傳感器＋－22NOx傳感器25加熱繼電器SCR系統(tǒng)進入正式催化還原工作狀態(tài)，需滿足以下7個條件：SCRsystemintotheformalcatalyticreductionoftheworkingstate,thefollowing7conditionsshouldbemet:條件1：尿素水溶液溫度至少大于7℃；Condition1:ureawatersolutiontemperatureisatleast7centigrade;條件2：氮氧傳感器狀態(tài)值為“正?！保籆ondition2:thestateofthenitrogenoxygensensoris"normal";條件3：發(fā)動機轉(zhuǎn)速大于650rpm；Condition3:enginespeedisgreaterthan650rpm;原理圖Principlefigure車輛布置圖Vehiclelayoutfigure控制模塊Dosingcontrolunit防凍液電磁閥Coolantcontrolvalve前溫度傳感器CatalystinputT-sensor添藍溶液傳感器Ureasensor前溫度傳感器CatalystoutputT-sensorNOx傳感器NOxsensor二、排氣后處理系統(tǒng)原理&構(gòu)造—系統(tǒng)控制裝置Chapter2、Principle&construction—Systemcontroldevice系統(tǒng)控制裝置Systemcontroldevice20.CatalystinputT-sensor21.CatalystoutputT-sensor22.NOxsensor23.Dosingcontrolunit24.Enginecontrolunit25.Heatingrelay催化器Catalyticconverter18催化消聲器（EGP）1添藍罐2添藍噴射泵7添藍傳感器13防凍液電磁閥23DCU24ECU21后溫傳感器20前溫傳感器＋－22NOx傳感器25加熱繼電器條件4：發(fā)動機負荷大于3%；Condition4:engineloadgreaterthan3%;條件5：大氣壓力大于90kpa；Condition5:atmosphericpressuregreaterthan90kpa;條件6：排溫大于200℃；Condition6:rowtemperaturegreaterthan200;條件7：發(fā)動機水溫大于60℃。Condition7:enginewatertemperatureisgreaterthan60degrees.原理圖Principlefigure車輛布置圖Vehiclelayoutfigure控制模塊Dosingcontrolunit防凍液電磁閥Coolantcontrolvalve前溫度傳感器CatalystinputT-sensor添藍溶液傳感器Ureasensor前溫度傳感器CatalystoutputT-sensorNOx傳感器NOxsensor二、排氣后處理系統(tǒng)原理&構(gòu)造—系統(tǒng)控制裝置Chapter2、Principle&construction—Systemcontroldevice

第一部分概述Chapter1Overview

第二部分系統(tǒng)構(gòu)造與原理Chapter2SystemConstruction&OperatingPrinciple第三部分主要部件功用及工作原理Chapter3FunctionsandOperatingPrincipleofMainComponents第四部分使用注意事項Chapter4Useattention第五部分故障診斷及排除Chapter5FaultDiagnosisAndTroubleshooting19目錄Contents三、主要部件功用及工作原理Chapter3、FunctionsandOperatingPrincipleofMainComponents

DEF是什么？1.DEF-柴油排氣處理液（通常說的尿素，Adblue）2.32.5%的尿素水溶液3.無色，有淡淡的氨氣味，無毒4.水分蒸發(fā)后會結(jié)晶5.對碳鋼，銅，鋅等有腐蝕性6.零下11攝氏度會結(jié)冰7.詳細特性見ISO22241-1：2006或者中國標準29518-2013WhatisDEF?1.DEF–DieselExhaustFluid(a.k.a.Urea,Adblue)2.AmixofwaterandUrea(32.5%)3.Isaclearliquidsolution,faintsmellofammonia,classifiedbychemicalindustryasnon-hazardous4.Ifspilledwaterevaporatesandcrystalswillform5.Ischemicallyasaltcorrosivewhichcanattackmildsteel,brass,copperandzinc6.Startstofreezeat-11degrees7.Spec.asperDIN70070orChinaGB29518-2013尿素溶液濃度與冰點的關(guān)系Relationshipbetweenconcentrationofureasolutionandfreezingpoint

SCR后處理系統(tǒng)使用尿素質(zhì)量濃度為32.5%的尿素水溶液（AUS32）作為還原劑，其重要原因就是：尿素溶液在此濃度下結(jié)冰溫度最低（-11℃），如圖所示。

為什么車用尿素溶液量濃度要求為32.5%？Whydoesthecaruseureasolutionconcentrationrequirementis32.5%?三、主要部件功用及工作原理Three、FunctionsandOperatingPrincipleofMainComponentsUreasolutionattheconcentrationof32.5%icetemperatureminimum(-11℃),whichisthemainreasonofusingUreasolutionattheconcentrationof32.5%asareducingagentfortheSCRsystem,asshowninfig.三、主要部件功用及工作原理Chapter3、FunctionsandOperatingPrincipleofMainComponents

催化消聲器催化消聲器(EGP)是在密封不銹鋼殼體或“罐”內(nèi)的一個整體式催化和消聲裝置。EGP內(nèi)串聯(lián)的三個截然不同的元件分別是氨擴散器、催化器和消聲裝置。擴散器負責將氨均勻分散在催化器表面上。催化器負責NOx轉(zhuǎn)化的化學反應(yīng)，而消聲裝置則消減排氣系統(tǒng)的噪聲。（見圖右圖）催化器內(nèi)的化學反應(yīng)依賴于溫度（最低200°C）。ExhaustGasProcessor(EGP)Theexhaustgasprocessor(EGP)isanintegratedcatalystandacousticunitinonesealedstainlesssteelhousingor‘can’.Thethree,inseries,distinctelementsintheEGPareammoniadiffuser,catalystandacousticunit.Thediffuseractstoevenlydistributetheammoniaoverthecatalystface.ThecatalystperformsthechemicalprocessofNOxconversionandtheacousticunitmufflestheexhaustsystemnoise.(seeFigright)Thechemicalprocessinthecatalystistemperaturedependant(200oCmin.)氨擴散器Ammoniadiffuser催化器Catalyst消聲裝置Acousticunit

催化消聲器的主要作用是催化氮氧化合物的還原反應(yīng)和降低發(fā)動機的排氣噪聲，是SCR催化器和發(fā)動機排氣消聲器的集成體。整體材料為不銹鋼，內(nèi)裝SCR催化器芯子和消聲管路，運行過程中表面平均溫度高于200℃。法蘭面接口為入口，另一光管接口為出口。催化消聲器設(shè)計有前后兩個溫度傳感器安裝座，在催化后設(shè)計有NOx傳感器安裝座。催化器前后都要裝溫度傳感器,溫度傳感器外形如右圖所示。為防止插錯，催化器前后溫度傳感器插接件不同，前溫傳感器是圓形，后溫傳感器是方形，安裝時請辨別催化器進出口溫度傳感器的位置。ThemainfunctionoftheEGPisthereductionofthenitrogenoxidecompoundandthereductionoftheengineexhaustnoise.ItistheintegrationoftheSCRcatalystandtheengineexhaustmuffler.Thematerialismadeofstainlesssteel,installedintheSCRcatalyticconvertercoreandmufflerpipeline,runningaveragesurfacetemperaturehigherthan200degrees.Theflangeinterfaceistheentrance,andtheotheristheoutletoftheinterface.TheEGPdesignhastwotemperaturesensorinstallation,inthecatalyticdesignofNOxsensorinstallationseat.BothbeforeandaftertheEGPhasatemperaturesensor,thetemperaturesensorconfigurationisshowninfigright.Topreventthewrong,thesensorshavedifferentconnectors，CatalystinputT-sensorisround,theCatalystoutputT-sensorissquare,pleaseidentifysensorposition.前溫度傳感器CatalystinputT-sensor后溫度傳感器CatalystoutputT-sensor前溫安裝座InputT-sensorinstallation進氣口Exhaustinput后溫安裝座OutputT-sensorinstallation出氣口ExhaustoutletNOx安裝座Noxsensorinstallation三、主要部件功用及工作原理Chapter3、FunctionsandOperatingPrincipleofMainComponents

三個傳感器總成：消聲器前溫度傳感器總成消聲器前溫度傳感器總成NOx傳感器總成1.催化器上的溫度傳感器用來決定什么時間催化器達到需要溫度以實現(xiàn)化學反應(yīng)，并以此啟動尿素的計量與噴射；2.NOx傳感器實時監(jiān)測尾氣中NOx的排放量是否滿足排放要求，并反饋給DCU，用于尿素計量的計算參數(shù)之一。Threesensors:1.ThetemperaturesensorontheEGPisusedtodeterminewhattimethecatalystisneededtoachievethedesiredtemperatureinordertoachieveachemicalreaction,andtostartthemeasurementandinjectionofurea;2.NOxsensorinreal-timemonitoringofNOxemissionsintheexhaustgasemissionsrequirements,andfeedbacktotheDCU,tocalculationparametersforureameasurement.氮氧傳感器NOxsensor前溫度傳感器CatalystinputT-sensor后溫度傳感器CatalystoutputT-sensor三、主要部件功用及工作原理Chapter3、FunctionsandOperatingPrincipleofMainComponents②添藍溶液傳感器Ureasensor①通氣裝置Vent③加注口蓋Fillingcover④觀察窗Levelshow⑤排水孔Drainhole⑥罐體Tankbody

添藍罐總成（帶添藍溶液傳感器）主要結(jié)構(gòu)組成與功能：①通氣裝置：維持罐體內(nèi)和罐體外壓力平衡②添藍溶液傳感器：監(jiān)測尿素液位和溫度，密封添藍罐③添藍罐口蓋：密封添藍罐，便于實現(xiàn)添藍罐實時的尿素加注要求，加注口集成70μm自清潔式過濾器，以防通過加注頸管進入的雜物損壞系統(tǒng)④液位觀察窗：人工加注尿素時，通過觀察窗口液位顯示控制尿素加注量，防止尿素加注過滿⑤排水孔：定期清理罐體中的殘渣和污垢⑥罐體：盛載尿素溶液Ureatank（integratedureasensor）Mainstructureandfunction:①Ventdevice:maintaintankinsideandoutsidepressurebalance②Ureasolutionsensor:monitoringofurealiquidlevelandtemperature,sealingUreatank③Fillingcover:sealingUreatank,itiseasytofilladblueintoUrea

tankreal-timemeetingfillingrequirements.

Thefillerneckofthetankhasafiltersizedat70microntopreventingressofmaterialwhichmaygetinviathefillerneck.④Urealevelshow:Whenmanualfillingurea,controlstheureafillingquantitythroughtheurealevelshowwindow,preventstheureafillingover⑤Drainhole:cleaningtheresidueanddirtofthetankregularly⑥Tankbody:loadingureasolution三、主要部件功用及工作原理Chapter3、FunctionsandOperatingPrincipleofMainComponents

添藍罐中的關(guān)鍵總成件-添藍溶液傳感器總成監(jiān)測罐內(nèi)尿素溶液溫度，通過發(fā)動機熱水（防凍液）對罐內(nèi)尿素溶液化冰加熱，保證尿素溶液的正常供給；監(jiān)測罐內(nèi)液位高度，并按照預(yù)設(shè)液位高度向后處理系統(tǒng)控制模塊發(fā)出報警信號；

KeycomponentinUreatank-Ureasolutionsensormonitorthetemperatureofureasolutioninthetank,keeptheureasolutionnormaltemperaturebyheatingthroughenginehotcoolant,andensurethenormalsupplyofureasolutionMonitortheheightofliquidlevelintheUreatank,andsendoutthealarmsignaltotheDCUmoduleaccordingtothepresetparameter顯示液位高低原理：磁化的浮筒感應(yīng)電子管內(nèi)的磁簧管開關(guān)，改變電阻輸出的大小，通過阻值變化反應(yīng)箱體中的液體高度變化Displayliquidlevelprinciple:changethesizeoftheoutputresistancethroughtheMagneticfloatinducingthemagneticreedswitchintube;TheresistancechangedisplayliquidheightchangeintheUreatank顯示液體溫度原理：NTC熱敏電阻隨溫度變化，輸出不同阻值，通過阻值變化反應(yīng)罐內(nèi)溶液的溫度變化Displayliquidtemperatureprinciple:TheNTCthermistoroutputdifferentresistancewithdifferenttemperatureoftheUreatanksolution磁鋼浮筒Magneticfloat添藍溶液傳感器Ureasensor溫度傳感器Temperaturesensor三、主要部件功用及工作原理Chapter3、FunctionsandOperatingPrincipleofMainComponents

端口應(yīng)用Application起點From終點To管路規(guī)格HosesizeA尿素出液口Ureasupply添藍罐Ureatank噴射泵DUSAE9.49B尿素回液口Ureareturn噴射泵DU添藍罐UreatankSAE7.89C防凍液進液口Coolantin發(fā)動機取水口Engineout添藍罐UreatankΦ14×2.5D防凍液出液口Coolantout添藍罐Ureatank發(fā)動機回水口EngineinΦ14×2.5E線束WiringABCDE三、主要部件功用及工作原理Chapter3、FunctionsandOperatingPrincipleofMainComponents

添藍罐總成（帶添藍溶液傳感器）

SCR反應(yīng)所需的氨取自于質(zhì)量濃度為32.5%的尿素水溶液(AdBlue)。供應(yīng)罐的尺寸應(yīng)使AdBlue量相當于燃油消耗量5%（歐4安裝類型）的工作用量，而對于歐5估算值約為7%。

適用的罐材料有不銹鋼、鎂鋁合金或中高密度的聚乙烯。推薦使用不透明罐，使操作員不能觀察液位。這能確保診斷顯示空罐時它仍留有足量AdBlue，以免計量泵吸入空氣。

Ureatank（Ureasensorintegrated）TheammoniarequiredfortheSCRprocessisobtainedfromasolutionof32.5%(byweight)ureainwater(AdBlue).TheUreatankshouldbesizedtosuitanoperationaluseofureaequivalentto5%offuelconsumptionforEuro4installationsandanestimated7%forEuro5.Suitabletankmaterialsarestainlesssteel,magnesiumaluminiumalloyormedium-highdensitypolyethylene.Itisrecommendedthatthetankisnon-transparentsuchthattheoperatorcannotseethelevel.Thisistoensurethatwhenthetankshowsemptydiagnostically,itwillstillhaveasignificantamountofurealefttoavoidthedosingunitdrawingair.②添藍溶液傳感器Ureasensor①通氣裝置Vent③加注口蓋Fillingcover④觀察窗Levelshow⑤排水孔Drainhole⑥罐體Tankbody三、主要部件功用及工作原理Chapter3、FunctionsandOperatingPrincipleofMainComponents

添藍罐總成（帶添藍溶液傳感器）

供應(yīng)罐應(yīng)與大氣保持雙向低壓通風，使出口接頭的液體自由流動，并排出罐內(nèi)的所有蒸汽或膨脹氣體。通氣口設(shè)計應(yīng)使其不受罐濺出或蒸發(fā)過程中生成的結(jié)晶AdBlue導致堵塞的影響。目前還沒有發(fā)生道路事故時車輛翻傾防濺方面的法規(guī)，但是需要關(guān)注未來法規(guī)的發(fā)展。添藍罐有一個排液孔，以便進行定期維護。

Ureatank（Ureasensorintegrated）Theureatankshouldbeventedatlowpressurebothtoandfromatmospheretoallowfreeflowfromtheoutletconnectionandtoventanyvapourorexpansioninthetank.Theventshouldbedesignedsuchthatitisnotsusceptibletoblockagebycrystallizedureaformedduringtanksloshandevaporation.Thereisnoknownregulationonanti-spillforvehicleroll-overintheeventofaroadaccident;howeverthisneedstobemonitoredforfuturedevelopmentsinthelegislation.TheUreatankhasadrainholeforperiodicservicing.②添藍溶液傳感器Ureasensor①通氣裝置Vent③加注口蓋Fillingcover④觀察窗Levelshow⑤排水孔Drainhole⑥罐體Tankbody三、主要部件功用及工作原理Chapter3、FunctionsandOperatingPrincipleofMainComponents

安裝孔（4個）Mountinghole（four）壓縮空氣進口（A）CompressedAirinlet37針接頭（J1939)尿素進液口（C）Ureainlet空氣電磁閥接口Airsolenoidvalveinterface尿素回液（D）Ureareturn尿素出液（B）Air&Ureamixoutlet添藍噴射泵總成添藍噴射泵泵(DU)是高精度裝置，用于將所需尿素溶液量噴入排氣后處理系統(tǒng)中。該部件應(yīng)輕拿輕放。如果跌落可能會損壞。由DCU控制的24V電動泵和計量系統(tǒng)與車輛壓縮空氣系統(tǒng)送來的空氣一起協(xié)作，推動霧化的尿素溶液充入排氣系統(tǒng)催化器上游的噴嘴中。應(yīng)注意空氣電磁閥是一個直接使用取自加料泵12V電源的12V裝置?？諝庀牧繛?7.5–22L/min。（標準條件）。不論是否加注AdBlue，空氣消耗都是持續(xù)的。

UreadoserUnitThedosingunit(DU)isahighaccuracyunitforinjectingtherequiredAdBluequantityintotheexhaustafter-treatmentsystem.Thiscomponentshouldbehandledwithcare.Itmaybedamagedifdropped.A24velectronicallyoperatedpumpandmeteringsystem(controlledbytheDCU)workincombinationwithairfromthevehiclecompressedairsystemtopropeltheatomizedAdBluechargethroughanozzleintotheexhaustsystemupstreamofthecatalyst.Itshouldbenotedthattheairvalvesolenoidisa12voltunitwiththe12voltpowersourcecomingfromthedosingpumpdirectly.Theairconsumptionis17.5–22litres/min.(standardconditions).ThisairconsumptioniscontinuouswhetherAdBlueisbeingdosedornot.

三、主要部件功用及工作原理Chapter3、FunctionsandOperatingPrincipleofMainComponents

1.空氣閥（由電磁閥控制）2.4bar壓力下的空氣壓力調(diào)節(jié)閥3.量孔4.空氣單向閥（ACV）5.背壓閥（BPV）6.混合室7.出口單向閥（彈簧承載）8.促動膜片9.進口單向閥（彈簧承載）10.壓力開關(guān)11.空氣促動閥Ⅰ空氣裝置Ⅱ混合閥Ⅲ膜片泵A.與車輛空氣系統(tǒng)連接（壓縮空氣進氣管）B.與添藍噴嘴連接（添藍噴射管）C.與添藍罐連接（添藍進液管）D.與添藍罐連接（添藍回液管）ⅠⅡⅢ安裝孔（4個）Mountinghole（four）壓縮空氣進口（A）CompressedAirinlet37針接頭（J1939)37pinconnector（J1939）尿素進液口（C）Ureainlet空氣電磁閥接口Airsolenoidvalveinterface尿素回液（D）Ureareturn尿素出液（B）Air&Ureamixoutlet三、主要部件功用及工作原理Chapter3、FunctionsandOperatingPrincipleofMainComponents1.添藍噴射泵的4種工作模式-預(yù)注模式1.FouroperatingmodesofDU—PRIMNGMODE每次發(fā)動機運轉(zhuǎn)，添藍泵將進入預(yù)注階段。添藍溶液通過泵循環(huán)并流回到添藍罐中，以便排空添藍系統(tǒng)中殘留的空氣與尿素溶液混合物。如果預(yù)注階段成功，將會聽到添藍泵電機全速運轉(zhuǎn)30秒，空氣電磁閥將在本階段末工作。如果預(yù)注階段第一次不成功，空氣電磁閥將斷電，電機將再全速運轉(zhuǎn)30秒直到預(yù)注成功。這一順序可以重復最多20次。

Everytimetheenginerunning,theDUwillcomeintoprimingmodephase.Ureasolutionthroughthecirculationpumpandflowbacktoureatank,to